| <!DOCTYPE html> |
| <html lang="en-US" data-theme="light"> |
| <head> |
| <meta charset="utf-8" /> |
| <meta name="viewport" content="width=device-width,initial-scale=1" /> |
| <meta name="generator" content="VuePress 2.0.0-beta.61" /> |
| <meta name="theme" content="VuePress Theme Hope" /> |
| <link rel="alternate" hreflang="zh-cn" href="https://iotdb.apache.org/zh/UserGuide/V0.13.x/Process-Data/Triggers.html"><meta property="og:url" content="https://iotdb.apache.org/UserGuide/V0.13.x/Process-Data/Triggers.html"><meta property="og:site_name" content="IoTDB Website"><meta property="og:title" content="Triggers"><meta property="og:description" content="The trigger provides a mechanism for listening to changes in time series data. With user-defined logic, tasks such as alerting, data cleaning, and data forwarding can be conduct..."><meta property="og:type" content="article"><meta property="og:locale" content="en-US"><meta property="og:locale:alternate" content="zh-CN"><script type="application/ld+json">{"@context":"https://schema.org","@type":"Article","headline":"Triggers","image":[""],"dateModified":null,"author":[]}</script><link rel="icon" href="/favicon.ico"><meta name="Description" content="Apache IoTDB: Time Series Database for IoT"><meta name="Keywords" content="TSDB, time series, time series database, IoTDB, IoT database, IoT data management,时序数据库, 时间序列管理, IoTDB, 物联网数据库, 实时数据库, 物联网数据管理, 物联网数据"><meta name="baidu-site-verification" content="wfKETzB3OT"><meta name="google-site-verification" content="mZWAoRY0yj_HAr-s47zHCGHzx5Ju-RVm5wDbPnwQYFo"><title>Triggers | IoTDB Website</title><meta name="description" content="The trigger provides a mechanism for listening to changes in time series data. With user-defined logic, tasks such as alerting, data cleaning, and data forwarding can be conduct..."> |
| <style> |
| :root { |
| --bg-color: #fff; |
| } |
| |
| html[data-theme="dark"] { |
| --bg-color: #1d1e1f; |
| } |
| |
| html, |
| body { |
| background: var(--bg-color); |
| } |
| </style> |
| <script> |
| const userMode = localStorage.getItem("vuepress-theme-hope-scheme"); |
| const systemDarkMode = |
| window.matchMedia && |
| window.matchMedia("(prefers-color-scheme: dark)").matches; |
| |
| if (userMode === "dark" || (userMode !== "light" && systemDarkMode)) { |
| document.documentElement.setAttribute("data-theme", "dark"); |
| } |
| </script> |
| <link rel="preload" href="/assets/style-13611a3c.css" as="style"><link rel="stylesheet" href="/assets/style-13611a3c.css"> |
| <link rel="modulepreload" href="/assets/app-f2ec2f8e.js"><link rel="modulepreload" href="/assets/framework-5638dcb2.js"><link rel="modulepreload" href="/assets/Triggers.html-4cc5c5e6.js"><link rel="modulepreload" href="/assets/Triggers.html-06efa1d3.js"> |
| </head> |
| <body> |
| <div id="app"><!--[--><!--[--><!--[--><span tabindex="-1"></span><a href="#main-content" class="skip-link sr-only">Skip to main content</a><!--]--><!--[--><div class="theme-container has-toc"><!--[--><header class="navbar hide-icon" id="navbar"><div class="navbar-start"><button class="toggle-sidebar-button" title="Toggle Sidebar"><span class="icon"></span></button><!--[--><!----><!--]--><a href="/" class="brand"><img class="logo" src="/logo.png" alt="IoTDB Website"><!----><span class="site-name hide-in-pad">IoTDB Website</span></a><!--[--><!----><!--]--></div><div class="navbar-center"><!--[--><!----><!--]--><!--[--><!----><!--]--></div><div class="navbar-end"><!--[--><!----><!--]--><div id="docsearch-container"></div><nav class="nav-links"><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="Documentation"><span class="title"><!---->Documentation</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="/UserGuide/Master/QuickStart/QuickStart.html" class="nav-link" aria-label="latest"><!---->latest<!----></a></li><li class="dropdown-item"><a href="/UserGuide/V1.1.x/QuickStart/QuickStart.html" class="nav-link" aria-label="v1.1.x"><!---->v1.1.x<!----></a></li><li class="dropdown-item"><a href="/UserGuide/V1.0.x/QuickStart/QuickStart.html" class="nav-link" aria-label="v1.0.x"><!---->v1.0.x<!----></a></li><li class="dropdown-item"><a href="/UserGuide/V0.13.x/QuickStart/QuickStart.html" class="nav-link" aria-label="v0.13.x"><!---->v0.13.x<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><a href="https://cwiki.apache.org/confluence/display/IOTDB/System+Design" rel="noopener noreferrer" target="_blank" aria-label="Design" class="nav-link"><!---->Design<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="nav-item hide-in-mobile"><a href="/Download/" class="nav-link" aria-label="Download"><!---->Download<!----></a></div><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="Community"><span class="title"><!---->Community</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="/Community/About.html" class="nav-link" aria-label="About"><!---->About<!----></a></li><li class="dropdown-item"><a href="https://cwiki.apache.org/confluence/display/iotdb" rel="noopener noreferrer" target="_blank" aria-label="Wiki" class="nav-link"><!---->Wiki<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="/Community/Community-Project-Committers.html" class="nav-link" aria-label="People"><!---->People<!----></a></li><li class="dropdown-item"><a href="/Community/Community-Powered-By.html" class="nav-link" aria-label="Powered By"><!---->Powered By<!----></a></li><li class="dropdown-item"><a href="/Community/Materials.html" class="nav-link" aria-label="Resources"><!---->Resources<!----></a></li><li class="dropdown-item"><a href="/Community/Feedback.html" class="nav-link" aria-label="Feedback"><!---->Feedback<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="Development"><span class="title"><!---->Development</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="/Development/VoteRelease.html" class="nav-link" aria-label="How to vote"><!---->How to vote<!----></a></li><li class="dropdown-item"><a href="/Development/HowToCommit.html" class="nav-link" aria-label="How to Commit"><!---->How to Commit<!----></a></li><li class="dropdown-item"><a href="/Development/HowToJoin.html" class="nav-link" aria-label="Become a Contributor"><!---->Become a Contributor<!----></a></li><li class="dropdown-item"><a href="/Development/Committer.html" class="nav-link" aria-label="Become a Committer"><!---->Become a Committer<!----></a></li><li class="dropdown-item"><a href="/Development/ContributeGuide.html" class="nav-link" aria-label="ContributeGuide"><!---->ContributeGuide<!----></a></li><li class="dropdown-item"><a href="/Development/HowtoContributeCode.html" class="nav-link" aria-label="How to Contribute Code"><!---->How to Contribute Code<!----></a></li><li class="dropdown-item"><a href="/Development/format-changelist.html" class="nav-link" aria-label="Changelist of TsFile"><!---->Changelist of TsFile<!----></a></li><li class="dropdown-item"><a href="/Development/rpc-changelist.html" class="nav-link" aria-label="Changelist of RPC"><!---->Changelist of RPC<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="ASF"><span class="title"><!---->ASF</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="https://www.apache.org/" rel="noopener noreferrer" target="_blank" aria-label="Foundation" class="nav-link"><!---->Foundation<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/licenses/" rel="noopener noreferrer" target="_blank" aria-label="License" class="nav-link"><!---->License<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/security/" rel="noopener noreferrer" target="_blank" aria-label="Security" class="nav-link"><!---->Security<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/sponsorship.html" rel="noopener noreferrer" target="_blank" aria-label="Sponsorship" class="nav-link"><!---->Sponsorship<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/thanks.html" rel="noopener noreferrer" target="_blank" aria-label="Thanks" class="nav-link"><!---->Thanks<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/events/current-event" rel="noopener noreferrer" target="_blank" aria-label="Current Events" class="nav-link"><!---->Current Events<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li></ul></button></div></div></nav><div class="nav-item"><div class="dropdown-wrapper i18n-dropdown"><button class="dropdown-title" type="button" aria-label="Select language"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon i18n-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="i18n icon" style="width:1rem;height:1rem;vertical-align:middle;"><path d="M379.392 460.8 494.08 575.488l-42.496 102.4L307.2 532.48 138.24 701.44l-71.68-72.704L234.496 460.8l-45.056-45.056c-27.136-27.136-51.2-66.56-66.56-108.544h112.64c7.68 14.336 16.896 27.136 26.112 35.84l45.568 46.08 45.056-45.056C382.976 312.32 409.6 247.808 409.6 204.8H0V102.4h256V0h102.4v102.4h256v102.4H512c0 70.144-37.888 161.28-87.04 210.944L378.88 460.8zM576 870.4 512 1024H409.6l256-614.4H768l256 614.4H921.6l-64-153.6H576zM618.496 768h196.608L716.8 532.48 618.496 768z"></path></svg><!--]--><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html" class="router-link-active router-link-exact-active nav-link active" aria-label="English"><!---->English<!----></a></li><li class="dropdown-item"><a href="/zh/UserGuide/V0.13.x/Process-Data/Triggers.html" class="nav-link" aria-label="简体中文"><!---->简体中文<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><button id="appearance-switch"><svg xmlns="http://www.w3.org/2000/svg" class="icon auto-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="auto icon" style="display:block;"><path d="M512 992C246.92 992 32 777.08 32 512S246.92 32 512 32s480 214.92 480 480-214.92 480-480 480zm0-840c-198.78 0-360 161.22-360 360 0 198.84 161.22 360 360 360s360-161.16 360-360c0-198.78-161.22-360-360-360zm0 660V212c165.72 0 300 134.34 300 300 0 165.72-134.28 300-300 300z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon dark-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="dark icon" style="display:none;"><path d="M524.8 938.667h-4.267a439.893 439.893 0 0 1-313.173-134.4 446.293 446.293 0 0 1-11.093-597.334A432.213 432.213 0 0 1 366.933 90.027a42.667 42.667 0 0 1 45.227 9.386 42.667 42.667 0 0 1 10.24 42.667 358.4 358.4 0 0 0 82.773 375.893 361.387 361.387 0 0 0 376.747 82.774 42.667 42.667 0 0 1 54.187 55.04 433.493 433.493 0 0 1-99.84 154.88 438.613 438.613 0 0 1-311.467 128z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon light-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="light icon" style="display:none;"><path d="M952 552h-80a40 40 0 0 1 0-80h80a40 40 0 0 1 0 80zM801.88 280.08a41 41 0 0 1-57.96-57.96l57.96-58a41.04 41.04 0 0 1 58 58l-58 57.96zM512 752a240 240 0 1 1 0-480 240 240 0 0 1 0 480zm0-560a40 40 0 0 1-40-40V72a40 40 0 0 1 80 0v80a40 40 0 0 1-40 40zm-289.88 88.08-58-57.96a41.04 41.04 0 0 1 58-58l57.96 58a41 41 0 0 1-57.96 57.96zM192 512a40 40 0 0 1-40 40H72a40 40 0 0 1 0-80h80a40 40 0 0 1 40 40zm30.12 231.92a41 41 0 0 1 57.96 57.96l-57.96 58a41.04 41.04 0 0 1-58-58l58-57.96zM512 832a40 40 0 0 1 40 40v80a40 40 0 0 1-80 0v-80a40 40 0 0 1 40-40zm289.88-88.08 58 57.96a41.04 41.04 0 0 1-58 58l-57.96-58a41 41 0 0 1 57.96-57.96z"></path></svg></button></div><div class="nav-item"><a class="repo-link" href="https://github.com/apache/iotdb" target="_blank" rel="noopener noreferrer" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="icon github-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="github icon" style="width:1.25rem;height:1.25rem;vertical-align:middle;"><path d="M511.957 21.333C241.024 21.333 21.333 240.981 21.333 512c0 216.832 140.544 400.725 335.574 465.664 24.49 4.395 32.256-10.07 32.256-23.083 0-11.69.256-44.245 0-85.205-136.448 29.61-164.736-64.64-164.736-64.64-22.315-56.704-54.4-71.765-54.4-71.765-44.587-30.464 3.285-29.824 3.285-29.824 49.195 3.413 75.179 50.517 75.179 50.517 43.776 75.008 114.816 53.333 142.762 40.79 4.523-31.66 17.152-53.377 31.19-65.537-108.971-12.458-223.488-54.485-223.488-242.602 0-53.547 19.114-97.323 50.517-131.67-5.035-12.33-21.93-62.293 4.779-129.834 0 0 41.258-13.184 134.912 50.346a469.803 469.803 0 0 1 122.88-16.554c41.642.213 83.626 5.632 122.88 16.554 93.653-63.488 134.784-50.346 134.784-50.346 26.752 67.541 9.898 117.504 4.864 129.834 31.402 34.347 50.474 78.123 50.474 131.67 0 188.586-114.73 230.016-224.042 242.09 17.578 15.232 33.578 44.672 33.578 90.454v135.85c0 13.142 7.936 27.606 32.854 22.87C862.25 912.597 1002.667 728.747 1002.667 512c0-271.019-219.648-490.667-490.71-490.667z"></path></svg></a></div><!--[--><!----><!--]--><button class="toggle-navbar-button" aria-label="Toggle Navbar" aria-expanded="false" aria-controls="nav-screen"><span class="button-container"><span class="button-top"></span><span class="button-middle"></span><span class="button-bottom"></span></span></button></div></header><!----><!--]--><!----><div class="toggle-sidebar-wrapper"><span class="arrow start"></span></div><aside class="sidebar" id="sidebar"><!--[--><!----><!--]--><ul class="sidebar-links"><li><section class="sidebar-group"><p class="sidebar-heading"><!----><span class="title">IoTDB User Guide (V0.13.x)</span><!----></p><ul class="sidebar-links"></ul></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">IoTDB Introduction</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Quick Start</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Data Concept</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Syntax Conventions</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">API</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Operate Metadata</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Write and Delete Data</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Query Data</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable active"><!----><span class="title">Process Data</span><span class="arrow down"></span></button><ul class="sidebar-links"><li><!--[--><a href="/UserGuide/V0.13.x/Process-Data/UDF-User-Defined-Function.html" class="nav-link sidebar-link sidebar-page" aria-label="UDF (User Defined Function)"><!---->UDF (User Defined Function)<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/UserGuide/V0.13.x/Process-Data/Select-Into.html" class="nav-link sidebar-link sidebar-page" aria-label="Query Write-back (SELECT INTO)"><!---->Query Write-back (SELECT INTO)<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/UserGuide/V0.13.x/Process-Data/Continuous-Query.html" class="nav-link sidebar-link sidebar-page" aria-label="CQ (Continuous Query)"><!---->CQ (Continuous Query)<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html" class="router-link-active router-link-exact-active nav-link active sidebar-link sidebar-page active" aria-label="Triggers"><!---->Triggers<!----></a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#triggers-implementation" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Triggers Implementation"><!---->Triggers Implementation<!----></a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#dependency" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Dependency"><!---->Dependency<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#programming-interfaces" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Programming Interfaces"><!---->Programming Interfaces<!----></a><ul class="sidebar-sub-headers"></ul></li></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#triggers-management" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Triggers Management"><!---->Triggers Management<!----></a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#trigger-states" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Trigger States"><!---->Trigger States<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#register-triggers" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Register Triggers"><!---->Register Triggers<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#drop-triggers" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Drop Triggers"><!---->Drop Triggers<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#start-triggers" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Start Triggers"><!---->Start Triggers<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#stop-triggers" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Stop Triggers"><!---->Stop Triggers<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#show-all-registered-triggers" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Show All Registered Triggers"><!---->Show All Registered Triggers<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#user-authority-management" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="User Authority Management"><!---->User Authority Management<!----></a><ul class="sidebar-sub-headers"></ul></li></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#utilities" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Utilities"><!---->Utilities<!----></a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#windowing-utility" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Windowing Utility"><!---->Windowing Utility<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#sink-utility" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Sink Utility"><!---->Sink Utility<!----></a><ul class="sidebar-sub-headers"></ul></li></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#maven-project-example" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Maven Project Example"><!---->Maven Project Example<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#important-notes-1" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="Important Notes"><!---->Important Notes<!----></a><ul class="sidebar-sub-headers"></ul></li></ul><!--]--></li><li><!--[--><a href="/UserGuide/V0.13.x/Process-Data/Alerting.html" class="nav-link sidebar-link sidebar-page" aria-label="Alerting"><!---->Alerting<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li></ul></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Administration Management</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Maintenance Tools</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Ecosystem Integration</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">UDF Library</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">Reference</span><span class="arrow end"></span></button><!----></section></li></ul><!--[--><!----><!--]--></aside><!--[--><main class="page" id="main-content"><!--[--><!----><nav class="breadcrumb disable"></nav><div class="page-title"><h1><!---->Triggers</h1><div class="page-info"><!----><!----><!----><!----><span class="page-reading-time-info" aria-label="Reading Time"><svg xmlns="http://www.w3.org/2000/svg" class="icon timer-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="timer icon"><path d="M799.387 122.15c4.402-2.978 7.38-7.897 7.38-13.463v-1.165c0-8.933-7.38-16.312-16.312-16.312H256.33c-8.933 0-16.311 7.38-16.311 16.312v1.165c0 5.825 2.977 10.874 7.637 13.592 4.143 194.44 97.22 354.963 220.201 392.763-122.204 37.542-214.893 196.511-220.2 389.397-4.661 5.049-7.638 11.651-7.638 19.03v5.825h566.49v-5.825c0-7.379-2.849-13.981-7.509-18.9-5.049-193.016-97.867-351.985-220.2-389.527 123.24-37.67 216.446-198.453 220.588-392.892zM531.16 450.445v352.632c117.674 1.553 211.787 40.778 211.787 88.676H304.097c0-48.286 95.149-87.382 213.728-88.676V450.445c-93.077-3.107-167.901-81.297-167.901-177.093 0-8.803 6.99-15.793 15.793-15.793 8.803 0 15.794 6.99 15.794 15.793 0 80.261 63.69 145.635 142.01 145.635s142.011-65.374 142.011-145.635c0-8.803 6.99-15.793 15.794-15.793s15.793 6.99 15.793 15.793c0 95.019-73.789 172.82-165.96 177.093z"></path></svg><span>About 13 min</span><meta property="timeRequired" content="PT13M"></span><!----><!----></div><hr></div><div class="toc-place-holder"><aside id="toc"><!--[--><!----><!--]--><div class="toc-header">On This Page<button class="print-button" title="Print"><svg xmlns="http://www.w3.org/2000/svg" class="icon print-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="print icon"><path d="M819.2 364.8h-44.8V128c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v236.8h-44.8C145.067 364.8 96 413.867 96 473.6v192c0 59.733 49.067 108.8 108.8 108.8h44.8V896c0 17.067 14.933 32 32 32h460.8c17.067 0 32-14.933 32-32V774.4h44.8c59.733 0 108.8-49.067 108.8-108.8v-192c0-59.733-49.067-108.8-108.8-108.8zM313.6 160h396.8v204.8H313.6V160zm396.8 704H313.6V620.8h396.8V864zM864 665.6c0 25.6-19.2 44.8-44.8 44.8h-44.8V588.8c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v121.6h-44.8c-25.6 0-44.8-19.2-44.8-44.8v-192c0-25.6 19.2-44.8 44.8-44.8h614.4c25.6 0 44.8 19.2 44.8 44.8v192z"></path></svg></button></div><div class="toc-wrapper"><ul class="toc-list"><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#triggers-implementation" class="router-link-active router-link-exact-active toc-link level2">Triggers Implementation</a></li><ul class="toc-list"><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#dependency" class="router-link-active router-link-exact-active toc-link level3">Dependency</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#programming-interfaces" class="router-link-active router-link-exact-active toc-link level3">Programming Interfaces</a></li><!----><!--]--></ul><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#triggers-management" class="router-link-active router-link-exact-active toc-link level2">Triggers Management</a></li><ul class="toc-list"><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#trigger-states" class="router-link-active router-link-exact-active toc-link level3">Trigger States</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#register-triggers" class="router-link-active router-link-exact-active toc-link level3">Register Triggers</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#drop-triggers" class="router-link-active router-link-exact-active toc-link level3">Drop Triggers</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#start-triggers" class="router-link-active router-link-exact-active toc-link level3">Start Triggers</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#stop-triggers" class="router-link-active router-link-exact-active toc-link level3">Stop Triggers</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#show-all-registered-triggers" class="router-link-active router-link-exact-active toc-link level3">Show All Registered Triggers</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#user-authority-management" class="router-link-active router-link-exact-active toc-link level3">User Authority Management</a></li><!----><!--]--></ul><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#utilities" class="router-link-active router-link-exact-active toc-link level2">Utilities</a></li><ul class="toc-list"><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#windowing-utility" class="router-link-active router-link-exact-active toc-link level3">Windowing Utility</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#sink-utility" class="router-link-active router-link-exact-active toc-link level3">Sink Utility</a></li><!----><!--]--></ul><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#maven-project-example" class="router-link-active router-link-exact-active toc-link level2">Maven Project Example</a></li><!----><!--]--><!--[--><li class="toc-item"><a aria-current="page" href="/UserGuide/V0.13.x/Process-Data/Triggers.html#important-notes-1" class="router-link-active router-link-exact-active toc-link level2">Important Notes</a></li><!----><!--]--></ul></div><!--[--><!----><!--]--></aside></div><!----><div class="theme-hope-content"><!-- |
| |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| |
| --><h1 id="triggers" tabindex="-1"><a class="header-anchor" href="#triggers" aria-hidden="true">#</a> Triggers</h1><p>The trigger provides a mechanism for listening to changes in time series data. With user-defined logic, tasks such as alerting, data cleaning, and data forwarding can be conducted.</p><p>The trigger is implemented based on the reflection mechanism. Users can monitor data changes by implementing the Java interfaces. IoTDB allows users to dynamically register and drop triggers without restarting the server.</p><p>The document will help you learn to define and manage triggers.</p><h2 id="triggers-implementation" tabindex="-1"><a class="header-anchor" href="#triggers-implementation" aria-hidden="true">#</a> Triggers Implementation</h2><h3 id="dependency" tabindex="-1"><a class="header-anchor" href="#dependency" aria-hidden="true">#</a> Dependency</h3><p>You need to implement the trigger by writing a Java class, where the dependency shown below is required. If you use <a href="http://search.maven.org/" target="_blank" rel="noopener noreferrer">Maven<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>, you can search for them directly from the <a href="http://search.maven.org/" target="_blank" rel="noopener noreferrer">Maven repository<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>.</p><div class="language-xml line-numbers-mode" data-ext="xml"><pre class="language-xml"><code><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> |
| <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.apache.iotdb<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> |
| <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>iotdb-server<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> |
| <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>0.13.0-SNAPSHOT<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> |
| <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>scope</span><span class="token punctuation">></span></span>provided<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>scope</span><span class="token punctuation">></span></span> |
| <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Note that the dependency version should be correspondent to the target server version.</p><h3 id="programming-interfaces" tabindex="-1"><a class="header-anchor" href="#programming-interfaces" aria-hidden="true">#</a> Programming Interfaces</h3><p>To implement a trigger, you need to implement the <code>org.apache.iotdb.db.engine.trigger.api.Trigger</code> class.</p><p>This class provides two types of programming interfaces: <strong>life cycle hooks</strong> and <strong>data change listening hooks</strong>. All the interfaces in this class are not required to be implemented. When the interfaces are not implemented, the trigger will not respond to the data changes. You can implement only some of these interfaces according to your needs.</p><p>Descriptions of the interfaces are as followed.</p><h4 id="life-cycle-hooks" tabindex="-1"><a class="header-anchor" href="#life-cycle-hooks" aria-hidden="true">#</a> Life Cycle Hooks</h4><table><thead><tr><th style="text-align:left;">Interface Definition</th><th>Description</th></tr></thead><tbody><tr><td style="text-align:left;"><code>void onCreate(TriggerAttributes attributes) throws Exception</code></td><td>When you use the <code>CREATE TRIGGER</code> statement to register the trigger, the hook will be called. In the life cycle of each instance, the hook will and only will be called once. This hook mainly has the following functions: 1. To parse custom attributes in SQL statements (using <code>TriggerAttributes</code>). 2. To create or apply for resources, such as establishing external links, opening files, etc.</td></tr><tr><td style="text-align:left;"><code>void onDrop() throws Exception</code></td><td>When you use the <code>DROP TRIGGER</code> statement to drop the trigger, the hook will be called. In the life cycle of each instance, the hook will and only will be called once. The main function of this hook is to perform operations such as releasing resources.</td></tr><tr><td style="text-align:left;"><code>void onStart() throws Exception</code></td><td>This hook will be called when you use the <code>START TRIGGER</code> statement to manually start the trigger (whose state should be <code>STOPPED</code>).</td></tr><tr><td style="text-align:left;"><code>void onStop() throws Exception</code></td><td>This hook will be called when you use the <code>STOP TRIGGER</code> statement to manually stop the trigger (whose state should be <code>STARTED</code>).</td></tr></tbody></table><h4 id="data-change-listening-hooks" tabindex="-1"><a class="header-anchor" href="#data-change-listening-hooks" aria-hidden="true">#</a> Data Change Listening Hooks</h4><p>Currently, triggers can only listen for data insertion operations.</p><p>The timing of calling the data change listener hooks is explicitly specified in the <code>CREATE TRIGGER</code> statement rather than at the programming interface level.</p><h5 id="single-point-insertion-listening-hooks" tabindex="-1"><a class="header-anchor" href="#single-point-insertion-listening-hooks" aria-hidden="true">#</a> Single Point Insertion Listening Hooks</h5><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">Integer</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span> timestamp<span class="token punctuation">,</span> <span class="token class-name">Integer</span> value<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token class-name">Long</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span> timestamp<span class="token punctuation">,</span> <span class="token class-name">Long</span> value<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token class-name">Float</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span> timestamp<span class="token punctuation">,</span> <span class="token class-name">Float</span> value<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token class-name">Double</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span> timestamp<span class="token punctuation">,</span> <span class="token class-name">Double</span> value<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token class-name">Boolean</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span> timestamp<span class="token punctuation">,</span> <span class="token class-name">Boolean</span> value<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token class-name">Binary</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span> timestamp<span class="token punctuation">,</span> <span class="token class-name">Binary</span> value<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>For each data insertion in the registered time series, the trigger will call <code>fire</code> as a response. The input parameters <code>timestamp</code> and <code>value</code> are the time and value of the data point inserted this time. You can write any logic to process data in the <code>fire</code> hook.</p><p>Note that currently the return value of the hook is meaningless.</p><h5 id="batch-data-insertion-listening-hooks" tabindex="-1"><a class="header-anchor" href="#batch-data-insertion-listening-hooks" aria-hidden="true">#</a> Batch Data Insertion Listening Hooks</h5><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token keyword">float</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token keyword">float</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token keyword">double</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token keyword">double</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token keyword">boolean</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token keyword">boolean</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| <span class="token class-name">Binary</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token class-name">Binary</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>If you need to use the <code>insertTablet</code> interface or the <code>insertTablets</code> interface of the Session API, you can reduce the overhead of trigger calls by implementing the above batch data insertion listening hooks.</p><p>It is recommended that the behaviors of the batch data insertion listening hooks and the single point insertion listening hooks be consistent. The default implemetation of the listening hook for batch data insertion is as followed.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">default</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span> <span class="token punctuation">{</span> |
| <span class="token keyword">int</span> size <span class="token operator">=</span> timestamps<span class="token punctuation">.</span>length<span class="token punctuation">;</span> |
| <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator"><</span> size<span class="token punctuation">;</span> <span class="token operator">++</span>i<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token function">fire</span><span class="token punctuation">(</span>timestamps<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">,</span> values<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| <span class="token keyword">return</span> values<span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Note that currently the return value of the hook is meaningless.</p><h4 id="important-notes" tabindex="-1"><a class="header-anchor" href="#important-notes" aria-hidden="true">#</a> Important Notes</h4><ul><li>Triggers registered on different time series are difference instances, so you can maintain states in triggers.</li><li>The states maintained by triggers will be cleared after the system stops (unless you persist the data by yourself). The states of the triggers will be default values after the system is restarted.</li><li>All hook calls of a trigger are serialized.</li></ul><h2 id="triggers-management" tabindex="-1"><a class="header-anchor" href="#triggers-management" aria-hidden="true">#</a> Triggers Management</h2><p>You can register, drop, start or stop a trigger instance through SQL statements, and you can also query all registered triggers through SQL statements.</p><h3 id="trigger-states" tabindex="-1"><a class="header-anchor" href="#trigger-states" aria-hidden="true">#</a> Trigger States</h3><p>Triggers have two states: <code>STARTED</code> and <code>STOPPED</code>. You can start or stop a trigger by executing <code>START TRIGGER</code> or <code>STOP TRIGGER</code>.</p><p>When the state of a trigger is <code>STOPPED</code>, it will not respond to the operations on the registered time series (such as inserting a data point), but all status (trigger variables), and registration information will be saved.</p><p>Note that the default state of the triggers registered by the <code>CREATE TRIGGER</code> statement is <code>STARTED</code>.</p><h3 id="register-triggers" tabindex="-1"><a class="header-anchor" href="#register-triggers" aria-hidden="true">#</a> Register Triggers</h3><p>A trigger can only be registered on an existing time series. Only one trigger can be registered for any time series.</p><p>The time series registered with the trigger will be listened to by the trigger. When there is a data change in the time series, the corresponding hook in the trigger will be called.</p><p>Registering a trigger can be carried out as follows:</p><ol><li><p>Implement a complete Trigger class. Assume that the full class name of this class is <code>org.apache.iotdb.db.engine.trigger.example.AlertListener</code>.</p></li><li><p>Pack the project into a JAR package. If you use Maven to manage the project, you can refer to the above Maven project example.</p></li><li><p>Put the JAR package in the directory <code>iotdb-server-0.13.0-SNAPSHOT/ext/trigger</code> (or a subdirectory of <code>iotdb-server-0.13.0-SNAPSHOT/ext/trigger</code>).</p><blockquote><p>You can specify the root path to load the trigger JAR packages by modifying the <code>trigger_root_dir</code> in the configuration file.</p></blockquote></li><li><p>Use the SQL statement to register the trigger. Assume that the name given to the trigger is <code>alert-listener-sg1d1s1</code>.</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> <span class="token keyword">TRIGGER</span> <span class="token identifier"><span class="token punctuation">`</span>alert-listener-sg1d1s1<span class="token punctuation">`</span></span> |
| <span class="token keyword">AFTER</span> <span class="token keyword">INSERT</span> |
| <span class="token keyword">ON</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">.</span>s1 |
| <span class="token keyword">AS</span> <span class="token string">'org.apache.iotdb.db.engine.trigger.example.AlertListener'</span> |
| <span class="token keyword">WITH</span> <span class="token punctuation">(</span> |
| <span class="token string">'lo'</span> <span class="token operator">=</span> <span class="token string">'0'</span><span class="token punctuation">,</span> |
| <span class="token string">'hi'</span> <span class="token operator">=</span> <span class="token string">'100.0'</span> |
| <span class="token punctuation">)</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li></ol><p>The following shows the SQL syntax of registering a trigger.</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> <span class="token keyword">TRIGGER</span> <span class="token operator"><</span><span class="token keyword">TRIGGER</span><span class="token operator">-</span>NAME<span class="token operator">></span> |
| <span class="token punctuation">(</span>BEFORE <span class="token operator">|</span> <span class="token keyword">AFTER</span><span class="token punctuation">)</span> <span class="token keyword">INSERT</span> |
| <span class="token keyword">ON</span> <span class="token operator"><</span><span class="token keyword">FULL</span><span class="token operator">-</span>PATH<span class="token operator">></span> |
| <span class="token keyword">AS</span> <span class="token operator"><</span>CLASSNAME<span class="token operator">></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>You can also set any number of key-value pair attributes for the trigger through the <code>WITH</code> clause:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> <span class="token keyword">TRIGGER</span> <span class="token operator"><</span><span class="token keyword">TRIGGER</span><span class="token operator">-</span>NAME<span class="token operator">></span> |
| <span class="token punctuation">(</span>BEFORE <span class="token operator">|</span> <span class="token keyword">AFTER</span><span class="token punctuation">)</span> <span class="token keyword">INSERT</span> |
| <span class="token keyword">ON</span> <span class="token operator"><</span><span class="token keyword">FULL</span><span class="token operator">-</span>PATH<span class="token operator">></span> |
| <span class="token keyword">AS</span> <span class="token operator"><</span>CLASSNAME<span class="token operator">></span> |
| <span class="token keyword">WITH</span> <span class="token punctuation">(</span> |
| <span class="token operator"><</span><span class="token keyword">KEY</span><span class="token operator">-</span><span class="token number">1</span><span class="token operator">>=</span><span class="token operator"><</span><span class="token keyword">VALUE</span><span class="token operator">-</span><span class="token number">1</span><span class="token operator">></span><span class="token punctuation">,</span> |
| <span class="token operator"><</span><span class="token keyword">KEY</span><span class="token operator">-</span><span class="token number">2</span><span class="token operator">>=</span><span class="token operator"><</span><span class="token keyword">VALUE</span><span class="token operator">-</span><span class="token number">2</span><span class="token operator">></span><span class="token punctuation">,</span> |
| <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> |
| <span class="token punctuation">)</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>TRIGGER-NAME</code> is a globally unique ID of the trigger, which is case sensitive.</p><p>At present, the trigger can listen to all data insertion operations on the time series. The hook can be called <code>BEFORE</code> or <code>AFTER</code> the data is inserted.</p><p><code>FULL-PATH</code> is the name of the time series that the trigger listens to. The path must be a measurement path.</p><p><code>CLASSNAME</code> is the full class name of the trigger.</p><p>Note that <code>CLASSNAME</code>, <code>KEY</code> and <code>VALUE</code> in the attributes need to be quoted in single or double quotes.</p><h3 id="drop-triggers" tabindex="-1"><a class="header-anchor" href="#drop-triggers" aria-hidden="true">#</a> Drop Triggers</h3><p>Triggers will be dropped in the following scenarios:</p><ol><li>When the user executes <code>DELETE TIMESERIES</code>, the triggers registered on the time series will be dropped.</li><li>When the user executes <code>DELETE STORAGE GROUP</code>, the triggers registered under the storage group will be dropped.</li><li>When the user executes the <code>DROP TRIGGER</code> statement.</li></ol><p>The following shows the SQL syntax of dropping a trigger:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">DROP</span> <span class="token keyword">TRIGGER</span> <span class="token operator"><</span><span class="token keyword">TRIGGER</span><span class="token operator">-</span>NAME<span class="token operator">></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>The following is an example of a <code>DROP TRIGGER</code> statement:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">DROP</span> <span class="token keyword">TRIGGER</span> <span class="token identifier"><span class="token punctuation">`</span>alert-listener-sg1d1s1<span class="token punctuation">`</span></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h3 id="start-triggers" tabindex="-1"><a class="header-anchor" href="#start-triggers" aria-hidden="true">#</a> Start Triggers</h3><p>This operation changes the state of the trigger from <code>STOPPED</code> to <code>STARTED</code>, which will make the trigger re-listen to the operations on the registered time series and respond to data changes.</p><p>The following shows the SQL syntax of starting a trigger:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">START</span> <span class="token keyword">TRIGGER</span> <span class="token operator"><</span><span class="token keyword">TRIGGER</span><span class="token operator">-</span>NAME<span class="token operator">></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>The following is an example of a <code>START TRIGGER</code> statement:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">START</span> <span class="token keyword">TRIGGER</span> <span class="token identifier"><span class="token punctuation">`</span>alert-listener-sg1d1s1<span class="token punctuation">`</span></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>Note that the triggers registered by the <code>CREATE TRIGGER</code> statements are <code>STARTED</code> by default.</p><h3 id="stop-triggers" tabindex="-1"><a class="header-anchor" href="#stop-triggers" aria-hidden="true">#</a> Stop Triggers</h3><p>This operation changes the state of the trigger from <code>STARTED</code> to <code>STOPPED</code>. When the status of a trigger is <code>STOPPED</code>, it will not respond to the operations on the registered time series (such as inserting a data point). You can restart a trigger using the <code>START TRIGGER</code> statement.</p><p>The following shows the SQL syntax of stopping a trigger:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code>STOP <span class="token keyword">TRIGGER</span> <span class="token operator"><</span><span class="token keyword">TRIGGER</span><span class="token operator">-</span>NAME<span class="token operator">></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>The following is an example of a <code>STOP TRIGGER</code> statement:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code>STOP <span class="token keyword">TRIGGER</span> <span class="token identifier"><span class="token punctuation">`</span>alert-listener-sg1d1s1<span class="token punctuation">`</span></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h3 id="show-all-registered-triggers" tabindex="-1"><a class="header-anchor" href="#show-all-registered-triggers" aria-hidden="true">#</a> Show All Registered Triggers</h3><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">SHOW</span> TRIGGERS |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h3 id="user-authority-management" tabindex="-1"><a class="header-anchor" href="#user-authority-management" aria-hidden="true">#</a> User Authority Management</h3><p>When a user manages triggers, 4 types of authorities will be involved:</p><ul><li><code>CREATE_TRIGGER</code>: Only users with this authority are allowed to register triggers. This authority is path dependent.</li><li><code>DROP_TRIGGER</code>: Only users with this authority are allowed to drop triggers. This authority is path dependent.</li><li><code>START_TRIGGER</code>: Only users with this authority are allowed to start triggers. This authority is path dependent.</li><li><code>STOP_TRIGGER</code>: Only users with this authority are allowed to stop triggers. This authority is path dependent.</li></ul><p>For more information, refer to <a href="/UserGuide/V0.13.x/Administration-Management/Administration.html" class="">Authority Management Statement</a>.</p><h2 id="utilities" tabindex="-1"><a class="header-anchor" href="#utilities" aria-hidden="true">#</a> Utilities</h2><p>Utility classes provide programming paradigms and execution frameworks for the common requirements, which can simplify part of your work of implementing triggers.</p><h3 id="windowing-utility" tabindex="-1"><a class="header-anchor" href="#windowing-utility" aria-hidden="true">#</a> Windowing Utility</h3><p>The windowing utility can help you define sliding windows and the data processing logic on them. It can construct two types of sliding windows: one has a fixed time interval (<code>SlidingTimeWindowEvaluationHandler</code>), and the other has fixed number of data points (<code>SlidingSizeWindowEvaluationHandler</code>).</p><p>The windowing utility allows you to define a hook (<code>Evaluator</code>) on the window (<code>Window</code>). Whenever a new window is formed, the hook you defined will be called once. You can define any data processing-related logic in the hook. The call of the hook is asynchronous. Therefore, the current thread will not be blocked when the window processing logic is executed.</p><p>It is worth noting that whether it is <code>SlidingTimeWindowEvaluationHandler</code> or <code>SlidingSizeWindowEvaluationHandler</code>, <strong>they can only handle sequences with strictly monotonically increasing timestamps</strong>, and incoming data points that do not meet the requirements will be discarded.</p><p>For the definition of <code>Window</code> and <code>Evaluator</code>, please refer to the <code>org.apache.iotdb.db.utils.windowing.api</code> package.</p><h4 id="slidingsizewindowevaluationhandler" tabindex="-1"><a class="header-anchor" href="#slidingsizewindowevaluationhandler" aria-hidden="true">#</a> SlidingSizeWindowEvaluationHandler</h4><h5 id="window-construction" tabindex="-1"><a class="header-anchor" href="#window-construction" aria-hidden="true">#</a> Window Construction</h5><p>There are two construction methods.</p><p>The first method requires you to provide the type of data points that the window collects, the window size, the sliding step, and a hook (<code>Evaluator</code>).</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">TSDataType</span> dataType <span class="token operator">=</span> <span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">INT32</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">int</span> windowSize <span class="token operator">=</span> <span class="token number">10</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">int</span> slidingStep <span class="token operator">=</span> <span class="token number">5</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">SlidingSizeWindowEvaluationHandler</span> handler <span class="token operator">=</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingSizeWindowEvaluationHandler</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingSizeWindowConfiguration</span><span class="token punctuation">(</span>dataType<span class="token punctuation">,</span> windowSize<span class="token punctuation">,</span> slidingStep<span class="token punctuation">)</span><span class="token punctuation">,</span> |
| window <span class="token operator">-></span> <span class="token punctuation">{</span> |
| <span class="token comment">// do something</span> |
| <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>The second method requires you to provide the type of data points that the window collects, the window size, and a hook (<code>Evaluator</code>). The sliding step is equal to the window size by default.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">TSDataType</span> dataType <span class="token operator">=</span> <span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">INT32</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">int</span> windowSize <span class="token operator">=</span> <span class="token number">10</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">SlidingSizeWindowEvaluationHandler</span> handler <span class="token operator">=</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingSizeWindowEvaluationHandler</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingSizeWindowConfiguration</span><span class="token punctuation">(</span>dataType<span class="token punctuation">,</span> windowSize<span class="token punctuation">)</span><span class="token punctuation">,</span> |
| window <span class="token operator">-></span> <span class="token punctuation">{</span> |
| <span class="token comment">// do something</span> |
| <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>The window size and the sliding step must be positive.</p><h5 id="datapoint-collection" tabindex="-1"><a class="header-anchor" href="#datapoint-collection" aria-hidden="true">#</a> Datapoint Collection</h5><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token keyword">long</span> timestamp <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">int</span> value <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> |
| hander<span class="token punctuation">.</span><span class="token function">collect</span><span class="token punctuation">(</span>timestamp<span class="token punctuation">,</span> value<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Note that the type of the second parameter accepted by the <code>collect</code> method needs to be consistent with the <code>dataType</code> parameter provided during construction.</p><p>In addition, the <code>collect</code> method will only respond to data points whose timestamps are monotonically increasing. If the time stamp of the data point collected by the <code>collect</code> method is less than or equal to the time stamp of the data point collected by the previous <code>collect</code> method call, the data point collected this time will be discarded.</p><p>Also note that the <code>collect</code> method is not thread-safe.</p><h4 id="slidingtimewindowevaluationhandler" tabindex="-1"><a class="header-anchor" href="#slidingtimewindowevaluationhandler" aria-hidden="true">#</a> SlidingTimeWindowEvaluationHandler</h4><h5 id="window-construction-1" tabindex="-1"><a class="header-anchor" href="#window-construction-1" aria-hidden="true">#</a> Window Construction</h5><p>There are two construction methods.</p><p>The first method requires you to provide the type of data points that the window collects, the time interval, the sliding step, and a hook (<code>Evaluator</code>).</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">TSDataType</span> dataType <span class="token operator">=</span> <span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">INT32</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">long</span> timeInterval <span class="token operator">=</span> <span class="token number">1000</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">long</span> slidingStep <span class="token operator">=</span> <span class="token number">500</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">SlidingTimeWindowEvaluationHandler</span> handler <span class="token operator">=</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingTimeWindowEvaluationHandler</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingTimeWindowConfiguration</span><span class="token punctuation">(</span>dataType<span class="token punctuation">,</span> timeInterval<span class="token punctuation">,</span> slidingStep<span class="token punctuation">)</span><span class="token punctuation">,</span> |
| window <span class="token operator">-></span> <span class="token punctuation">{</span> |
| <span class="token comment">// do something</span> |
| <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>The second method requires you to provide the type of data points that the window collects, the time interval, and a hook (<code>Evaluator</code>). The sliding step is equal to the time interval by default.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">TSDataType</span> dataType <span class="token operator">=</span> <span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">INT32</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">long</span> timeInterval <span class="token operator">=</span> <span class="token number">1000</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">SlidingTimeWindowEvaluationHandler</span> handler <span class="token operator">=</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingTimeWindowEvaluationHandler</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingTimeWindowConfiguration</span><span class="token punctuation">(</span>dataType<span class="token punctuation">,</span> timeInterval<span class="token punctuation">)</span><span class="token punctuation">,</span> |
| window <span class="token operator">-></span> <span class="token punctuation">{</span> |
| <span class="token comment">// do something</span> |
| <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>The time interval and the sliding step must be positive.</p><h5 id="datapoint-collection-1" tabindex="-1"><a class="header-anchor" href="#datapoint-collection-1" aria-hidden="true">#</a> Datapoint Collection</h5><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token keyword">long</span> timestamp <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">int</span> value <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> |
| hander<span class="token punctuation">.</span><span class="token function">collect</span><span class="token punctuation">(</span>timestamp<span class="token punctuation">,</span> value<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Note that the type of the second parameter accepted by the <code>collect</code> method needs to be consistent with the <code>dataType</code> parameter provided during construction.</p><p>In addition, the <code>collect</code> method will only respond to data points whose timestamps are monotonically increasing. If the time stamp of the data point collected by the <code>collect</code> method is less than or equal to the time stamp of the data point collected by the previous <code>collect</code> method call, the data point collected this time will be discarded.</p><p>Also note that the <code>collect</code> method is not thread-safe.</p><h4 id="rejection-policy" tabindex="-1"><a class="header-anchor" href="#rejection-policy" aria-hidden="true">#</a> Rejection Policy</h4><p>The execution of window evaluation tasks is asynchronous.</p><p>When asynchronous tasks cannot be consumed by the execution thread pool in time, tasks will accumulate. In extreme cases, the accumulation of asynchronous tasks can cause the system OOM. Therefore, the number of tasks that the window evaluation thread pool allows to accumulate is set to a finite value.</p><p>When the number of accumulated tasks exceeds the limit, the newly submitted tasks will not be able to enter the thread pool for execution. At this time, the system will call the rejection policy hook <code>onRejection</code> that you have implemented in the listening hook (<code>Evaluator</code>) for processing.</p><p>The default behavior of <code>onRejection</code> is as follows.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">default</span> <span class="token keyword">void</span> <span class="token function">onRejection</span><span class="token punctuation">(</span><span class="token class-name">Window</span> window<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token keyword">throw</span> <span class="token keyword">new</span> <span class="token class-name">RejectedExecutionException</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>The way to implement a rejection strategy hook is as follows.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SlidingTimeWindowEvaluationHandler</span> handler <span class="token operator">=</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingTimeWindowEvaluationHandler</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingTimeWindowConfiguration</span><span class="token punctuation">(</span><span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">INT32</span><span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">,</span> |
| <span class="token keyword">new</span> <span class="token class-name">Evaluator</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">evaluate</span><span class="token punctuation">(</span><span class="token class-name">Window</span> window<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token comment">// do something</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">onRejection</span><span class="token punctuation">(</span><span class="token class-name">Window</span> window<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token comment">// do something</span> |
| <span class="token punctuation">}</span> |
| <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="configurable-properties" tabindex="-1"><a class="header-anchor" href="#configurable-properties" aria-hidden="true">#</a> Configurable Properties</h4><h5 id="concurrent-window-evaluation-thread" tabindex="-1"><a class="header-anchor" href="#concurrent-window-evaluation-thread" aria-hidden="true">#</a> concurrent_window_evaluation_thread</h5><p>The number of threads that can be used for evaluating sliding windows. The value is equals to CPU core number by default.</p><h5 id="max-pending-window-evaluation-tasks" tabindex="-1"><a class="header-anchor" href="#max-pending-window-evaluation-tasks" aria-hidden="true">#</a> max_pending_window_evaluation_tasks</h5><p>The maximum number of window evaluation tasks that can be pending for execution. The value is 64 by default.</p><h3 id="sink-utility" tabindex="-1"><a class="header-anchor" href="#sink-utility" aria-hidden="true">#</a> Sink Utility</h3><p>The sink utility provides the ability for triggers to connect to external systems.</p><p>It provides a programming paradigm. Each sink utility contains a <code>Handler</code> for processing data sending, a <code>Configuration</code> for configuring <code>Handler</code>, and an <code>Event</code> for describing the sending data.</p><h4 id="localiotdbsink" tabindex="-1"><a class="header-anchor" href="#localiotdbsink" aria-hidden="true">#</a> LocalIoTDBSink</h4><p><code>LocalIoTDBSink</code> is used to insert data points to the local sequence.</p><p>Before writing data, it is not required that the time series have been created.</p><p><strong>Note</strong>, in the scenario used for triggers, the listening time series and the written target time series should not be in the same storage group.</p><p>Example:</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">String</span> device <span class="token operator">=</span> <span class="token string">"root.alerting"</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span> measurements <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token punctuation">{</span><span class="token string">"local"</span><span class="token punctuation">}</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">TSDataType</span><span class="token punctuation">[</span><span class="token punctuation">]</span> dataTypes <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">TSDataType</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token punctuation">{</span><span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">DOUBLE</span><span class="token punctuation">}</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">LocalIoTDBHandler</span> localIoTDBHandler <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">LocalIoTDBHandler</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| localIoTDBHandler<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">LocalIoTDBConfiguration</span><span class="token punctuation">(</span>device<span class="token punctuation">,</span> measurements<span class="token punctuation">,</span> dataTypes<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token comment">// insert 100 data points</span> |
| <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator"><</span> <span class="token number">100</span><span class="token punctuation">;</span> <span class="token operator">++</span>i<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token keyword">final</span> <span class="token keyword">long</span> timestamp <span class="token operator">=</span> i<span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">double</span> value <span class="token operator">=</span> i<span class="token punctuation">;</span> |
| localIoTDBHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">LocalIoTDBEvent</span><span class="token punctuation">(</span>timestamp<span class="token punctuation">,</span> value<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Note that when you need to insert data points to a time series of type <code>TEXT</code>, you need to use <code>org.apache.iotdb.tsfile.utils.Binary</code>:</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token comment">// insert 100 data points</span> |
| <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator"><</span> <span class="token number">100</span><span class="token punctuation">;</span> <span class="token operator">++</span>i<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token keyword">final</span> <span class="token keyword">long</span> timestamp <span class="token operator">=</span> i<span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">String</span> value <span class="token operator">=</span> <span class="token string">""</span> <span class="token operator">+</span> i<span class="token punctuation">;</span> |
| localIoTDBHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">LocalIoTDBEvent</span><span class="token punctuation">(</span>timestamp<span class="token punctuation">,</span> <span class="token class-name">Binary</span><span class="token punctuation">.</span><span class="token function">valueOf</span><span class="token punctuation">(</span>value<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="mqttsink" tabindex="-1"><a class="header-anchor" href="#mqttsink" aria-hidden="true">#</a> MQTTSink</h4><p>In triggers, you can use <code>MQTTSink</code> to send data points to other IoTDB instances.</p><p>Before sending data, it is not required that the time series have been created.</p><p>Example:</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">String</span> host <span class="token operator">=</span> <span class="token string">"127.0.0.1"</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">int</span> port <span class="token operator">=</span> <span class="token number">1883</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">String</span> username <span class="token operator">=</span> <span class="token string">"root"</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">String</span> password <span class="token operator">=</span> <span class="token string">"root"</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">PartialPath</span> device <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">PartialPath</span><span class="token punctuation">(</span><span class="token string">"root.alerting"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span> measurements <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token punctuation">{</span><span class="token string">"remote"</span><span class="token punctuation">}</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">MQTTHandler</span> mqttHandler <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MQTTHandler</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| mqttHandler<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">MQTTConfiguration</span><span class="token punctuation">(</span>host<span class="token punctuation">,</span> port<span class="token punctuation">,</span> username<span class="token punctuation">,</span> password<span class="token punctuation">,</span> device<span class="token punctuation">,</span> measurements<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">final</span> <span class="token class-name">String</span> topic <span class="token operator">=</span> <span class="token string">"test"</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token class-name">QoS</span> qos <span class="token operator">=</span> <span class="token class-name">QoS</span><span class="token punctuation">.</span><span class="token constant">EXACTLY_ONCE</span><span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">boolean</span> retain <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span> |
| <span class="token comment">// send 100 data points</span> |
| <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator"><</span> <span class="token number">100</span><span class="token punctuation">;</span> <span class="token operator">++</span>i<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token keyword">final</span> <span class="token keyword">long</span> timestamp <span class="token operator">=</span> i<span class="token punctuation">;</span> |
| <span class="token keyword">final</span> <span class="token keyword">double</span> value <span class="token operator">=</span> i<span class="token punctuation">;</span> |
| mqttHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">MQTTEvent</span><span class="token punctuation">(</span>topic<span class="token punctuation">,</span> qos<span class="token punctuation">,</span> retain<span class="token punctuation">,</span> timestamp<span class="token punctuation">,</span> value<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="alertmanagersink" tabindex="-1"><a class="header-anchor" href="#alertmanagersink" aria-hidden="true">#</a> AlertManagerSink</h4><p>In a trigger, you can use <code>AlertManagerSink</code> to send messages to AlertManager。</p><p>You need to specify the endpoint to send alerts of your AlertManager when constructing <code>AlertManagerConfiguration</code></p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">AlertManagerConfiguration</span><span class="token punctuation">(</span><span class="token class-name">String</span> endpoint<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p><code>AlertManagerEvent</code> offers three types of constructors：</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">AlertManagerEvent</span><span class="token punctuation">(</span><span class="token class-name">String</span> alertname<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token class-name">AlertManagerEvent</span><span class="token punctuation">(</span><span class="token class-name">String</span> alertname<span class="token punctuation">,</span> <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">></span></span> extraLabels<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token class-name">AlertManagerEvent</span><span class="token punctuation">(</span><span class="token class-name">String</span> alertname<span class="token punctuation">,</span> <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">></span></span> extraLabels<span class="token punctuation">,</span> <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">></span></span> annotations<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li><code>alertname</code> is a required parameter to identify an <code>alert</code>. The <code>alertname</code> field can be used for grouping and deduplication when the <code>AlertManager</code> sends an alert.</li><li><code>extraLabels</code> is optional. In the backend, it is combined with <code>alertname</code> to form <code>labels</code> to identify an <code>alert</code>, which can be used for grouping and deduplication when <code>AlertManager</code> sends alarms.</li><li><code>annotations</code> is optional, and its value can use Go style template<div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>{{.<label_key>}} |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div>It will be replaced with <code>labels[<label_key>]</code> when the message is finally generated.</li><li><code>labels</code> and <code>annotations</code> will be parsed into json string and sent to <code>AlertManager</code>:</li></ul><div class="language-json line-numbers-mode" data-ext="json"><pre class="language-json"><code><span class="token punctuation">{</span> |
| <span class="token property">"labels"</span><span class="token operator">:</span> <span class="token punctuation">{</span> |
| <span class="token property">"alertname"</span><span class="token operator">:</span> <span class="token string">"<requiredAlertName>"</span><span class="token punctuation">,</span> |
| <span class="token property">"<labelname>"</span><span class="token operator">:</span> <span class="token string">"<labelvalue>"</span><span class="token punctuation">,</span> |
| ... |
| <span class="token punctuation">}</span><span class="token punctuation">,</span> |
| <span class="token property">"annotations"</span><span class="token operator">:</span> <span class="token punctuation">{</span> |
| <span class="token property">"<labelname>"</span><span class="token operator">:</span> <span class="token string">"<labelvalue>"</span><span class="token punctuation">,</span> |
| ... |
| <span class="token punctuation">}</span> |
| <span class="token punctuation">}</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Call the <code>onEvent(AlertManagerEvent event)</code> method of <code>AlertManagerHandler</code> to send an alert.</p><p><strong>Example 1:</strong></p><p>Only pass <code>alertname</code>.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">AlertManagerHandler</span> alertManagerHandler <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">AlertManagerHandler</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| alertManagerHandler<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">AlertManagerConfiguration</span><span class="token punctuation">(</span><span class="token string">"http://127.0.0.1:9093/api/v1/alerts"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">final</span> <span class="token class-name">String</span> alertName <span class="token operator">=</span> <span class="token string">"test0"</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">AlertManagerEvent</span> alertManagerEvent <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">AlertManagerEvent</span><span class="token punctuation">(</span>alertName<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| alertManagerHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span>alertManagerEvent<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><strong>Example 2：</strong></p><p>Pass <code>alertname</code> and <code>extraLabels</code>.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">AlertManagerHandler</span> alertManagerHandler <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">AlertManagerHandler</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| alertManagerHandler<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">AlertManagerConfiguration</span><span class="token punctuation">(</span><span class="token string">"http://127.0.0.1:9093/api/v1/alerts"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">final</span> <span class="token class-name">String</span> alertName <span class="token operator">=</span> <span class="token string">"test1"</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">final</span> <span class="token class-name">HashMap</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">></span></span> extraLabels <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token generics"><span class="token punctuation"><</span><span class="token punctuation">></span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| extraLabels<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"severity"</span><span class="token punctuation">,</span> <span class="token string">"critical"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| extraLabels<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"series"</span><span class="token punctuation">,</span> <span class="token string">"root.ln.wt01.wf01.temperature"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| extraLabels<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"value"</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">.</span><span class="token function">valueOf</span><span class="token punctuation">(</span><span class="token number">100.0</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token class-name">AlertManagerEvent</span> alertManagerEvent <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">AlertManagerEvent</span><span class="token punctuation">(</span>alertName<span class="token punctuation">,</span> extraLabels<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| alertManagerHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span>alertManagerEvent<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><strong>Example 3：</strong></p><p>Pass <code>alertname</code>， <code>extraLabels</code> 和 <code>annotations</code>.</p><p>The final value of the <code>description</code> field will be parsed as <code>test2: root.ln.wt01.wf01.temperature is 100.0</code>.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">AlertManagerHandler</span> alertManagerHandler <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">AlertManagerHandler</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| alertManagerHandler<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">AlertManagerConfiguration</span><span class="token punctuation">(</span><span class="token string">"http://127.0.0.1:9093/api/v1/alerts"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">final</span> <span class="token class-name">String</span> alertName <span class="token operator">=</span> <span class="token string">"test2"</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">final</span> <span class="token class-name">HashMap</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">></span></span> extraLabels <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token generics"><span class="token punctuation"><</span><span class="token punctuation">></span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| extraLabels<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"severity"</span><span class="token punctuation">,</span> <span class="token string">"critical"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| extraLabels<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"series"</span><span class="token punctuation">,</span> <span class="token string">"root.ln.wt01.wf01.temperature"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| extraLabels<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"value"</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">.</span><span class="token function">valueOf</span><span class="token punctuation">(</span><span class="token number">100.0</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">final</span> <span class="token class-name">HashMap</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">></span></span> annotations <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token generics"><span class="token punctuation"><</span><span class="token punctuation">></span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| annotations<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"summary"</span><span class="token punctuation">,</span> <span class="token string">"high temperature"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| annotations<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"description"</span><span class="token punctuation">,</span> <span class="token string">"{{.alertname}}: {{.series}} is {{.value}}"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| alertManagerHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">AlertManagerEvent</span><span class="token punctuation">(</span>alertName<span class="token punctuation">,</span> extraLabels<span class="token punctuation">,</span> annotations<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h2 id="maven-project-example" tabindex="-1"><a class="header-anchor" href="#maven-project-example" aria-hidden="true">#</a> Maven Project Example</h2><p>If you use <a href="http://search.maven.org/" target="_blank" rel="noopener noreferrer">Maven<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>, you can refer to our sample project <strong>trigger-example</strong>.</p><p>You can find it <a href="https://github.com/apache/iotdb/tree/master/example/trigger" target="_blank" rel="noopener noreferrer">here<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>.</p><p>It shows:</p><ul><li>How to use Maven to manage your trigger project</li><li>How to listen to data changes based on the user programming interface</li><li>How to use the windowing utility</li><li>How to use the sink utility</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">package</span> <span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>trigger</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>api<span class="token punctuation">.</span></span><span class="token class-name">Trigger</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>api<span class="token punctuation">.</span></span><span class="token class-name">TriggerAttributes</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>metadata<span class="token punctuation">.</span>path<span class="token punctuation">.</span></span><span class="token class-name">PartialPath</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>sink<span class="token punctuation">.</span>mqtt<span class="token punctuation">.</span></span><span class="token class-name">MQTTConfiguration</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>sink<span class="token punctuation">.</span>mqtt<span class="token punctuation">.</span></span><span class="token class-name">MQTTEvent</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>sink<span class="token punctuation">.</span>mqtt<span class="token punctuation">.</span></span><span class="token class-name">MQTTHandler</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>sink<span class="token punctuation">.</span>local<span class="token punctuation">.</span></span><span class="token class-name">LocalIoTDBConfiguration</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>sink<span class="token punctuation">.</span>local<span class="token punctuation">.</span></span><span class="token class-name">LocalIoTDBEvent</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>engine<span class="token punctuation">.</span>trigger<span class="token punctuation">.</span>sink<span class="token punctuation">.</span>local<span class="token punctuation">.</span></span><span class="token class-name">LocalIoTDBHandler</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>utils<span class="token punctuation">.</span>windowing<span class="token punctuation">.</span>configuration<span class="token punctuation">.</span></span><span class="token class-name">SlidingSizeWindowConfiguration</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>db<span class="token punctuation">.</span>utils<span class="token punctuation">.</span>windowing<span class="token punctuation">.</span>handler<span class="token punctuation">.</span></span><span class="token class-name">SlidingSizeWindowEvaluationHandler</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>tsfile<span class="token punctuation">.</span>file<span class="token punctuation">.</span>metadata<span class="token punctuation">.</span>enums<span class="token punctuation">.</span></span><span class="token class-name">TSDataType</span></span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>fusesource<span class="token punctuation">.</span>mqtt<span class="token punctuation">.</span>client<span class="token punctuation">.</span></span><span class="token class-name">QoS</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>slf4j<span class="token punctuation">.</span></span><span class="token class-name">Logger</span></span><span class="token punctuation">;</span> |
| <span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>slf4j<span class="token punctuation">.</span></span><span class="token class-name">LoggerFactory</span></span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">TriggerExample</span> <span class="token keyword">implements</span> <span class="token class-name">Trigger</span> <span class="token punctuation">{</span> |
| |
| <span class="token keyword">private</span> <span class="token keyword">static</span> <span class="token keyword">final</span> <span class="token class-name">Logger</span> <span class="token constant">LOGGER</span> <span class="token operator">=</span> <span class="token class-name">LoggerFactory</span><span class="token punctuation">.</span><span class="token function">getLogger</span><span class="token punctuation">(</span><span class="token class-name">TriggerExample</span><span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">private</span> <span class="token keyword">static</span> <span class="token keyword">final</span> <span class="token class-name">String</span> <span class="token constant">TARGET_DEVICE</span> <span class="token operator">=</span> <span class="token string">"root.alerting"</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">private</span> <span class="token keyword">final</span> <span class="token class-name">LocalIoTDBHandler</span> localIoTDBHandler <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">LocalIoTDBHandler</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">private</span> <span class="token keyword">final</span> <span class="token class-name">MQTTHandler</span> mqttHandler <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MQTTHandler</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">private</span> <span class="token class-name">SlidingSizeWindowEvaluationHandler</span> windowEvaluationHandler<span class="token punctuation">;</span> |
| |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">onCreate</span><span class="token punctuation">(</span><span class="token class-name">TriggerAttributes</span> attributes<span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span> <span class="token punctuation">{</span> |
| <span class="token constant">LOGGER</span><span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"onCreate(TriggerAttributes attributes)"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">double</span> lo <span class="token operator">=</span> attributes<span class="token punctuation">.</span><span class="token function">getDouble</span><span class="token punctuation">(</span><span class="token string">"lo"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">double</span> hi <span class="token operator">=</span> attributes<span class="token punctuation">.</span><span class="token function">getDouble</span><span class="token punctuation">(</span><span class="token string">"hi"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token function">openSinkHandlers</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| windowEvaluationHandler <span class="token operator">=</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingSizeWindowEvaluationHandler</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">SlidingSizeWindowConfiguration</span><span class="token punctuation">(</span><span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">DOUBLE</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">)</span><span class="token punctuation">,</span> |
| window <span class="token operator">-></span> <span class="token punctuation">{</span> |
| <span class="token keyword">double</span> avg <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> |
| <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator"><</span> window<span class="token punctuation">.</span><span class="token function">size</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token operator">++</span>i<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| avg <span class="token operator">+=</span> window<span class="token punctuation">.</span><span class="token function">getDouble</span><span class="token punctuation">(</span>i<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| avg <span class="token operator">/=</span> window<span class="token punctuation">.</span><span class="token function">size</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">if</span> <span class="token punctuation">(</span>avg <span class="token operator"><</span> lo <span class="token operator">||</span> hi <span class="token operator"><</span> avg<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| localIoTDBHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">LocalIoTDBEvent</span><span class="token punctuation">(</span>window<span class="token punctuation">.</span><span class="token function">getTime</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">,</span> avg<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| mqttHandler<span class="token punctuation">.</span><span class="token function">onEvent</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">MQTTEvent</span><span class="token punctuation">(</span><span class="token string">"test"</span><span class="token punctuation">,</span> <span class="token class-name">QoS</span><span class="token punctuation">.</span><span class="token constant">EXACTLY_ONCE</span><span class="token punctuation">,</span> <span class="token boolean">false</span><span class="token punctuation">,</span> window<span class="token punctuation">.</span><span class="token function">getTime</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">,</span> avg<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">onDrop</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span> <span class="token punctuation">{</span> |
| <span class="token constant">LOGGER</span><span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"onDrop()"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token function">closeSinkHandlers</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">onStart</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span> <span class="token punctuation">{</span> |
| <span class="token constant">LOGGER</span><span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"onStart()"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token function">openSinkHandlers</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">onStop</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span> <span class="token punctuation">{</span> |
| <span class="token constant">LOGGER</span><span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"onStop()"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token function">closeSinkHandlers</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token class-name">Double</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span> timestamp<span class="token punctuation">,</span> <span class="token class-name">Double</span> value<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| windowEvaluationHandler<span class="token punctuation">.</span><span class="token function">collect</span><span class="token punctuation">(</span>timestamp<span class="token punctuation">,</span> value<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">return</span> value<span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token annotation punctuation">@Override</span> |
| <span class="token keyword">public</span> <span class="token keyword">double</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token function">fire</span><span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">,</span> <span class="token keyword">double</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator"><</span> timestamps<span class="token punctuation">.</span>length<span class="token punctuation">;</span> <span class="token operator">++</span>i<span class="token punctuation">)</span> <span class="token punctuation">{</span> |
| windowEvaluationHandler<span class="token punctuation">.</span><span class="token function">collect</span><span class="token punctuation">(</span>timestamps<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">,</span> values<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| <span class="token keyword">return</span> values<span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token keyword">private</span> <span class="token keyword">void</span> <span class="token function">openSinkHandlers</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span> <span class="token punctuation">{</span> |
| localIoTDBHandler<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">LocalIoTDBConfiguration</span><span class="token punctuation">(</span> |
| <span class="token constant">TARGET_DEVICE</span><span class="token punctuation">,</span> <span class="token keyword">new</span> <span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">{</span><span class="token string">"local"</span><span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token keyword">new</span> <span class="token class-name">TSDataType</span><span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">{</span><span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">DOUBLE</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| mqttHandler<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span> |
| <span class="token keyword">new</span> <span class="token class-name">MQTTConfiguration</span><span class="token punctuation">(</span> |
| <span class="token string">"127.0.0.1"</span><span class="token punctuation">,</span> |
| <span class="token number">1883</span><span class="token punctuation">,</span> |
| <span class="token string">"root"</span><span class="token punctuation">,</span> |
| <span class="token string">"root"</span><span class="token punctuation">,</span> |
| <span class="token keyword">new</span> <span class="token class-name">PartialPath</span><span class="token punctuation">(</span><span class="token constant">TARGET_DEVICE</span><span class="token punctuation">)</span><span class="token punctuation">,</span> |
| <span class="token keyword">new</span> <span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">{</span><span class="token string">"remote"</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| |
| <span class="token keyword">private</span> <span class="token keyword">void</span> <span class="token function">closeSinkHandlers</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">throws</span> <span class="token class-name">Exception</span> <span class="token punctuation">{</span> |
| localIoTDBHandler<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| mqttHandler<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| <span class="token punctuation">}</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>You can try this trigger by following the steps below:</p><ul><li><p>Enable MQTT service by modifying <code>iotdb-engine.properties</code></p><div class="language-properties line-numbers-mode" data-ext="properties"><pre class="language-properties"><code><span class="token comment"># whether to enable the mqtt service.</span> |
| <span class="token key attr-name">enable_mqtt_service</span><span class="token punctuation">=</span><span class="token value attr-value">true</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>Start the IoTDB server</p></li><li><p>Create time series via cli</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> TIMESERIES root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">.</span>s1 <span class="token keyword">WITH</span> DATATYPE<span class="token operator">=</span><span class="token keyword">DOUBLE</span><span class="token punctuation">,</span> ENCODING<span class="token operator">=</span>PLAIN<span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div></li><li><p>Place the JAR (<code>trigger-example-0.13.0-SNAPSHOT.jar</code>) of <strong>trigger-example</strong> in the directory <code>iotdb-server-0.13.0-SNAPSHOT/ext/trigger</code> (or in a subdirectory of <code>iotdb-server-0.13.0-SNAPSHOT/ext/trigger</code>)</p><blockquote><p>You can specify the root path to load the trigger JAR package by modifying the <code>trigger_root_dir</code> in the configuration file.</p></blockquote></li><li><p>Use the SQL statement to register the trigger, assuming that the name given to the trigger is <code>window-avg-alerter</code></p></li><li><p>Use the <code>CREATE TRIGGER</code> statement to register the trigger via cli</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> <span class="token keyword">TRIGGER</span> <span class="token identifier"><span class="token punctuation">`</span>window-avg-alerter<span class="token punctuation">`</span></span> |
| <span class="token keyword">AFTER</span> <span class="token keyword">INSERT</span> |
| <span class="token keyword">ON</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">.</span>s1 |
| <span class="token keyword">AS</span> <span class="token string">'org.apache.iotdb.trigger.TriggerExample'</span> |
| <span class="token keyword">WITH</span> <span class="token punctuation">(</span> |
| <span class="token string">'lo'</span> <span class="token operator">=</span> <span class="token string">'0'</span><span class="token punctuation">,</span> |
| <span class="token string">'hi'</span> <span class="token operator">=</span> <span class="token string">'10.0'</span> |
| <span class="token punctuation">)</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>Use cli to insert test data</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">,</span> <span class="token number">8</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">6</span><span class="token punctuation">,</span> <span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">7</span><span class="token punctuation">,</span> <span class="token number">12</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">8</span><span class="token punctuation">,</span> <span class="token number">14</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">9</span><span class="token punctuation">,</span> <span class="token number">16</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">(</span><span class="token keyword">timestamp</span><span class="token punctuation">,</span> s1<span class="token punctuation">)</span> <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">,</span> <span class="token number">18</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>Use cli to query data to verify the behavior of the trigger</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>alerting<span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div></li><li><p>Under normal circumstances, the following results should be shown</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code>IoTDB<span class="token operator">></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>alerting<span class="token punctuation">;</span> |
| <span class="token operator">+</span><span class="token comment">-----------------------------+--------------------+-------------------+</span> |
| <span class="token operator">|</span> <span class="token keyword">Time</span><span class="token operator">|</span>root<span class="token punctuation">.</span>alerting<span class="token punctuation">.</span>remote<span class="token operator">|</span>root<span class="token punctuation">.</span>alerting<span class="token punctuation">.</span><span class="token keyword">local</span><span class="token operator">|</span> |
| <span class="token operator">+</span><span class="token comment">-----------------------------+--------------------+-------------------+</span> |
| <span class="token operator">|</span><span class="token number">1970</span><span class="token operator">-</span><span class="token number">01</span><span class="token operator">-</span><span class="token number">01</span>T08:<span class="token number">00</span>:<span class="token number">00.006</span><span class="token operator">+</span><span class="token number">08</span>:<span class="token number">00</span><span class="token operator">|</span> <span class="token number">14.0</span><span class="token operator">|</span> <span class="token number">14.0</span><span class="token operator">|</span> |
| <span class="token operator">+</span><span class="token comment">-----------------------------+--------------------+-------------------+</span> |
| Total line number <span class="token operator">=</span> <span class="token number">1</span> |
| It costs <span class="token number">0.006</span>s |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li></ul><p>That's all, please enjoy it 😄</p><h2 id="important-notes-1" tabindex="-1"><a class="header-anchor" href="#important-notes-1" aria-hidden="true">#</a> Important Notes</h2><ul><li><p>The trigger is implemented based on the reflection mechanism. Triggers can be dynamically registered and dropped without restarting the server.</p></li><li><p>It is best not to have classes with the same full class name but different function implementations in different JAR packages under <code>trigger_root_dir</code>. For example: the triggers <code>trigger1</code> and <code>trigger2</code> correspond to <code>trigger1.jar</code> and <code>trigger2.jar</code> respectively. If both JAR packages contain a <code>org.apache.iotdb.db.engine.trigger.example.AlertListener</code> class, when this class is used by a <code>CREATE TRIGGER</code> statement, the system will randomly load the class in one of the JAR packages, which may lead to inconsistent trigger behaviors and other problems.</p></li><li><p>Version management of trigger classes with the same full class name. Triggers with the same full class name but different versions (logic) are not allowed to register in the system.</p><p>Related question: IoTDB pre-registered 10 <code>org.apache.iotdb.db.engine.trigger.example.AlertListener</code> trigger instances and DBA updated the implementation and corresponding JAR package of <code>org.apache.iotdb.db.engine.trigger.example.AlertListener</code>. Is it possible to drop only 5 of the instances and replace them with 5 updated trigger instances?</p><p>Answer: No. Only by dropping all the 10 pre-registered triggers can you register the updated triggers. If all the original triggers are not dropped, the newly registered triggers with the same full class name will behave in the same way as the existing triggers.</p></li></ul></div><!----><footer class="page-meta"><div class="meta-item edit-link"><a href="https://github.com/apache/iotdb/edit/rel/0.13/docs/UserGuide/Process-Data/Triggers.md" rel="noopener noreferrer" target="_blank" aria-label="Found Error? Edit this page on GitHub" class="nav-link label"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon edit-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="edit icon"><path d="M430.818 653.65a60.46 60.46 0 0 1-50.96-93.281l71.69-114.012 7.773-10.365L816.038 80.138A60.46 60.46 0 0 1 859.225 62a60.46 60.46 0 0 1 43.186 18.138l43.186 43.186a60.46 60.46 0 0 1 0 86.373L588.879 565.55l-8.637 8.637-117.466 68.234a60.46 60.46 0 0 1-31.958 11.229z"></path><path d="M728.802 962H252.891A190.883 190.883 0 0 1 62.008 771.98V296.934a190.883 190.883 0 0 1 190.883-192.61h267.754a60.46 60.46 0 0 1 0 120.92H252.891a69.962 69.962 0 0 0-69.098 69.099V771.98a69.962 69.962 0 0 0 69.098 69.098h475.911A69.962 69.962 0 0 0 797.9 771.98V503.363a60.46 60.46 0 1 1 120.922 0V771.98A190.883 190.883 0 0 1 728.802 962z"></path></svg><!--]-->Found Error? Edit this page on GitHub<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="meta-item git-info"><!----><!----></div></footer><nav class="page-nav"><a href="/UserGuide/V0.13.x/Process-Data/Continuous-Query.html" class="nav-link prev" aria-label="CQ (Continuous Query)"><div class="hint"><span class="arrow start"></span>Prev</div><div class="link"><!---->CQ (Continuous Query)</div></a><a href="/UserGuide/V0.13.x/Process-Data/Alerting.html" class="nav-link next" aria-label="Alerting"><div class="hint">Next<span class="arrow end"></span></div><div class="link">Alerting<!----></div></a></nav><!----><!----><!--]--></main><!--]--><footer style="padding-bottom:2rem;"><span id="doc-version" style="display:none;">rel/0.13</span><p style="text-align:center;color:#909399;font-size:12px;margin:0 30px;">Copyright © 2023 The Apache Software Foundation.<br> Apache and the Apache feather logo are trademarks of The Apache Software Foundation</p><p style="text-align:center;margin-top:10px;color:#909399;font-size:12px;margin:0 30px;"><strong>Have a question?</strong> Connect with us on QQ, WeChat, or Slack. <a href="https://github.com/apache/iotdb/issues/1995">Join the community</a> now.</p><p style="text-align:center;margin-top:10px;color:#909399;font-size:12px;margin:0 30px;"> We use <a href="https://analytics.google.com">Google Analytics</a> to collect anonymous, aggregated usage information. </p></footer></div><!--]--><!--]--><!----><!--]--></div> |
| <script type="module" src="/assets/app-f2ec2f8e.js" defer></script> |
| </body> |
| </html> |
