mysql服务器cpu爆满解决办法
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1、通过show processlist找到耗时最长的
mysql> show processlist;
+----+------+-----------------+------+---------+------+--------------+------------------------------------------------------------------------------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+-----------------+------+---------+------+--------------+------------------------------------------------------------------------------------------------------+
| 19 | root | localhost:60604 | big | Query | 1533 | Sending data | SELECT count(*) num,city FROM `ih_user_temp` where city in (select city from ih_user_temp where city |
| 25 | root | localhost | NULL | Query | 0 | NULL | show processlist |
+----+------+-----------------+------+---------+------+--------------+------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
2、先杀掉该进程
mysql> kill 19;
Query OK, 0 rows affected (0.01 sec)
[mysqld]
slow_query_log=1 #开启慢查询
long_query_time=5 #慢查询时间
log-slow-queries = /var/log/mysql/slowquery.log #需有写入权限
4、使用explain 优化sql语句，
引起cpu过高的sql一般集中在order by、group by、批量insert、嵌套子查询等sql语句中
5、调整my.cnf的query_cache_size和tmp_table_size的值
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