Mysql状态信息查询

一.连接相关
二.show status
三.其它

一.连接相关

查看连接线程相关的系统变量的设置值

show variables like 'thread%';

查看系统被连接的次数

show status like 'connections';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| Connections | 620 |

+---------------+-------+

当前系统中连接线程的状态值

show status like '%thread%';

+------------------------+-------+

| Variable_name | Value |

+------------------------+-------+

| Delayed_insert_threads | 0 |

| Slow_launch_threads | 0 |

| Threads_cached | 3 |

| Threads_connected | 4 |

| Threads_created | 7 |

| Threads_running | 1 |

+------------------------+-------+

系统启动到现在共接受到客户端的连接620次，共创建了7个连接线程，当前有1个连接线程处于和客户端连接的状态，而3个连接状态的线程中只有一个处于 active 状态，即只有一个正在处理客户端提交的请求，。而在Thread Cache池中共缓存了3个连接线程。

Thread Cache 命中率：

Thread_Cache_Hit = (Connections - Threads_created) / Connections * 100%;

二.show status

三.其它

检测mysql server是否正常提供服务

mysqladmin -u sky -ppwd -h localhost ping

获取mysql当前的几个状态值

mysqladmin -u sky -ppwd -h localhost status

获取数据库当前的连接信息

mysqladmin -u sky -ppwd -h localhost processlist

获取当前数据库的连接数

mysql -u root -p123456 -BNe "select host,count(host) from processlist group by host;" information_schema

显示mysql的uptime

mysql -e"SHOW STATUS LIKE '%uptime%'"|awk '/ptime/{ calc = $NF / 3600;print $(NF-1), calc"Hour" }'

查看数据库的大小

select table_schema,round(sum(data_length+index_length)/1024/1024,4) from information_schema.tables group by table_schema;

查看某个表的列信息

mysql -u <user> --password=<password> -e "SHOW COLUMNS FROM <table>" <database> | awk '{print $1}' | tr "\n" "," | sed 's/,$//g'

mysql dump数据导出

mysqldump -uroot -T/tmp/mysqldump test test_outfile --fields-enclosed-by=\" --fields-terminated-by=,

mysql数据导入

mysqlimport --user=name --password=pwd test --fields-enclosed-by=\" --fields-terminated-by=, /tmp/test_outfile.txt LOAD DATA INFILE '/tmp/test_outfile.txt' INTO TABLE test_outfile FIELDS TERMINATED BY '"' ENCLOSED BY ',';

查看当前数据库的状态

mysql>show status

mysqlcheck 工具程序可以检查(check),修复( repair),分析( analyze)和优化(optimize)MySQL Server 中的表

mysqlcheck -u root -p123456 --all-databases

mysql qps查询 QPS = Questions(or Queries) / Seconds

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Questions"

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Queries"

mysql Key Buffer 命中率 key_buffer_read_hits = (1 - Key_reads / Key_read_requests) * 100% key_buffer_write_hits= (1 - Key_writes / Key_write_requests) * 100%

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Key%"

mysql Innodb Buffer 命中率 innodb_buffer_read_hits=(1-Innodb_buffer_pool_reads/Innodb_buffer_pool_read_requests) * 100%

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Innodb_buffer_pool_read%"

mysql Query Cache 命中率 Query_cache_hits= (Qcache_hits / (Qcache_hits + Qcache_inserts)) * 100%

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Qcache%"

mysql Table Cache 状态量

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Open%"

mysql Thread Cache 命中率 Thread_cache_hits = (1 - Threads_created / Connections) * 100% 正常来说,Thread Cache 命中率要在 90% 以上才算比较合理。

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Thread%"

mysql 锁定状态:锁定状态包括表锁和行锁两种,我们可以通过系统状态变量获得锁定总次数,锁定造成其他线程等待的次数,以及锁定等待时间信息

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "%lock%"

mysql 复制延时量在slave节点执行

mysql>SHOW SLAVE STATUS

mysql Tmp table 状况 Tmp Table 的状况主要是用于监控 MySQL 使用临时表的量是否过多,是否有临时表过大而不得不从内存中换出到磁盘文件上

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Created_tmp%"

mysql Binlog Cache 使用状况:Binlog Cache 用于存放还未写入磁盘的 Binlog 信息。

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Binlog_cache%"

mysql nnodb_log_waits 量:Innodb_log_waits 状态变量直接反应出 Innodb Log Buffer 空间不足造成等待的次数

mysql>SHOW /*!50000 GLOBAL */ STATUS LIKE "Innodb_log_waits