天津网站建设哪家权威,做网站ui主要研究内容,怎么做企业网站仿站,2008 iis搭建网站1.服务器级别的锁等待可以通过show processlist看到等待锁的线程id#xff0c;但是无法知道究竟哪个线程持有锁可以通过mysqladmin debug相关等待锁的线程以及谁持有锁可以在错误日志中找到2.存储引擎层的锁等待则比较麻烦#xff0c;以下是innodb存储引擎中锁等待以及哪个线…1.服务器级别的锁等待 可以通过show processlist看到等待锁的线程id但是无法知道究竟哪个线程持有锁 可以通过mysqladmin debug 相关等待锁的线程以及谁持有锁可以在错误日志中找到 2.存储引擎层的锁等待则比较麻烦以下是innodb存储引擎中锁等待以及哪个线程持有锁的查找sql SELECT r.trx_id AS waiting_trx_id, r.trx_mysql_thread_id AS waiting_thread, TIMESTAMPDIFF(SECOND, r.trx_wait_started, CURRENT_TIMESTAMP) AS wait_time, r.trx_query AS waiting_query, l.lock_table AS waiting_table_lock, b.trx_id AS blocking_trx_id, b.trx_mysql_thread_id AS blocking_thread, SUBSTRING(p.host,1,INSTR(p.host, :) -1 ) AS blocking_host, SUBSTRING(p.host, INSTR(p.host, :) 1 ) AS block_port, IF(p.commandSleep,p.time,0) AS idle_in_trx, b.trx_query AS blcoking_query from information_schema.innodb_lock_waits AS w INNER JOIN information_schema.innodb_trx AS b ON b.trx_idw.blocking_trx_id INNER JOIN information_schema.innodb_trx AS r ON r.trx_id w.requesting_trx_id INNER JOIN information_schema.innodb_locks AS l ON w.requested_lock_id l.lock_id LEFT JOIN information_schema.processlist AS p ON p.id b.trx_mysql_thread_id ORDER BY wait_time DESC\G 3.如果因为线程在一个事务中空闲而正在遭受大量的锁操作下面查询显示存储引擎层有多少查询被哪些线程阻塞。 SELECT CONCAT(thread , b.trx_mysql_thread_id, from ,p.host) AS who_blocks, IF (p.command Sleep,p.time, 0) AS idle_in_trx, MAX(TIMESTAMPDIFF(SECOND,r.trx_wait_started,NOW())) AS max_wait_time, COUNT(*) AS num_waiters FROM information_schema.innodb_lock_waits as w inner join information_schema.innodb_trx as b on b.trx_id w.blocking_trx_id inner join information_schema.innodb_trx as r on r.trx_id w.requesting_trx_id left join information_schema.processlist as p on p.id b.trx_mysql_thread_id group by who_blocks order by num_waiters desc\G 参考资料 高性能mysql第三版 转载于:https://www.cnblogs.com/gomysql/p/3608466.html
