MYSQL5.7.9開啟慢查詢日志的技巧

2024-07-24 12:45:03

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用MYSQL 5.7.9 作為ZABBIX 2.4.7 的監控數據庫. 前段時間開啟了慢查詢日志, 后來發現慢查詢日志膨脹到了700M

查看最后100條大部分都是 0.1 秒的后來想改, 以前是動態設置的 set global slow_query_log=1; 方式的 .

然后想直接用配置文件/etc/my.cnf 配慢查詢

# Remove leading # and set to the amount of RAM for the most important data# cache in MySQL. Start at % of total RAM for dedicated server, else %.innodb_buffer_pool_size = M# Remove leading # to turn on a very important data integrity option: logging# changes to the binary log between backups.# log_bin# These are commonly set, remove the # and set as required.basedir = /LANMP/mysqldatadir = /MYSQLDATA/dataport = # server_id = .....socket = /tmp/mysql.sock# Remove leading # to set options mainly useful for reporting servers.# The server defaults are faster for transactions and fast SELECTs.# Adjust sizes as needed, experiment to find the optimal values.join_buffer_size = Msort_buffer_size = Mread_rnd_buffer_size = Msql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLEScharacter_set_server=utfinit_connect='SET NAMES utf'slow_query_log = slow_query_log_file = /MYSQLDATA/mysql_slow_query.loglong_query_time = log_queries_not_using_indexes = ON

反復啟動了好多次 service mysqld restart

mysql> show variables like '%query%';+------------------------------+---------------------------------+| Variable_name | Value |+------------------------------+---------------------------------+| binlog_rows_query_log_events | OFF || ft_query_expansion_limit | 20 || have_query_cache | YES || long_query_time | 5.000000 || query_alloc_block_size | 8192 || query_cache_limit | 1048576 || query_cache_min_res_unit | 4096 || query_cache_size | 1048576 || query_cache_type | OFF || query_cache_wlock_invalidate | OFF || query_prealloc_size | 8192 || slow_query_log | ON || slow_query_log_file | /MYSQLDATA/mysql_slow_query.log |+------------------------------+---------------------------------+13 rows in set (0.00 sec)

老是OFF 狀態而其他的 LONG_QUERY_TIME 得到了改變 5秒

用動態方式設置報錯

mysql> set global slow_query_log=1;ERROR 29 (HY000): File '/MYSQLDATA/mysql_slow_query.log' not found (Errcode: 13 - Permission denied)

對我已經把它給刪了, 為傻不自己創建個?

只好自己touch 一個

還是報錯 ?

ps -ef |grep mysqld 發現還有個mysql用戶啟動了mysql

看來是用mysql用戶讀取慢查詢日志的用戶權限問題啦

下面給大家介紹開啟mysql慢查詢日志

查看配置：

//查詢慢查詢時間show variables like "long_query_time";默認10s //查看慢查詢配置情況show status like "%slow_queries%"; //查看慢查詢日志路徑show variables like "%slow%";

修改配置文件