http://blog.chuckchan.top/tags/influx/ Recent content in Influx on Hugo -- gohugo.io zh-cn © 2026 Chuck Chan Tue, 25 Jun 2024 00:00:00 +0000 http://blog.chuckchan.top/posts/middleware/influx/influx%E5%88%9D%E5%AD%A6/ Tue, 25 Jun 2024 00:00:00 +0000 http://blog.chuckchan.top/posts/middleware/influx/influx%E5%88%9D%E5%AD%A6/ <h1 class="relative group">1. introduce <div id="1-introduce" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#1-introduce" aria-label="锚点">#</a> </span> </h1> <p>InfluxDB是一个用于存储和分析时间序列数据的开源数据库。 主要特性有：</p> <ul> <li>内置HTTP接口，使用方便</li> <li>数据可以打标记，这样查询可以很灵活</li> <li>类SQL的查询语句</li> <li>安装管理很简单，并且读写数据很高效</li> <li>能够实时查询，数据在写入时被索引后就能够被立即查出</li> <li>&hellip;</li> </ul> <h1 class="relative group">2. concept <div id="2-concept" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#2-concept" aria-label="锚点">#</a> </span> </h1> <div class="highlight-wrapper"><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-shell" data-lang="shell"><span style="display:flex;"><span>name: census </span></span><span style="display:flex;"><span>-———————————— </span></span><span style="display:flex;"><span>time butterflies honeybees location scientist </span></span><span style="display:flex;"><span>2015-08-18T00:00:00Z <span style="color:#ae81ff">12</span> <span style="color:#ae81ff">23</span> <span style="color:#ae81ff">1</span> langstroth </span></span><span style="display:flex;"><span>2015-08-18T00:00:00Z <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">30</span> <span style="color:#ae81ff">1</span> perpetua </span></span><span style="display:flex;"><span>2015-08-18T00:06:00Z <span style="color:#ae81ff">11</span> <span style="color:#ae81ff">28</span> <span style="color:#ae81ff">1</span> langstroth </span></span><span style="display:flex;"><span>2015-08-18T00:06:00Z <span style="color:#ae81ff">3</span> <span style="color:#ae81ff">28</span> <span style="color:#ae81ff">1</span> perpetua </span></span><span style="display:flex;"><span>2015-08-18T05:54:00Z <span style="color:#ae81ff">2</span> <span style="color:#ae81ff">11</span> <span style="color:#ae81ff">2</span> langstroth </span></span><span style="display:flex;"><span>2015-08-18T06:00:00Z <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">10</span> <span style="color:#ae81ff">2</span> langstroth </span></span><span style="display:flex;"><span>2015-08-18T06:06:00Z <span style="color:#ae81ff">8</span> <span style="color:#ae81ff">23</span> <span style="color:#ae81ff">2</span> perpetua </span></span><span style="display:flex;"><span>2015-08-18T06:12:00Z <span style="color:#ae81ff">7</span> <span style="color:#ae81ff">22</span> <span style="color:#ae81ff">2</span> perpetua</span></span></code></pre></div></div> <p>其中census是<code>measurement</code>，butterflies和honeybees是<code>field key</code>，location和scientist是<code>tag key</code>。</p> <ul> <li>measurement可以理解为表名，这里的measurement为census，可以表示为统计表。</li> <li>field为列，butterflies<code>和</code>honeybees 都是列，称为fields，fields由field key和field value组成。field key(<code>butterflies</code>和<code>honeybees</code>)都是字符串，他们存储元数据；field key <code>butterflies</code>告诉我们蝴蝶的计数从12到7；field key <code>honeybees</code>告诉我们蜜蜂的计数从23变到22。field value就是你的数据，它们可以是字符串、浮点数、整数、布尔值，因为InfluxDB是时间序列数据库，所以field value总是和时间戳相关联。field是InfluxDB数据结构所必需的一部分——在InfluxDB中不能没有field。还要注意，field是没有索引的。如果使用field value作为过滤条件来查询，则必须扫描其他条件匹配后的所有值。因此，这些查询相对于tag上的查询（下文会介绍tag的查询）性能会低很多。 一般来说，字段不应包含常用来查询的元数据。</li> <li>样本数据中的最后两列（<code>location</code>和<code>scientist</code>）就是tag。 tag由tag key和tag value组成。tag key和tag value都作为字符串存储，并记录在元数据中。示例数据中的tag key是<code>location</code>和<code>scientist</code>。 <code>location</code>有两个tag value：<code>1</code>和<code>2</code>。<code>scientist</code>还有两个tag value：<code>langstroth</code>和<code>perpetua</code>。</li> <li>series是共同retention policy，measurement和tag set的集合</li> <li>point简单地理解为时间轴上的一个数据点，即一行数据。</li> </ul> <h1 class="relative group">3. grammar <div id="3-grammar" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#3-grammar" aria-label="锚点">#</a> </span> </h1> <p>读取数据 -&gt; InfluxQL的<code>select</code>语句来自于SQL中的<code>select</code>形式：</p>