Mysql之日常运维命令总结-编程知识

Mysql之日常运维命令总结

news/2024/9/20 14:08:25/文章来源:https://www.cnblogs.com/OpenSourceSite/p/18291399

1、连接MySQL数据库

mysql -uroot -p'password'
mysql -uroot -p'password' -h 127.0.0.1 -P 3306
mysql -uroot -p'password' -S /path/to/mysql.sock

2、查看当前数据库中的会话状态

show processlist;

3、查看当前数据库中的活动会话（排除掉空闲Sleep状态的会话）

select * from information_schema.processlist where command <> 'Sleep';--8.0以后版本建议使用performance_schema:
select * from performance_schema.processlist where command <> 'Sleep';--排除掉自己的会话连接
select * from information_schema.processlist where command <> 'Sleep' and id <> connection_id();select * from performance_schema.processlist where command <> 'Sleep' and id <> connection_id();--也可以通过其他条件来排查掉自己不想要的会话信息：如user in  或者 db in ,host等查询条件来过滤。

4、查看数据库的总大小

--数据库总大小
select round(sum(data_length+index_length)/1024/1024/1024,2) as 'DBSIZE_GB' from information_schema.tables;

5、查看数据库中各个库的大小合计

--数据库大小信息：
select table_schema,round(sum(data_length+index_length)/1024/1024/1024,3) as 'SIZE_GB' from information_schema.tables where table_schema not in ('sys','mysql','information_schema','performance_schema') group by table_schema ;

6、查看数据库中的TOP 30大表信息

--Top 30大表信息：
select table_schema,table_name,round((data_length+index_length)/1024/1024,2) as 'SIZE_MB',table_rows,engine from information_schema.tables where table_schema not in ('sys','mysql','information_schema','performance_schema') order by 3 desc limit 30 ;

7、查看表和索引的统计信息：

--表统计信息：
select * from mysql.innodb_table_stats where database_name='db_name' and table_name='table_name';--索引统计信息：
select * from mysql.innodb_index_stats where database_name='' and table_name='' and index_name='idx_name';

8、查询锁等待时持续间大于20秒的SQL信息

  SELECT trx_mysql_thread_id AS PROCESSLIST_ID,NOW(),TRX_STARTED,TO_SECONDS(now())-TO_SECONDS(trx_started) AS TRX_LAST_TIME ,USER,HOST,DB,TRX_QUERY
FROM INFORMATION_SCHEMA.INNODB_TRX trx
JOIN sys.innodb_lock_waits lw ON trx.trx_mysql_thread_id=lw.waiting_pid
JOIN INFORMATION_SCHEMA.processlist pcl ON trx.trx_mysql_thread_id=pcl.id
WHERE trx_mysql_thread_id != connection_id()AND TO_SECONDS(now())-TO_SECONDS(trx_started) >= 20 ;

9、查询MySQL锁等待表的详细信息

-- sys库锁等待表：
select * from sys.innodb_lock_waits\G

10、查询长事务SQL

--长事务（包含未关闭的事务）
SELECT thr.processlist_id AS mysql_thread_id,concat(PROCESSLIST_USER,'@',PROCESSLIST_HOST) User,Command,FORMAT_PICO_TIME(trx.timer_wait) AS trx_duration,current_statement as `latest_statement`FROM performance_schema.events_transactions_current trxINNER JOIN performance_schema.threads thr USING (thread_id)LEFT JOIN sys.processlist p ON p.thd_id=thread_idWHERE thr.processlist_id IS NOT NULL AND PROCESSLIST_USER IS NOT NULL AND trx.state = 'ACTIVE'GROUP BY thread_id, timer_wait ORDER BY TIMER_WAIT DESC LIMIT 10;

11、查看当前DDL执行的进度

use performance_schema;
select * from setup_instruments where name like 'stage/innodb/alter%';
select * from setup_consumers where name like '%stages%';--如果上面查询结果为NO，则需要做如下配置：
update set_instrucments set enabled = 'YES' where name like 'stage/innodb/alter%';
update set_consumers set enabled = 'YES' where name like '%stages%';-- 查询DDL执行的进度：
select stmt.sql_text,stage.event_name,concat(work_completed, '/', work_estimated) as progress,concat(round(100 * work_completed / work_estimated, 2), ' %') as processing_pct,sys.format_time(stage.timer_wait) as time_costs,concat(round((stage.timer_end - stmt.timer_start) / 1e12 *(work_estimated - work_completed) / work_completed,2),' s') as remaining_secondsfrom performance_schema.events_stages_current     stage,performance_schema.events_statements_current stmtwhere stage.thread_id = stmt.thread_idand stage.nesting_event_id = stmt.event_id\G

12、执行次数最多的TOP 10 SQL

--执行次数前10 SQL
SELECT QUERY_SAMPLE_TEXT,COUNT_STAR,FIRST_SEEN,LAST_SEEN FROM events_statements_summary_by_digest ORDER BY COUNT_STAR DESC LIMIT 10;

13、平均响应时间最长的TOP 10 SQL

--平均响应时间TOP 10 SQL
SELECT QUERY_SAMPLE_TEXT,AVG_TIMER_WAIT FROM events_statements_summary_by_digest ORDER BY AVG_TIMER_WAIT DESC limit 10;

14、排序次数最多的TOP 10 SQL

--排序此时最多TOP 10 SQL
SELECT QUERY_SAMPLE_TEXT,SUM_SORT_ROWS FROM events_statements_summary_by_digest ORDER BY SUM_SORT_ROWS DESC LIMIT 10;

15、扫描记录数最多的 TOP 10 SQL

--扫描行最多的 TOP 10 SQL 
SELECT QUERY_SAMPLE_TEXT,SUM_ROWS_EXAMINED FROM events_statements_summary_by_digest ORDER BY SUM_ROWS_EXAMINED DESC LIMIT 10;

16、使用临时表最多的TOP 10 SQL

--使用临时表最多的TOP 10 SQL
SELECT QUERY_SAMPLE_TEXT,SUM_CREATED_TMP_TABLES,SUM_CREATED_TMP_DISK_TABLES FROM events_statements_summary_by_digest ORDER BY SUM_CREATED_TMP_TABLES DESC LIMIT 10;

17、查询从未使用过的索引

--从未使用过的索引：未使用索引建议直接删除，多余索引如不使用会影响增删改性能，且索引占用磁盘空间。
select * from schema_unused_indexes where object_schema not in ('performance_schema');

18、查询冗余索引

--冗余索引建议删除
select * from schema_redundant_indexes;

19、查询数据库中没有主键的表

--查询所有无主键表：
SELECT A.table_schema, A.table_name FROM information_schema.tables AS A LEFT JOIN (SELECT table_schema, table_name FROM information_schema.statistics WHERE index_name = 'PRIMARY') AS B ON A.table_schema = B.table_schema AND A.table_name = B.table_name WHERE A.table_schema NOT IN ('information_schema' , 'mysql','performance_schema', 'sys') AND A.table_type='BASE TABLE' AND B.table_name IS NULL;

20、查询非InnoDB表

--非innodb表
SELECT table_schema,table_name,engine FROM information_schema.tables where table_schema not in ('mysql','sys','information_schema','performance_schema') and engine!='InnoDB';

21、查询从库状态信息（主从状态，延迟）

--主从状态: (Slave_IO_Running和Slave_SQL_Running 都为YES 且Seconds_Behind_Master 为0)
show slave status\G
*************************** 1. row ***************************Slave_IO_State: Waiting for master to send eventMaster_Host: 10.120.184.82Master_User: repuserMaster_Port: 3306Connect_Retry: 5Master_Log_File: mysql-bin.001026Read_Master_Log_Pos: 182832Relay_Log_File: mysql-relay-bin.002069Relay_Log_Pos: 183005Relay_Master_Log_File: mysql-bin.001026Slave_IO_Running: YesSlave_SQL_Running: YesReplicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0Last_Error: Skip_Counter: 0Exec_Master_Log_Pos: 182832Relay_Log_Space: 183299Until_Condition: NoneUntil_Log_File: Until_Log_Pos: 0Master_SSL_Allowed: NoMaster_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: NoLast_IO_Errno: 0Last_IO_Error: Last_SQL_Errno: 0Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 330682Master_UUID: d2ba61a0-5b46-11ee-b627-005056b51543Master_Info_File: mysql.slave_master_infoSQL_Delay: 0SQL_Remaining_Delay: NULLSlave_SQL_Running_State: Slave has read all relay log; waiting for more updatesMaster_Retry_Count: 86400Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: d2ba61a0-5b46-11ee-b627-005056b51543:12832492-14068377Executed_Gtid_Set: a5bf5226-5b48-11ee-ae63-005056b53ab2:1,
d2ba61a0-5b46-11ee-b627-005056b51543:1-14068377Auto_Position: 1Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version:

22、查看慢日志信息：是否开启及慢日志的位置

--确认慢日志是否开启：slow_query_log为ON 及慢日志位置：/data/mysql8036/3306/logs/slow.log
root@localhost:sys 04:14:14 >show global variables like 'slow%';
+---------------------+------------------------------------+
| Variable_name       | Value                              |
+---------------------+------------------------------------+
| slow_launch_time    | 2                                  |
| slow_query_log      | ON                                 |
| slow_query_log_file | /data/mysql8036/3306/logs/slow.log |
+---------------------+------------------------------------+
3 rows in set (0.00 sec)--确认慢日志记录的时间阈值：
root@localhost:sys 04:14:16 >show global variables like 'long%';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 1.000000 |
+-----------------+----------+
1 row in set (0.00 sec)