import{_ as s,r,o as d,c,a as h,d as a,e,b as n,w as l,f as o}from"./app-JXXlW6H7.js";const u={},p=o('<h2 id="背景" tabindex="-1"><a class="header-anchor" href="#背景" aria-hidden="true">#</a> 背景</h2><p>Database 由用户显示指定，使用语句&quot;CREATE DATABASE&quot;来指定 database，每一个 database 有多个对应的 data region</p><p>为了确保最终一致性，每一个 data region 有一个数据插入锁（排它锁）来同步每一次插入操作。<br> 所以服务端数据写入的并行度为 data region的数量。</p><h2 id="问题" tabindex="-1"><a class="header-anchor" href="#问题" aria-hidden="true">#</a> 问题</h2><p>从背景中可知，IoTDB数据写入的并行度为 max(客户端数量，服务端数据写入的并行度)，也就是max(客户端数量，data region 数量)</p><p>在生产实践中，存储组的概念往往与特定真实世界实体相关（例如工厂，地点，国家等）。<br> 因此存储组的数量可能会比较小，这会导致IoTDB写入并行度不足。即使我们开再多的客户端写入线程，也无法走出这种困境。</p><h2 id="解决方案" tabindex="-1"><a class="header-anchor" href="#解决方案" aria-hidden="true">#</a> 解决方案</h2><p>我们的方案是将一个存储组下的设备分为若干个设备组（称为 data region），将同步粒度从存储组级别改为 data region 粒度。</p>',8),g=a("br",null,null,-1),_={href:"http://root.sg",target:"_blank",rel:"noopener noreferrer"},m={href:"http://root.sg",target:"_blank",rel:"noopener noreferrer"},f=o(`<h2 id="使用方法" tabindex="-1"><a class="header-anchor" href="#使用方法" aria-hidden="true">#</a> 使用方法</h2><p>通过改变如下配置来设置每一个 database 下 data region 的数量：</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>data_region_num
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>推荐值为[data region number] = [CPU core number] / [user-defined database number]</p>`,4);function b(x,S){const t=r("ExternalLinkIcon"),i=r("RouterLink");return d(),c("div",null,[h(`

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`),p,a("p",null,[e("更具体的，我们使用哈希将设备分到不同的 data region 下，例如："),g,e(' 对于一个名为"root.sg.d"的设备（假设其存储组为"'),a("a",_,[e("root.sg"),n(t)]),e('"），它属于的 data region 为"'),a("a",m,[e("root.sg"),n(t)]),e('.[hash("root.sg.d") mod num_of_data_region]"')]),f,a("p",null,[e("参考"),n(i,{to:"/zh/UserGuide/V1.1.x/Reference/DataNode-Config-Manual.html"},{default:l(()=>[e("配置手册")]),_:1}),e("以获取更多信息。")])])}const A=s(u,[["render",b],["__file","DataRegion.html.vue"]]);export{A as default};