mysql问题排查

-- 显示正在运行的进程
show processlist;

-- 执行时间长
SELECT * from information_schema.`PROCESSLIST` WHERE Time > 1000 AND db = 'cdc' ORDER BY TIME desc;

-- 查询表锁
show OPEN TABLES where In_use > 0;

-- 1：查看当前的事务
SELECT * FROM INFORMATION_SCHEMA.INNODB_TRX;

-- 2：查看当前锁定的事务
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;

-- 3：查看当前等锁的事务
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;

-- 查询最大连接数
SHOW VARIABLES LIKE 'max_connections';