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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>:错误日志、二进制日志、通用查询日志、慢查询日志等等。这里主要介绍下比较常用的两个功能:通用查询日志和慢查询日志。</p><p style="background-color:rgb(255,255,255);"><span style="font-weight:700;">1)通用查询日志</span>:记录建立的客户端连接和执行的语句。</p><p style="background-color:rgb(255,255,255);"><span style="font-weight:700;">2)慢查询日志</span>:记录所有执行时间超过long_query_time秒的所有查询或者不使用索引的查询</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日志文件系统的组成</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);">&nbsp;&nbsp;&nbsp;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);">错误日志</a><span style="font-family:'Courier New';background-color:rgb(255,255,255);">:记录启动、运行或停止mysqld时出现的问题。</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);">&nbsp;&nbsp;<strong>&nbsp;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);">:记录建立的客户端连接和执行的语句。</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);">&nbsp;&nbsp;&nbsp;c、更新日志:记录更改数据的语句。该日志在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);">&nbsp;&nbsp;&nbsp;<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);">二进制日志</a><span style="font-family:'Courier New';background-color:rgb(255,255,255);">:记录所有更改数据的语句。还用于复制。</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);">&nbsp;&nbsp;&nbsp;<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);">慢查询日志</a><span style="font-family:'Courier New';background-color:rgb(255,255,255);">:记录所有执行时间超过long_query_time秒的所有查询或不使用索引的查询。</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);">&nbsp;&nbsp;&nbsp;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);">&nbsp;缺省情况下,所有日志创建于mysqld数据目录中。</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);">&nbsp;&nbsp;&nbsp;可以通过刷新日志,来强制mysqld来关闭和重新打开日志文件(或者在某些情况下切换到一个新的日志)。</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);">&nbsp;&nbsp;&nbsp;当你执行一个FLUSH LOGS语句或执行mysqladmin flush-logs或mysqladmin refresh时,则日志被老化。</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);">&nbsp;&nbsp;&nbsp;对于存在MySQL复制的情形下,从复制服务器将维护更多日志文件,被称为接替日志。</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);">同大多数关系型数据库一样,日志文件是MySQL数据库的重要组成部分。MySQL有几种不同的日志文件,通常包括错误日志文件,二进制日志,通用日志,慢查询日志,等等。这些日志可以帮助我们定位mysqld内部发生的事件,数据库性能故障,记录数据的变更历史,用户恢复数据库等等。</span>今天我们要讲的是如何分析和查询mysql慢日志(主要影响程序调用和前端数据呈现)。</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 是用来记录执行时间较长(超过long_query_time秒)的sql的一种日志工具</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;">启用 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;">有两种启用方式:</div><span style="color:#222222;font-family:tahoma, arial, 'Microsoft YaHei';font-size:14px;">1, 在my.cnf 里 通过 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进程启动时,指定--log-slow-queries[=file_name]选项</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;">比较的五款常用工具<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;">开源的MySQL慢日志查询监控工具</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);">&nbsp;</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);">慢查询日志<br></span><span style="font-family:'Courier New';background-color:rgb(255,255,255);">&nbsp;&nbsp;&nbsp;慢查询日志是将mysql服务器中影响数据库性能的相关SQL语句记录到日志文件,通过对这些特殊的SQL语句分析,改进以达到提高数据库性能的目的。</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);">&nbsp;&nbsp;&nbsp;通过使用--slow_query_log[={0|1}]选项来启用慢查询日志。所有执行时间超过long_query_time秒的SQL语句都会被记录到慢查询日志。</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);">&nbsp;&nbsp;&nbsp;缺省情况下hostname-slow.log为慢查询日志文件安名,存放到数据目录,同时缺省情况下未开启慢查询日志。</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);">&nbsp;&nbsp;&nbsp;缺省情况下数据库相关管理型SQL(比如OPTIMIZE TABLE、ANALYZE TABLE和ALTER TABLE)不会被记录到日志。</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);">&nbsp;&nbsp;&nbsp;对于管理型SQL可以通过--log-slow-admin-statements开启记录管理型慢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);">&nbsp;&nbsp;&nbsp;mysqld在语句执行完并且所有锁释放后记入慢查询日志。记录顺序可以与执行顺序不相同。获得初使表锁定的时间不算作执行时间。</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);">&nbsp;&nbsp;&nbsp;</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);">&nbsp;&nbsp;&nbsp;可以使用mysqldumpslow命令获得日志中显示的查询摘要来处理慢查询日志。</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);">&nbsp;&nbsp;&nbsp;用查询缓存处理的查询不加到慢查询日志中,表有零行或一行而不能从索引中受益的查询也不写入慢查询日志。</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);">&nbsp;&nbsp;&nbsp;MySQL服务器按以下顺序记录SQL是否写入到慢查询日志</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);">&nbsp; 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);">&nbsp;b. The query must have taken at least long_query_time seconds, or log_queries_not_using_indexes must be enabled and&nbsp;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);">&nbsp; &nbsp; 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);">&nbsp;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自带的用来分析慢查询的工具,当然不止这一种工具,还有percona-toolkit是percona公司出的一组命令行工具的集合,用来执行各种通过手工执行非常复杂和麻烦的mysql相关任务,包含以下内容:</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);">检查master和slave数据一致性/记录有效的归档/服务器信息汇总/分析和统计日志,为了省事这块使用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);">需要开启mysql的慢查询日志,否则无法进行统计分析,开启mysql慢查询日志需要在mysql的配置文件中进行如下配置:</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;">#定义超过1秒的查询计数到变量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 简介</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);">开启慢查询日志,可以让MySQL记录下查询超过指定时间的语句,通过定位分析性能的瓶颈,才能更好的优化数据库系统的性能。</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 登录数据库查看</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);">因为没有设置设置密码,有密码的在 mysql –uroot –p 接密码</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 进入MySql 查询是否开了慢查询</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&gt; <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="登录后复制" 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);">参数说明:</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 慢查询开启状态&nbsp; OFF 未开启 ON 为开启</li><li style="margin:0px;padding:0px;list-style:disc;">slow_query_log_file 慢查询日志存放的位置(这个目录需要MySQL的运行帐号的可写权限,一般设置为MySQL的数据存放目录)</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 查看慢查询超时时间</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&gt; <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="登录后复制" 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 查询超过多少秒才记录&nbsp;&nbsp; 默认10秒 修改为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:(不推荐)</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:优点临时开启慢查询,不需要重启数据库&nbsp; 缺点:MySql 重启慢查询失效</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);">推荐:根据业务需求,建议使用第二种,临时可以用第一种</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);">默认情况下slow_query_log的值为OFF,表示慢查询日志是禁用的,可以通过设置slow_query_log的值来开启,如下所示::是否开启慢查询日志,1表示开启,0表示关闭。</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 查看是否开启慢查询</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&gt; <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="登录后复制" 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);">输入 语句修改(重启后失效,建议在/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&gt; <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="登录后复制" 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&gt; <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="登录后复制" 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:(推荐)</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 慢查询,好多人不知道my.cnf 路径,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);">备注:我的MySQL 是编译的 路径为 /etc/my.cnf (一般都是这里)</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 ###(一般都是这里)

1.4.1.1 修改

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[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

参数说明:

  1. slow_query_log 慢查询开启状态  1 为开启
  2. slow_query_log_file 慢查询日志存放的位置
  3. long_query_time 查询超过多少秒才记录   默认10秒 修改为1秒

修改完重启MySQL

1.5 查看、测试

1.5.1.1 插入一条测试慢查询


   
  1. mysql> select sleep( 2);
  2. + ----------+
  3. | sleep(2) |
  4. + ----------+
  5. | 0 |
  6. + ----------+
  7. 1 row in set ( 2.00 sec)

1.5.1.2 查看慢查询日志

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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 通过MySQL命令查看有多少慢查询


   
  1. mysql> show global status like '%Slow_queries%';
  2. + ---------------+-------+
  3. | Variable_name | Value |
  4. + ---------------+-------+
  5. | Slow_queries | 1 |
  6. + ---------------+-------+
  7. 1 row in set ( 0.00 sec)

1.6 日志分析工具mysqldumpslow

在生产环境中,如果要手工分析日志,查找、分析SQL,显然是个体力活,MySQL提供了日志分析工具mysqldumpslow

MySQL 慢查询日志分析

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,各参数说明如下:

slow_launch_time: 慢查询超过的执行时间值

 slow_query_log: 是否打开慢查询日志功能

show_query_log_file:慢查询日志目录  

开启慢查询日志功能:

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,可以为空,系统会给一个缺省的文件host_name-slow.log)
long_query_time=2 (记录超过的时间,默认为10s)
log-queries-not-using-indexes (log下来没有使用索引的query,可以根据情况决定是否开启)
log-long-format (如果设置了,所有没有使用索引的查询也将被记录)

mysqldumpslow, mysql官方提供的慢查询日志分析工具. 输出图表如下:
主要功能是, 统计不同慢sql的
出现次数(Count), 
执行最长时间(Time), 
累计总耗费时间(Time), 
等待锁的时间(Lock), 
发送给客户端的行总数(Rows), 
扫描的行总数(Rows), 
用户以及sql语句本身(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(该网站还维护了 mysqlreport, mysqlidxchk 等比较实用的mysql工具)
整体来说, 功能非常强大. 数据报表,非常有利于分析慢查询的原因, 包括执行频率, 数据量, 查询消耗等.

格式说明如下:
总查询次数 (queries total), 去重后的sql数量 (unique)
输出报表的内容排序(sorted by)
最重大的慢sql统计信息, 包括 平均执行时间, 等待锁时间, 结果行的总数, 扫描的行总数.

Count, sql的执行次数及占总的slow log数量的百分比.
Time, 执行时间, 包括总时间, 平均时间, 最小, 最大时间, 时间占到总慢sql时间的百分比.
95% of Time, 去除最快和最慢的sql, 覆盖率占95%的sql的执行时间.
Lock Time, 等待锁的时间.
95% of Lock , 95%的慢sql等待锁时间.
Rows sent, 结果行统计数量, 包括平均, 最小, 最大数量.
Rows examined, 扫描的行数量.
Database, 属于哪个数据库
Users, 哪个用户,IP, 占到所有用户执行的sql百分比

Query abstract, 抽象后的sql语句
Query sample, sql语句

除了以上的输出, 官方还提供了很多定制化参数, 是一款不可多得的好工具.

mysql-explain-slow-log, 德国人写的一个perl脚本.
IT虾米网


功能上有点瑕疵, 不仅把所有的 slow log 打印到屏幕上, 而且统计也只有数量而已. 不推荐使用.
mysql-log-filter, google code上找到的一个分析工具.提供了 python 和 php 两种可执行的脚本.
IT虾米网
功能上比官方的mysqldumpslow, 多了查询时间的统计信息(平均,最大, 累计), 其他功能都与 mysqldumpslow类似.
特色功能除了统计信息外, 还针对输出内容做了排版和格式化, 保证整体输出的简洁. 喜欢简洁报表的朋友, 推荐使用一下.
myprofi, 纯php写的一个开源分析工具.项目在 sourceforge 上.
IT虾米网

 
功能上, 列出了总的慢查询次数和类型, 去重后的sql语句, 执行次数及其占总的slow log数量的百分比.
从整体输出样式来看, 比mysql-log-filter还要简洁. 省去了很多不必要的内容. 对于只想看sql语句及执行次数的用户来说, 比较推荐.

总结

工具/功能 一般统计信息 高级统计信息 脚本 优势
mysqldumpslow 支持 不支持 perl mysql官方自带
mysqlsla 支持 支持 perl 功能强大,数据报表齐全,定制化能力强.
mysql-explain-slow-log 支持 不支持 perl
mysql-log-filter 支持 部分支持 python or php 不失功能的前提下,保持输出简洁
myprofi 支持 不支持 php 非常精简
【参考资料】
1、MySQL 慢查询日志分析及可视化结果 – 运维生存时间 IT虾米网
2、Mysql 慢日志分析系统搭建 —— Box Anemometer_SleePerSir_新浪博客 IT虾米网
3、mysql性能监控软件 慢日志分析利器 - pmm server IT虾米网

4、MySQL 慢查询日志(Slow Query Log) - CSDN博客 IT虾米网

5、关于MySQL 通用查询日志和慢查询日志分析 - CSDN博客 IT虾米网

6、mysql 慢日志分析工具pt-query-digest - CSDN博客 IT虾米网

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