https://xinqilin.github.io/tags/hikaricp/ Recent content in HikariCP on Bill.Lin's Notes Hugo zh-tw Mon, 15 Jan 2024 00:00:00 +0800 https://xinqilin.github.io/post/backend/hikaricp-tuning/ Mon, 15 Jan 2024 00:00:00 +0800 https://xinqilin.github.io/post/backend/hikaricp-tuning/ <h2 id="為什麼需要連線池">為什麼需要連線池</h2> <p>每次建立一條 MySQL 連線涉及：</p> <ol> <li>TCP 三向交握</li> <li>MySQL 認證協議（握手、登入封包）</li> <li>SSL 協商（若啟用）</li> </ol> <p>單次耗時 ~5–30ms，在高並發場景下，每個請求都新建連線會讓延遲成為瓶頸。連線池預先建立固定數量的連線並重複使用，消除這段開銷。</p> <p>另一個角度：<strong>MySQL Server 端的連線數有上限</strong>（<code>max_connections</code>，預設 151）。連線池讓多個應用執行緒共享少量資料庫連線。</p> <hr> <h2 id="hikaricp-核心參數">HikariCP 核心參數</h2> <div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code><span class="lnt"> 1 </span><span class="lnt"> 2 </span><span class="lnt"> 3 </span><span class="lnt"> 4 </span><span class="lnt"> 5 </span><span class="lnt"> 6 </span><span class="lnt"> 7 </span><span class="lnt"> 8 </span><span class="lnt"> 9 </span><span class="lnt">10 </span></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-yaml" data-lang="yaml"><span class="line"><span class="cl"><span class="nt">spring</span><span class="p">:</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">datasource</span><span class="p">:</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">hikari</span><span class="p">:</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">maximum-pool-size</span><span class="p">:</span><span class="w"> </span><span class="m">10</span><span class="w"> </span><span class="c"># 連線池最大連線數</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">minimum-idle</span><span class="p">:</span><span class="w"> </span><span class="m">5</span><span class="w"> </span><span class="c"># 最少保持的閒置連線數</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">connection-timeout</span><span class="p">:</span><span class="w"> </span><span class="m">30000</span><span class="w"> </span><span class="c"># 向池請求連線的最長等待時間（ms），超過拋出例外</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">idle-timeout</span><span class="p">:</span><span class="w"> </span><span class="m">600000</span><span class="w"> </span><span class="c"># 閒置連線在池中存活的最長時間（ms），10 分鐘</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">max-lifetime</span><span class="p">:</span><span class="w"> </span><span class="m">1800000</span><span class="w"> </span><span class="c"># 連線在池中存活的最長時間（ms），30 分鐘</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">leak-detection-threshold</span><span class="p">:</span><span class="w"> </span><span class="m">60000</span><span class="w"> </span><span class="c"># 連線被借出後超過此時間未歸還，印出警告（ms）</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">pool-name</span><span class="p">:</span><span class="w"> </span><span class="l">HikariPool-Main</span><span class="w"> </span></span></span></code></pre></td></tr></table> </div> </div><hr> <h2 id="maximumpoolsize-公式">maximumPoolSize 公式</h2> <p>HikariCP 官方推薦公式（基於 PostgreSQL 基準測試，MySQL 也適用）：</p>