| import{_ as s,C as a,O as d,P as h,ah as c,Q as r,U as e,ai as n,ae as u,aW as o}from"./framework-62ad666a.js";const l={},p=o('<h1 id="虚拟存储组" tabindex="-1"><a class="header-anchor" href="#虚拟存储组" aria-hidden="true">#</a> 虚拟存储组</h1><h2 id="背景" tabindex="-1"><a class="header-anchor" href="#背景" aria-hidden="true">#</a> 背景</h2><p>存储组由用户显示指定,使用语句"SET STORAGE GROUP TO"来指定存储组,每一个存储组有一个对应的 StorageGroupProcessor</p><p>为了确保最终一致性,每一个存储组有一个数据插入锁(排它锁)来同步每一次插入操作。 所以服务端数据写入的并行度为存储组的数量。</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,存储组数量)</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)。 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(称为虚拟存储组),将同步粒度从存储组级别改为虚拟存储组粒度。</p>',9),g={href:"http://root.sg",target:"_blank",rel:"noopener noreferrer"},_={href:"http://root.sg",target:"_blank",rel:"noopener noreferrer"},m=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存储组下虚拟存储组的数量:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>virtual_storage_group_num |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>推荐值为[virtual storage group number] = [CPU core number] / [user-defined storage group number]</p>`,4);function f(x,b){const t=a("ExternalLinkIcon"),i=a("RouterLink");return d(),h("div",null,[c(` |
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| `),p,r("p",null,[e('更具体的,我们使用哈希将设备分到不同的虚拟存储组下,例如: 对于一个名为"root.sg.d"的设备(假设其存储组为"'),r("a",g,[e("root.sg"),n(t)]),e('"),它属于的虚拟存储组为"'),r("a",_,[e("root.sg"),n(t)]),e('.[hash("root.sg.d") mod num_of_virtual_storage_group]"')]),m,r("p",null,[e("参考"),n(i,{to:"/zh/UserGuide/V0.13.x/Reference/Config-Manual.html"},{default:u(()=>[e("配置手册")]),_:1}),e("以获取更多信息。")])])}const v=s(l,[["render",f],["__file","VirtualStorageGroup.html.vue"]]);export{v as default}; |