Because of log_slow_rate_limit there is a 1/1000 chance that a slow query won't be logged.
Is there anything in the mysql error log (`journalctl -u mariadb.service`) about not being able to create the file? What is the permission on /var/log/mysql/? If you lsof -p $(pidof mysqld) | grep /var/log is the slow query log there? Does it have '(deleted)' on that same line (which would indicate a logrotate problem)?
Hi Daniel
Thanks for your reply
mysql error log has no relative errors:
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Using mutexes to ref count buffer pool pages |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: The InnoDB memory heap is disabled |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Compressed tables use zlib 1.2.11 |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Using Linux native AIO |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Using SSE crc32 instructions |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Initializing buffer pool, size = 4.0G |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Completed initialization of buffer pool |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Highest supported file format is Barracuda. |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: 128 rollback segment(s) are active. |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Waiting for purge to start |
2019-03-05 2:23:34 140593162477504 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.6.36-82.2 started; log sequence number 14517640669 |
2019-03-05 2:23:34 140593162477504 [Note] Plugin 'FEEDBACK' is disabled. |
2019-03-05 2:23:34 140587967706880 [Note] InnoDB: Dumping buffer pool(s) not yet started |
2019-03-05 2:23:34 140593162477504 [Note] Server socket created on IP: '10.8.96.4'. |
2019-03-05 2:23:34 140593162477504 [Note] /usr/sbin/mysqld: ready for connections. |
Version: '10.1.29-MariaDB-6ubuntu2' socket: '/var/run/mysqld/mysqld.sock' port: 3306 Ubuntu 18.10 |
2019-03-05 2:23:34 140593103030016 [Warning] IP address '10.8.96.3' could not be resolved: Name or service not known |
/var/log/mysql's permission is ok I think:
drwxr-s--- 2 mysql adm 4096 Mar 5 02:12 mysql/ |
db01@/var/log/mysql$ lsof -p $(pidof mysqld) | grep /var/log
|
mysqld 31974 mysql 1w REG 252,1 5447 264178 /var/log/mysql/error.log |
mysqld 31974 mysql 2w REG 252,1 5447 264178 /var/log/mysql/error.log |
mysqld 31974 mysql 44w REG 252,1 1098 256079 /var/log/mysql/mariadb-slow.log |
and you said "Because of log_slow_rate_limit there is a 1/1000 chance that a slow query won't be logged."
But in status command ,I can see hundreds slow queries, but in slow query log,there is nothing at all TAT
With log_slow_rate_limit=1000, only one query out of 1000 is logged.