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<div class="art_desc mt10" style="margin:10px 5px;padding:10px;color:rgb(51,51,51);border-left-width:3px;border-left-style:solid;border-left-color:rgb(59,176,219);font-size:14px;background:rgb(246,251,255);"><div style="font-family:tahoma, arial, 'Microsoft YaHei';margin:0px;padding:0px;"><p style="background-color:rgb(255,255,255);"><span style="font-weight:700;">MySQL中的日志包括</span>：錯誤日志、二進制日志、通用查詢日志、慢查詢日志等等。這里主要介紹下比較常用的兩個功能：通用查詢日志和慢查詢日志。</p><p style="background-color:rgb(255,255,255);"><span style="font-weight:700;">1）通用查詢日志</span>：記錄建立的客戶端連接和執行的語句。</p><p style="background-color:rgb(255,255,255);"><span style="font-weight:700;">2）慢查詢日志</span>：記錄所有執行時間超過long_query_time秒的所有查詢或者不使用索引的查詢</p><p style="background-color:rgb(255,255,255);"><span style="font-family:'Courier New';font-size:18px;color:rgb(0,0,102);background-color:rgb(255,255,255);">MySQL日志文件系統的組成</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> a、</span><a href="http://blog.csdn.net/leshami/article/details/39759849" rel="nofollow" style="font-family:'Courier New';background-color:rgb(255,255,255);">錯誤日志</a><span style="font-family:'Courier New';background-color:rgb(255,255,255);">：記錄啟動、運行或停止mysqld時出現的問題。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> <strong> b</strong>、</span><a href="http://blog.csdn.net/leshami/article/details/39779225" rel="nofollow" style="font-family:'Courier New';background-color:rgb(255,255,255);">通用日志</a><span style="font-family:'Courier New';background-color:rgb(255,255,255);">：記錄建立的客戶端連接和執行的語句。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> c、更新日志：記錄更改數據的語句。該日志在MySQL 5.1中已不再使用。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> <strong>d</strong>、</span><a href="http://blog.csdn.net/leshami/article/details/39801867" rel="nofollow" style="font-family:'Courier New';background-color:rgb(255,255,255);">二進制日志</a><span style="font-family:'Courier New';background-color:rgb(255,255,255);">：記錄所有更改數據的語句。還用於復制。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> <strong>e</strong>、</span><a href="http://write.blog.csdn.net/postedit/39829605" rel="nofollow" style="font-family:'Courier New';background-color:rgb(255,255,255);">慢查詢日志</a><span style="font-family:'Courier New';background-color:rgb(255,255,255);">：記錄所有執行時間超過long_query_time秒的所有查詢或不使用索引的查詢。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> f、Innodb日志：innodb redo log</span><br></p><p style="background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 缺省情況下，所有日志創建於mysqld數據目錄中。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 可以通過刷新日志，來強制mysqld來關閉和重新打開日志文件（或者在某些情況下切換到一個新的日志）。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 當你執行一個FLUSH LOGS語句或執行mysqladmin flush-logs或mysqladmin refresh時，則日志被老化。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 對於存在MySQL復制的情形下，從復制服務器將維護更多日志文件，被稱為接替日志。</span><br></span></p></div><div style="margin:0px;padding:0px;"><span style="font-family:'Microsoft YaHei';"><span style="background-color:rgb(255,255,255);">同大多數關系型數據庫一樣，日志文件是MySQL數據庫的重要組成部分。MySQL有幾種不同的日志文件，通常包括錯誤日志文件，二進制日志，通用日志，慢查詢日志，等等。這些日志可以幫助我們定位mysqld內部發生的事件，數據庫性能故障，記錄數據的變更歷史，用戶恢復數據庫等等。</span>今天我們要講的是如何分析和查詢mysql慢日志（主要影響程序調用和前端數據呈現）。</span></div><div style="margin:0px;padding:0px;"><br></div><div style="font-family:tahoma, arial, 'Microsoft YaHei';margin:0px;padding:0px;">mysql slow log 是用來記錄執行時間較長(超過long_query_time秒)的sql的一種日志工具</div></div><div class="lbd clearfix" style="margin:0px auto;padding:0px;width:700px;text-align:center;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;line-height:21px;"><span class="jbTestPos"></span></div><div style="margin:0px auto;padding:0px;width:700px;text-align:left;line-height:25.2px;clear:both;"><h3 style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:12pt;color:rgb(34,34,34);margin-top:0px;margin-bottom:0px;padding:0px;">啟用 slow log<br></h3><div style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;color:rgb(34,34,34);margin:0px;padding:0px;line-height:25.2px;">有兩種啟用方式:</div><span style="color:#222222;font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;">1, 在my.cnf 里 通過 log-slow-queries[=file_name]</span><div style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;color:rgb(34,34,34);margin:0px;padding:0px;line-height:25.2px;"></div><div style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;color:rgb(34,34,34);margin:0px;padding:0px;line-height:25.2px;">2, 在mysqld進程啟動時,指定--log-slow-queries[=file_name]選項</div><h3 style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:12pt;color:rgb(34,34,34);margin-top:0px;margin-bottom:0px;padding:0px;">比較的五款常用工具<br></h3><p style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;"><span style="color:#ff0000;">mysqldumpslow</span><span style="color:#222222;">, mysqlsla, myprofi, mysql-explain-slow-log, mysqllogfilter</span></p><p><span style="color:#222222;"><strong><span style="font-family:'Microsoft YaHei';font-size:16px;">開源的MySQL慢日志查詢監控工具</span></strong></span></p><p><span style="font-family:'Microsoft YaHei';font-size:14px;"><span style="color:rgb(34,34,34);background-color:rgb(255,255,255);">pmm server、Navicat、mysqltop（天兔</span><span style="line-height:42px;text-align:center;background-color:rgb(255,255,255);"><span style="color:#000000;">Lepus</span></span><span style="color:rgb(34,34,34);background-color:rgb(255,255,255);">）、</span><span style="color:rgb(204,0,0);line-height:20.02px;background-color:rgb(255,255,255);">Box</span><span style="color:rgb(51,51,51);line-height:20.02px;background-color:rgb(255,255,255);"> </span></span><span style="color:rgb(204,0,0);line-height:20.02px;background-color:rgb(255,255,255);"><span style="font-family:'Microsoft YaHei';font-size:14px;">Anemometer、explain、</span></span><span style="color:rgb(51,51,51);line-height:37.7143px;font-family:'Microsoft YaHei';font-size:14px;background-color:rgb(255,255,255);"><strong>pt-query-digest</strong></span></p><p style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;color:rgb(34,34,34);"><span style="font-family:'Courier New';font-size:18px;color:rgb(0,0,102);background-color:rgb(255,255,255);">慢查詢日志<br></span><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 慢查詢日志是將mysql服務器中影響數據庫性能的相關SQL語句記錄到日志文件，通過對這些特殊的SQL語句分析，改進以達到提高數據庫性能的目的。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 通過使用--slow_query_log[={0|1}]選項來啟用慢查詢日志。所有執行時間超過long_query_time秒的SQL語句都會被記錄到慢查詢日志。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 缺省情況下hostname-slow.log為慢查詢日志文件安名，存放到數據目錄，同時缺省情況下未開啟慢查詢日志。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 缺省情況下數據庫相關管理型SQL(比如OPTIMIZE TABLE、ANALYZE TABLE和ALTER TABLE)不會被記錄到日志。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 對於管理型SQL可以通過--log-slow-admin-statements開啟記錄管理型慢SQL。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> mysqld在語句執行完並且所有鎖釋放后記入慢查詢日志。記錄順序可以與執行順序不相同。獲得初使表鎖定的時間不算作執行時間。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> </span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 可以使用mysqldumpslow命令獲得日志中顯示的查詢摘要來處理慢查詢日志。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> 用查詢緩存處理的查詢不加到慢查詢日志中，表有零行或一行而不能從索引中受益的查詢也不寫入慢查詢日志。</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> MySQL服務器按以下順序記錄SQL是否寫入到慢查詢日志</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> a. The query must either not be an administrative statement, or --log-slow-adminstatements must have been specified.</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> b. The query must have taken at least long_query_time seconds, or log_queries_not_using_indexes must be enabled and the query used no indexes for row lookups.</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> c. The query must have examined at least min_examined_row_limit rows.</span><br style="font-family:'Courier New';background-color:rgb(255,255,255);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"> d. The query must not be suppressed according to the log_throttle_queries_not_using_indexes setting.</span></p><p style="font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;color:rgb(34,34,34);"><span style="font-family:'Courier New';background-color:rgb(255,255,255);"></span></p><p style="border-width:0px;margin-bottom:8px;list-style:none;text-indent:2em;color:rgb(51,51,51);font-family:Simsun;font-size:14px;line-height:28px;background-color:rgb(249,249,249);"><a href="https://www.2cto.com/database/MySQL/" rel="nofollow" class="keylink" style="color:rgb(31,58,135);">mysql</a>dumpslow是mysql自帶的用來分析慢查詢的工具，當然不止這一種工具，還有percona-toolkit是percona公司出的一組命令行工具的集合，用來執行各種通過手工執行非常復雜和麻煩的mysql相關任務，包含以下內容：</p><p style="border-width:0px;margin-bottom:8px;list-style:none;text-indent:2em;color:rgb(51,51,51);font-family:Simsun;font-size:14px;line-height:28px;background-color:rgb(249,249,249);">檢查master和slave數據一致性/記錄有效的歸檔/服務器信息匯總/分析和統計日志,為了省事這塊使用mysqldumpslow命令做分析。</p><p style="border-width:0px;margin-bottom:8px;list-style:none;text-indent:2em;color:rgb(51,51,51);font-family:Simsun;font-size:14px;line-height:28px;background-color:rgb(249,249,249);">需要開啟mysql的慢查詢日志，否則無法進行統計分析，開啟mysql慢查詢日志需要在mysql的配置文件中進行如下配置：</p><div style="border-width:0px;padding:0px;margin:0px;list-style:none;color:rgb(51,51,51);font-family:Simsun;font-size:14px;line-height:28px;background-color:rgb(249,249,249);"><div class="syntaxhighlighter bash" style="border-width:0px;padding:0px;margin:1em 0px;list-style:none;width:613px;font-size:1em;background-color:#FFFFFF;"><table border="0" cellpadding="0" cellspacing="0" style="list-style:none;width:613px;border:0px;padding:0px;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;background:none;"><tbody style="float:none;height:auto;line-height:1.1em;margin:0px;padding:0px;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;background:none;"><tr style="list-style:none;border-top-width:0px;padding:0px;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;background:none;"><td class="gutter" style="list-style:none;border:0px;padding:0px;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;width:auto;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;color:rgb(175,175,175);background:none;"><div class="line number1 index0 alt2" style="list-style:none;border-width:0px 3px 0px 0px;padding:0px .5em 0px 1em;margin:0px;border-right-style:solid;border-right-color:rgb(108,226,108);float:none;height:auto;line-height:1.1em;text-align:right;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;white-space:pre;background-image:none;">1</div><div class="line number2 index1 alt1" style="list-style:none;border-width:0px 3px 0px 0px;padding:0px .5em 0px 1em;margin:0px;border-right-style:solid;border-right-color:rgb(108,226,108);float:none;height:auto;line-height:1.1em;text-align:right;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;white-space:pre;background-image:none;">2</div><div class="line number3 index2 alt2" style="list-style:none;border-width:0px 3px 0px 0px;padding:0px .5em 0px 1em;margin:0px;border-right-style:solid;border-right-color:rgb(108,226,108);float:none;height:auto;line-height:1.1em;text-align:right;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;white-space:pre;background-image:none;">3</div></td><td class="code" style="list-style:none;width:581px;border:0px;padding:0px;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;background:none;"><div class="container" style="list-style:none;border:0px;padding:0px;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;background:none;"><div class="line number1 index0 alt2" style="list-style:none;border:0px;padding:0px 1em;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;white-space:pre;background-image:none;"><code class="bash plain" style="border:0px;float:none;height:auto;line-height:1.1em;margin:0px;padding:0px;vertical-align:baseline;width:auto;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;color:#000000;background:none;">slow_query_log=1</code><code class="bash comments" style="border:0px;float:none;height:auto;line-height:1.1em;margin:0px;padding:0px;vertical-align:baseline;width:auto;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;color:rgb(0,130,0);background:none;">#定義超過1秒的查詢計數到變量Slow_queries</code></div><div class="line number2 index1 alt1" style="list-style:none;border:0px;padding:0px 1em;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;white-space:pre;background-image:none;"><code class="bash plain" style="border:0px;float:none;height:auto;line-height:1.1em;margin:0px;padding:0px;vertical-align:baseline;width:auto;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;color:#000000;background:none;">slow-query-log-</code><code class="bash functions" style="border:0px;float:none;height:auto;line-height:1.1em;margin:0px;padding:0px;vertical-align:baseline;width:auto;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;color:rgb(255,20,147);background:none;">file</code><code class="bash plain" style="border:0px;float:none;height:auto;line-height:1.1em;margin:0px;padding:0px;vertical-align:baseline;width:auto;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;color:#000000;background:none;">=mysql-slow.log</code></div><div class="line number3 index2 alt2" style="list-style:none;border:0px;padding:0px 1em;margin:0px;float:none;height:auto;line-height:1.1em;vertical-align:baseline;width:auto;font-size:1em;min-height:auto;white-space:pre;background-image:none;"><code class="bash plain" style="border:0px;float:none;height:auto;line-height:1.1em;margin:0px;padding:0px;vertical-align:baseline;width:auto;font-family:Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace;font-size:1em;min-height:auto;color:#000000;background:none;">long_query_time=1</code></div></div></td></tr></tbody></table></div></div><br><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.1 簡介</strong></p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">開啟慢查詢日志，可以讓MySQL記錄下查詢超過指定時間的語句，通過定位分析性能的瓶頸，才能更好的優化數據庫系統的性能。</p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.2 登錄數據庫查看</strong></p><div class="jb51code" style="margin:0px;padding:0px;line-height:25.2px;font-size:14px;width:660px;clear:both;text-align:left;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';background-color:rgb(255,255,255);"><div><div id="highlighter_606116" class="syntaxhighlighter bash"><div class="toolbar"><span><a href="#" class="toolbar_item command_help help">?</a></span></div><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="gutter"><div class="line number1 index0 alt2">1</div></td><td class="code"><div class="container"><div class="line number1 index0 alt2"><code class="bash plain">[root@localhost lib]</code><code class="bash comments"># mysql –uroot</code></div></div></td></tr></tbody></table></div></div></div><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">因為沒有設置設置密碼，有密碼的在 mysql –uroot –p 接密碼</p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.2.1 進入MySql 查詢是否開了慢查詢</strong></p><div class="jb51code" style="margin:0px;padding:0px;line-height:25.2px;font-size:14px;width:660px;clear:both;text-align:left;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';background-color:rgb(255,255,255);"><pre><code class="language-sql hljs"><ol class="hljs-ln" style="width:647px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">mysql> <span class="hljs-keyword"><span class="hljs-keyword">show</span></span> <span class="hljs-keyword"><span class="hljs-keyword">variables</span></span> <span class="hljs-keyword"><span class="hljs-keyword">like</span></span> <span class="hljs-string"><span class="hljs-string">'slow_query%'</span></span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">+<span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| Variable_name | Value |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| slow_query_log | OFF |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| slow_query_log_file | /application/mysql/data/localhost-slow.log |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">2 rows in </span><span class="hljs-keyword"><span class="hljs-comment">set</span></span><span class="hljs-comment"> (</span><span class="hljs-number"><span class="hljs-comment">0.00</span></span><span class="hljs-comment"> sec)</span></div></div></li></ol></code><div class="hljs-button signin" data-title="登錄后復制" onclick="hljs.signin(event)"></div></pre></div><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">參數說明：</p><ol style="margin-bottom:0px;margin-left:25px;padding-top:.3em;padding-bottom:.3em;line-height:25px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;text-align:left;background-color:rgb(255,255,255);"><li style="margin:0px;padding:0px;list-style:disc;">slow_query_log 慢查詢開啟狀態 OFF 未開啟 ON 為開啟</li><li style="margin:0px;padding:0px;list-style:disc;">slow_query_log_file 慢查詢日志存放的位置（這個目錄需要MySQL的運行帳號的可寫權限，一般設置為MySQL的數據存放目錄）</li></ol><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.2.2 查看慢查詢超時時間</strong></p><div class="jb51code" style="margin:0px;padding:0px;line-height:25.2px;font-size:14px;width:660px;clear:both;text-align:left;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';background-color:rgb(255,255,255);"><pre><code class="language-sql hljs"><ol class="hljs-ln"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">mysql> <span class="hljs-keyword"><span class="hljs-keyword">show</span></span> <span class="hljs-keyword"><span class="hljs-keyword">variables</span></span> <span class="hljs-keyword"><span class="hljs-keyword">like</span></span> <span class="hljs-string"><span class="hljs-string">'long%'</span></span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">+<span class="hljs-comment"><span class="hljs-comment">-----------------+-----------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| Variable_name | Value |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">-----------------+-----------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| long_query_time | 10.000000 |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">-----------------+-----------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">1 row in </span><span class="hljs-keyword"><span class="hljs-comment">set</span></span><span class="hljs-comment"> (</span><span class="hljs-number"><span class="hljs-comment">0.00</span></span><span class="hljs-comment"> sec)</span></div></div></li></ol></code><div class="hljs-button signin" data-title="登錄后復制" onclick="hljs.signin(event)"></div></pre></div><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">long_query_time 查詢超過多少秒才記錄 默認10秒 修改為1秒</p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.3 修改方法1：（不推薦）</strong></p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">方法一：優點臨時開啟慢查詢，不需要重啟數據庫 缺點：MySql 重啟慢查詢失效</p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">推薦：根據業務需求，建議使用第二種，臨時可以用第一種</p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">默認情況下slow_query_log的值為OFF，表示慢查詢日志是禁用的，可以通過設置slow_query_log的值來開啟，如下所示：：是否開啟慢查詢日志，1表示開啟，0表示關閉。</p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.3.1 查看是否開啟慢查詢</strong></p><div class="jb51code" style="margin:0px;padding:0px;line-height:25.2px;font-size:14px;width:660px;clear:both;text-align:left;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';background-color:rgb(255,255,255);"><pre><code class="language-sql hljs"><ol class="hljs-ln" style="width:647px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">mysql> <span class="hljs-keyword"><span class="hljs-keyword">show</span></span> <span class="hljs-keyword"><span class="hljs-keyword">variables</span></span> <span class="hljs-keyword"><span class="hljs-keyword">like</span></span> <span class="hljs-string"><span class="hljs-string">'%slow_query_log%'</span></span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">+<span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| Variable_name | Value |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| slow_query_log | OFF |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| slow_query_log_file | /application/mysql/data/localhost-slow.log |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">2 rows in </span><span class="hljs-keyword"><span class="hljs-comment">set</span></span><span class="hljs-comment"> (</span><span class="hljs-number"><span class="hljs-comment">0.01</span></span><span class="hljs-comment"> sec)</span></div></div></li></ol></code><div class="hljs-button signin" data-title="登錄后復制" onclick="hljs.signin(event)"></div></pre></div><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">輸入 語句修改（重啟后失效，建議在/etc/my.cnf中修改永久生效）</p><div class="jb51code" style="margin:0px;padding:0px;line-height:25.2px;font-size:14px;width:660px;clear:both;text-align:left;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';background-color:rgb(255,255,255);"><pre><code class="language-sql hljs"><ol class="hljs-ln"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">mysql> <span class="hljs-keyword"><span class="hljs-keyword">set</span></span> <span class="hljs-keyword"><span class="hljs-keyword">global</span></span> slow_query_log=<span class="hljs-number"><span class="hljs-number">1</span></span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">Query OK, 0 rows affected (0.11 sec)</div></div></li></ol></code><div class="hljs-button signin" data-title="登錄后復制" onclick="hljs.signin(event)"></div></pre></div><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.3.2 再次查看</strong></p><div class="jb51code" style="margin:0px;padding:0px;line-height:25.2px;font-size:14px;width:660px;clear:both;text-align:left;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';background-color:rgb(255,255,255);"><pre><code class="language-sql hljs"><ol class="hljs-ln" style="width:647px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">mysql> <span class="hljs-keyword"><span class="hljs-keyword">show</span></span> <span class="hljs-keyword"><span class="hljs-keyword">variables</span></span> <span class="hljs-keyword"><span class="hljs-keyword">like</span></span> <span class="hljs-string"><span class="hljs-string">'%slow_query_log%'</span></span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">+<span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| Variable_name | Value |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| slow_query_log | ON |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">| slow_query_log_file | /application/mysql/data/localhost-slow.log |</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">+</span><span class="hljs-comment"><span class="hljs-comment">---------------------+--------------------------------------------+</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"> </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">2 rows in </span><span class="hljs-keyword"><span class="hljs-comment">set</span></span><span class="hljs-comment"> (</span><span class="hljs-number"><span class="hljs-comment">0.00</span></span><span class="hljs-comment"> sec)</span></div></div></li></ol></code><div class="hljs-button signin" data-title="登錄后復制" onclick="hljs.signin(event)"></div></pre></div><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);"><strong>1.4 修改方法2：（推薦）</strong></p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">修改 MySql 慢查詢，好多人不知道my.cnf 路徑，可以用 find 查找</p><p style="margin-bottom:0px;padding-top:5px;padding-bottom:5px;font-size:14px;line-height:30px;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';text-align:left;background-color:rgb(255,255,255);">備注：我的MySQL 是編譯的 路徑為 /etc/my.cnf （一般都是這里）</p><div class="jb51code" style="margin:0px;padding:0px;line-height:25.2px;font-size:14px;width:660px;clear:both;text-align:left;color:rgb(34,34,34);font-family:tahoma, arial, 'Microsoft YaHei';background-color:rgb(255,255,255);"><pre><code class="language-perl hljs">[root@localhost <span class="hljs-keyword"><span class="hljs-keyword">log</span></span>]<span class="hljs-comment"><span class="hljs-comment"># find / -type f -name "my.cnf"</span></span>
/application/mysql-5.5.51/mysql-test/suite/rpl/my.cnf
/application/mysql-5.5.51/mysql-test/suite/federated/my.cnf
/application/mysql-5.5.51/mysql-5.5.51-linux2.6-x86_64/mysql-test/suite/rpl/my.cnf
/application/mysql-5.5.51/mysql-5.5.51-linux2.6-x86_64/mysql-test/suite/federated/my.cnf
/etc/my.cnf ###（一般都是這里）
1.4.1.1 修改
|
1
|
[root@localhost log]
# vim /etc/my.cnf
|
找到 [mysqld] 下面添加
slow_query_log =1
slow_query_log_file=/application/mysql/data/localhost-slow.log
long_query_time = 1
參數說明：
- slow_query_log 慢查詢開啟狀態 1 為開啟
- slow_query_log_file 慢查詢日志存放的位置
- long_query_time 查詢超過多少秒才記錄 默認10秒 修改為1秒
修改完重啟MySQL
1.5 查看、測試
1.5.1.1 插入一條測試慢查詢
-
mysql>
select
sleep(
2);
-
-
+
----------+
-
-
| sleep(2) |
-
-
+
----------+
-
-
| 0 |
-
-
+
----------+
-
-
1 row in
set
(
2.00
sec)
1.5.1.2 查看慢查詢日志
|
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|
[root@localhost data]
# cat /application/mysql/data/localhost-slow.log
/application/mysql/bin/mysqld
, Version: 5.5.51-log (MySQL Community Server (GPL)). started with:
Tcp port: 3306 Unix socket:
/tmp/mysql
.sock
Time Id Command Argument
/application/mysql/bin/mysqld
, Version: 5.5.51-log (MySQL Community Server (GPL)). started with:
Tcp port: 3306 Unix socket:
/tmp/mysql
.sock
Time Id Command Argument
/application/mysql/bin/mysqld
, Version: 5.5.51-log (MySQL Community Server (GPL)). started with:
Tcp port: 3306 Unix socket:
/tmp/mysql
.sock
Time Id Command Argument
# Time: 170605 6:37:00
# User@Host: root[root] @ localhost []
# Query_time: 2.000835 Lock_time: 0.000000 Rows_sent: 1 Rows_examined: 0
SET timestamp=1496615820;
select
sleep
(2);
|
1.5.1.3 通過MySQL命令查看有多少慢查詢
-
mysql>
show
global
status
like
'%Slow_queries%';
-
-
+
---------------+-------+
-
-
| Variable_name | Value |
-
-
+
---------------+-------+
-
-
| Slow_queries | 1 |
-
-
+
---------------+-------+
-
-
1 row in
set
(
0.00
sec)
-
1.6 日志分析工具mysqldumpslow
在生產環境中，如果要手工分析日志，查找、分析SQL，顯然是個體力活，MySQL提供了日志分析工具mysqldumpslow
MySQL 慢查詢日志分析
mysql> show variables like '%slow%';
+---------------------+-------------------------+
| Variable_name | Value |
+---------------------+-------------------------+
| log_slow_queries | ON |
| slow_launch_time | 2 |
| slow_query_log | ON |
| slow_query_log_file | D:/log/slow.txt |
+---------------------+-------------------------+
其中,各參數說明如下:
slow_launch_time: 慢查詢超過的執行時間值
slow_query_log: 是否打開慢查詢日志功能
show_query_log_file:慢查詢日志目錄
開啟慢查詢日志功能:
mysql配置文件(win mysql.ini linux mysql.conf)下,
[mysqld]
log-slow-queries ="D:/xampp/mysql/long.txt"
long_query_time = 1
log-slow-queries=/var/lib/mysql/slowquery.log (指定日志文件存放位置，可以為空，系統會給一個缺省的文件host_name-slow.log)
long_query_time=2 (記錄超過的時間，默認為10s)
log-queries-not-using-indexes (log下來沒有使用索引的query,可以根據情況決定是否開啟)
log-long-format (如果設置了，所有沒有使用索引的查詢也將被記錄)
long_query_time=2 (記錄超過的時間，默認為10s)
log-queries-not-using-indexes (log下來沒有使用索引的query,可以根據情況決定是否開啟)
log-long-format (如果設置了，所有沒有使用索引的查詢也將被記錄)
mysqldumpslow, mysql官方提供的慢查詢日志分析工具. 輸出圖表如下:
主要功能是, 統計不同慢sql的
出現次數(Count),
執行最長時間(Time),
累計總耗費時間(Time),
等待鎖的時間(Lock),
發送給客戶端的行總數(Rows),
掃描的行總數(Rows),
用戶以及sql語句本身(抽象了一下格式, 比如 limit 1, 20 用 limit N,N 表示).
mysqlsla, hackmysql.com推出的一款日志分析工具(該網站還維護了 mysqlreport, mysqlidxchk 等比較實用的mysql工具)
整體來說, 功能非常強大. 數據報表,非常有利於分析慢查詢的原因, 包括執行頻率, 數據量, 查詢消耗等.
格式說明如下:
總查詢次數 (queries total), 去重后的sql數量 (unique)
輸出報表的內容排序(sorted by)
最重大的慢sql統計信息, 包括 平均執行時間, 等待鎖時間, 結果行的總數, 掃描的行總數.
Count, sql的執行次數及占總的slow log數量的百分比.
Time, 執行時間, 包括總時間, 平均時間, 最小, 最大時間, 時間占到總慢sql時間的百分比.
95% of Time, 去除最快和最慢的sql, 覆蓋率占95%的sql的執行時間.
Lock Time, 等待鎖的時間.
95% of Lock , 95%的慢sql等待鎖時間.
Rows sent, 結果行統計數量, 包括平均, 最小, 最大數量.
Rows examined, 掃描的行數量.
Rows examined, 掃描的行數量.
Database, 屬於哪個數據庫
Users, 哪個用戶,IP, 占到所有用戶執行的sql百分比
Query abstract, 抽象后的sql語句
Query sample, sql語句
除了以上的輸出, 官方還提供了很多定制化參數, 是一款不可多得的好工具.
功能上有點瑕疵, 不僅把所有的 slow log 打印到屏幕上, 而且統計也只有數量而已. 不推薦使用.
mysql-log-filter, google code上找到的一個分析工具.提供了 python 和 php 兩種可執行的腳本.
http://code.google.com/p/mysql-log-filter/
http://code.google.com/p/mysql-log-filter/
功能上比官方的mysqldumpslow, 多了查詢時間的統計信息(平均,最大, 累計), 其他功能都與 mysqldumpslow類似.
特色功能除了統計信息外, 還針對輸出內容做了排版和格式化, 保證整體輸出的簡潔. 喜歡簡潔報表的朋友, 推薦使用一下.
特色功能除了統計信息外, 還針對輸出內容做了排版和格式化, 保證整體輸出的簡潔. 喜歡簡潔報表的朋友, 推薦使用一下.
功能上, 列出了總的慢查詢次數和類型, 去重后的sql語句, 執行次數及其占總的slow log數量的百分比.
從整體輸出樣式來看, 比mysql-log-filter還要簡潔. 省去了很多不必要的內容. 對於只想看sql語句及執行次數的用戶來說, 比較推薦.
從整體輸出樣式來看, 比mysql-log-filter還要簡潔. 省去了很多不必要的內容. 對於只想看sql語句及執行次數的用戶來說, 比較推薦.
總結
| 工具/功能 | 一般統計信息 | 高級統計信息 | 腳本 | 優勢 |
| mysqldumpslow | 支持 | 不支持 | perl | mysql官方自帶 |
| mysqlsla | 支持 | 支持 | perl | 功能強大,數據報表齊全,定制化能力強. |
| mysql-explain-slow-log | 支持 | 不支持 | perl | 無 |
| mysql-log-filter | 支持 | 部分支持 | python or php | 不失功能的前提下,保持輸出簡潔 |
| myprofi | 支持 | 不支持 | php | 非常精簡 |
1、MySQL 慢查詢日志分析及可視化結果 – 運維生存時間 http://www.ttlsa.com/mysql/mysql-slow-query-log-analysis-and-visualization-of-results/
2、Mysql 慢日志分析系統搭建 —— Box Anemometer_SleePerSir_新浪博客 http://blog.sina.com.cn/s/blog_c2839d2a0102wkuv.html
3、mysql性能監控軟件 慢日志分析利器 - pmm server https://blog.csdn.net/john1337/article/details/70855293
4、MySQL 慢查詢日志(Slow Query Log) - CSDN博客 https://blog.csdn.net/leshami/article/details/39829605
5、關於MySQL 通用查詢日志和慢查詢日志分析 - CSDN博客 https://blog.csdn.net/timchen525/article/details/75268151
6、mysql 慢日志分析工具pt-query-digest - CSDN博客 https://blog.csdn.net/stevendbaguo/article/details/47612359
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原文地址：https://blog.csdn.net/enweitech/article/details/80239189