https://blog.zhangjt.fun/tags/tidb/Recent content in TiDB on DBA学习笔记Hugozh-cn281304173@qq.com (张天师)281304173@qq.com (张天师)This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Tue, 20 Oct 2026 17:21:57 +0800https://blog.zhangjt.fun/tidb-high-cpu-usage/Tue, 24 May 2022 16:11:36 +0800281304173@qq.com (张天师)https://blog.zhangjt.fun/tidb-high-cpu-usage/<h2 id="背景" class="headerLink"> <a href="#%e8%83%8c%e6%99%af" class="header-mark"></a>1. 背景</h2><ul> <li>TiDB Server两个节点CPU使用率都比较高 <figure><a class="lightgallery" href="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/cpu-usage-nodes.svg" title="TiDB Server 两个节点 CPU 使用率" data-thumbnail="/images/posts/tidb-high-cpu-usage/cpu-usage-nodes.svg"> <img loading="lazy" src="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/cpu-usage-nodes.svg" srcset="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/cpu-usage-nodes.svg, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/cpu-usage-nodes.svg 1.5x, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/cpu-usage-nodes.svg 2x" sizes="auto" alt="TiDB Server 两个节点 CPU 使用率"> </a></figure></li> <li>查看QPS指标，可以看到14点到19点之间是基本没有流量的 <figure><a class="lightgallery" href="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/qps-metrics.svg" title="QPS 指标，14 点到 19 点基本无流量" data-thumbnail="/images/posts/tidb-high-cpu-usage/qps-metrics.svg"> <img loading="lazy" src="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/qps-metrics.svg" srcset="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/qps-metrics.svg, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/qps-metrics.svg 1.5x, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/qps-metrics.svg 2x" sizes="auto" alt="QPS 指标，14 点到 19 点基本无流量"> </a></figure></li> <li>登陆机器可以发现，有很多连接其实已经失效，但是还残留服务器上： <figure><a class="lightgallery" href="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/stale-connections.svg" title="服务器上残留的失效连接" data-thumbnail="/images/posts/tidb-high-cpu-usage/stale-connections.svg"> <img loading="lazy" src="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/stale-connections.svg" srcset="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/stale-connections.svg, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/stale-connections.svg 1.5x, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/stale-connections.svg 2x" sizes="auto" alt="服务器上残留的失效连接"> </a></figure></li> <li>怀疑Server负载高和这些诡异的SQL有关系，即便没有释放，也没办法KILL，但是还是占用了一个核的CPU <figure><a class="lightgallery" href="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/2022-05-29-mxWOpSfh5PwAsbL.png" title="20220529204849" data-thumbnail="/images/posts/tidb-high-cpu-usage/2022-05-29-mxWOpSfh5PwAsbL.png"> <img loading="lazy" src="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/2022-05-29-mxWOpSfh5PwAsbL.png" srcset="https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/2022-05-29-mxWOpSfh5PwAsbL.png, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/2022-05-29-mxWOpSfh5PwAsbL.png 1.5x, https://blog.zhangjt.fun/images/posts/tidb-high-cpu-usage/2022-05-29-mxWOpSfh5PwAsbL.png 2x" sizes="auto" alt="20220529204849"> </a></figure> <ul> <li><a href="https://github.com/pingcap/tidb/pull/29212" target="_blank" rel="noopener noreferrer">https://github.com/pingcap/tidb/pull/29212</a></li> <li><a href="https://github.com/pingcap/tidb/issues/24031" target="_blank" rel="noopener noreferrer">https://github.com/pingcap/tidb/issues/24031</a></li> </ul> </li> </ul> <h2 id="解决方案" class="headerLink"> <a href="#%e8%a7%a3%e5%86%b3%e6%96%b9%e6%a1%88" class="header-mark"></a>2. 解决方案</h2><ol> <li> <p>将流量转移到其他机器，可选途径有：</p>