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mysql show processlist中state含义

Jun 07, 2016 pm 04:41 PM
mysql state

SHOW PROCESSLIST显示哪些线程正在运行。您也可以使用mysqladmin processlist语句得到此信息。如果您有SUPER权限,您可以看到所有线程。否则,您只能看到您自己的线程 Checking table: 正在检查数据表 Closing tables: 正在将表中修改的数据刷新到磁盘中,同

SHOW PROCESSLIST显示哪些线程正在运行。您也可以使用mysqladmin processlist语句得到此信息。如果您有SUPER权限,您可以看到所有线程。否则,您只能看到您自己的线程

Checking table:
正在检查数据表

Closing tables:
正在将表中修改的数据刷新到磁盘中,同时正在关闭已经用完的表,正常情况,这是一个很快的操作,一般情况很难看到,如果这个值不幸出现甚至多,那么就应该确认磁盘空间是否被填满或者磁盘是否正高负荷运作

Connect Out:
复制从服务器正在连接主服务器。

Copying to tmp table on disk:
由于临时结果集大于tmp_table_size,正在将临时表从内存存储转为磁盘存储以此节省内存

Creating tmp table:
正在创建临时表以存放部分查询结果

deleting from main table:
服务器正在执行多表删除中的第一部分,刚删除第一个表

deleting from reference tables:
服务器正在执行多表删除中的第二部分,正在删除其他表的记录

Flushing tables:
正在执行FLUSH TABLES,等待其他线程关闭数据表

Killed
发送了一个kill请求给某线程,那么这个线程将会检查kill标志位,同时会放弃下一个kill请求,MySQL会在每次的主循环中检查kill标志位,不过有些情况下该线程可能会过一小段才能死掉。如果该线程程被其他线程锁住了,那么kill请求会在锁释放时马上生效

Locked
被其他查询锁住了

Sending data
正在处理SELECT查询的记录,同时正在把结果发送给客户端

Sorting for group
正在为GROUP BY做排序

Sorting for order
正在为ORDER BY做排序

Opening tables
这个过程应该会很快,除非受到其他因素的干扰。例如,在执ALTER TABLE或LOCK TABLE语句行完以前,数据表无法被其他线程打开。正尝试打开一个表

Removing duplicates
正在执行一个SELECT DISTINCT方式的查询,但是MySQL无法在前一个阶段优化掉那些重复的记录。因此,MySQL需要再次去掉重复的记录,然后再把结果发送给客户端

Reopen table
获得了对一个表的锁,但是必须在表结构修改之后才能获得这个锁。已经释放锁,关闭数据表,正尝试重新打开数据表

Repair by sorting
修复指令正在排序以创建索引

Repair with keycache
修复指令正在利用索引缓存一个一个地创建新索引。它会比Repair by sorting慢些

Searching rows for update
正在讲符合条件的记录找出来以备更新。它必须在UPDATE要修改相关的记录之前就完成了

Sleeping
正在等待客户端发送新请求

System lock
正在等待取得一个外部的系统锁。如果当前没有运行多个mysqld服务器同时请求同一个表,那么可以通过
增加–skip-external-locking参数来禁止外部系统锁

Upgrading lock
INSERT DELAYED正在尝试取得一个锁表以插入新记录

Updating
正在搜索匹配的记录,并且修改它们

User Lock
正在等待GET_LOCK()

Waiting for tables
该线程得到通知,数据表结构已经被修改了,需要重新打开数据表以取得新的结构。然后,为了能的重新打开数据表,必须等
到所有其他线程关闭这个表。以下几种情况下会产生这个通知:
FLUSH TABLES tbl_name, ALTER TABLE, RENAME TABLE, REPAIR TABLE, ANALYZE TABLE,或OPTIMIZE TABLE

waiting for handler insert
INSERT DELAYED已经处理完了所有待处理的插入操作,正在等待新的请求

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