| import{_ as t,O as e,P as n,ah as l,aW as d}from"./framework-e4340ccd.js";const a={},i=d(`<h1 id="background" tabindex="-1"><a class="header-anchor" href="#background" aria-hidden="true">#</a> Background</h1><p>When IoTDB service is started, metadata information is organized by loading log file <code>mlog.bin</code> and the results are held in memory for a long time. As metadata continues to grow, memory continues to grow. In order to support the controllable fluctuation in the massive metadata scenario, we provide a metadata storage type based on rocksDB.</p><h1 id="usage" tabindex="-1"><a class="header-anchor" href="#usage" aria-hidden="true">#</a> Usage</h1><p>Firstly, you should package <strong>schema-engine-rocksdb</strong> by the following command:</p><div class="language-bash line-numbers-mode" data-ext="sh"><pre class="language-bash"><code>mvn clean package <span class="token parameter variable">-pl</span> schema-engine-rocksdb <span class="token parameter variable">-am</span> <span class="token parameter variable">-DskipTests</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>After that, you can get a <strong>conf</strong> directory and a <strong>lib</strong> directory in schema-engine-rocksdb/target/schema-engine-rocksdb. Copy the file in the conf directory to the conf directory of server, and copy the files in the lib directory to the lib directory of server.</p><p>Then, open the <strong>iotdb-datanode.properties</strong> in the conf directory of server, and set the <code>schema_engine_mode</code> to Rocksdb_based. Restart the IoTDB, the system will use <code>RSchemaRegion</code> to manage the metadata.</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>#################### |
| ### Schema Engine Configuration |
| #################### |
| # Choose the mode of schema engine. The value could be Memory,Schema_File and Rocksdb_based. If the provided value doesn't match any pre-defined value, Memory mode will be used as default. |
| # Datatype: string |
| schema_engine_mode=Rocksdb_based |
| |
| </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>When rocksdb is specified as the metadata storage type, configuration parameters of rocksDB are open to the public as file. You can modify the configuration file <code>schema-rocksdb.properties</code> to adjust parameters according to your own requirements, such as block cache. If there is no special requirement, use the default value.</p><h1 id="function-support" tabindex="-1"><a class="header-anchor" href="#function-support" aria-hidden="true">#</a> Function Support</h1><p>The module is still being improved, and some functions are not supported at the moment. The function modules are supported as follows:</p><table><thead><tr><th style="text-align:left;">function</th><th style="text-align:right;">support</th></tr></thead><tbody><tr><td style="text-align:left;">timeseries addition and deletion</td><td style="text-align:right;">yes</td></tr><tr><td style="text-align:left;">query the wildcard path(* and **)</td><td style="text-align:right;">yes</td></tr><tr><td style="text-align:left;">tag addition and deletion</td><td style="text-align:right;">yes</td></tr><tr><td style="text-align:left;">aligned timeseries</td><td style="text-align:right;">yes</td></tr><tr><td style="text-align:left;">wildcard node name(*)</td><td style="text-align:right;">no</td></tr><tr><td style="text-align:left;">meta template</td><td style="text-align:right;">no</td></tr><tr><td style="text-align:left;">tag index</td><td style="text-align:right;">no</td></tr><tr><td style="text-align:left;">continuous query</td><td style="text-align:right;">no</td></tr></tbody></table><h1 id="appendix-interface-support" tabindex="-1"><a class="header-anchor" href="#appendix-interface-support" aria-hidden="true">#</a> Appendix: Interface support</h1><p>The external interface, that is, the client can sense, related SQL is not supported;</p><p>The internal interface, that is, the invocation logic of other modules within the service, has no direct dependence on the external SQL;</p><table><thead><tr><th style="text-align:left;">interface</th><th style="text-align:right;">type</th><th style="text-align:center;">support</th><th style="text-align:center;">comment</th></tr></thead><tbody><tr><td style="text-align:left;">createTimeseries</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">createAlignedTimeSeries</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">showTimeseries</td><td style="text-align:right;">external</td><td style="text-align:center;">part of the support</td><td style="text-align:center;">not support LATEST</td></tr><tr><td style="text-align:left;">changeAlias</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">upsertTagsAndAttributes</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">addAttributes</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">addTags</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">dropTagsOrAttributes</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">setTagsOrAttributesValue</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">renameTagOrAttributeKey</td><td style="text-align:right;">external</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">*template</td><td style="text-align:right;">external</td><td style="text-align:center;">no</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">*trigger</td><td style="text-align:right;">external</td><td style="text-align:center;">no</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">deleteSchemaRegion</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">autoCreateDeviceMNode</td><td style="text-align:right;">internal</td><td style="text-align:center;">no</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">isPathExist</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getAllTimeseriesCount</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getDevicesNum</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getNodesCountInGivenLevel</td><td style="text-align:right;">internal</td><td style="text-align:center;">conditional support</td><td style="text-align:center;">path does not support wildcard</td></tr><tr><td style="text-align:left;">getMeasurementCountGroupByLevel</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getNodesListInGivenLevel</td><td style="text-align:right;">internal</td><td style="text-align:center;">conditional support</td><td style="text-align:center;">path does not support wildcard</td></tr><tr><td style="text-align:left;">getChildNodePathInNextLevel</td><td style="text-align:right;">internal</td><td style="text-align:center;">conditional support</td><td style="text-align:center;">path does not support wildcard</td></tr><tr><td style="text-align:left;">getChildNodeNameInNextLevel</td><td style="text-align:right;">internal</td><td style="text-align:center;">conditional support</td><td style="text-align:center;">path does not support wildcard</td></tr><tr><td style="text-align:left;">getBelongedDevices</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getMatchedDevices</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getMeasurementPaths</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getMeasurementPathsWithAlias</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getAllMeasurementByDevicePath</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getDeviceNode</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getMeasurementMNodes</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr><tr><td style="text-align:left;">getSeriesSchemasAndReadLockDevice</td><td style="text-align:right;">internal</td><td style="text-align:center;">yes</td><td style="text-align:center;"></td></tr></tbody></table>`,16);function r(s,o){return e(),n("div",null,[l(` |
| |
| 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. |
| |
| `),i])}const c=t(a,[["render",r],["__file","SchemaRegion-rocksdb.html.vue"]]);export{c as default}; |
