# Handling slow log with suffixes (with max\_slowlog\_size and max\_slowlog\_files) **URL:** \ **Category:** PMM 2.x\ **Created:** [September 29, 2020, 9:52am UTC](https://forums.percona.com/t/handling-slow-log-with-suffixes-with-max-slowlog-size-and-max-slowlog-files/8089 "2020-09-29T09:52:19Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![babine](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/babine/32/4_2.png) [@babine](https://forums.percona.com/u/babine)\ **Post date:** [September 29, 2020, 9:52am UTC](https://forums.percona.com/t/handling-slow-log-with-suffixes-with-max-slowlog-size-and-max-slowlog-files/8089/1 "2020-09-29T09:52:19Z")
Hello, There is an option in Percona server to automatically rotate slow logs, namely max\_slowlog\_size and max\_slowlog\_files. As per the documentation, we only specify the prefix in the slow\_query\_log\_file variable and then numbered suffixes are added : > For this feature to work variable slow\_query\_log\_file needs to be set up manually and without the .log sufix. The slow query log files will be named using slow\_query\_log\_file as a stem, to which a dot and a sequence number will be appended. It seems that when using this functionnality PMM client seems to struggle to find the slowlog because it searches for the slowlog name without the suffix. In my case : PMM server v2.10.0 PMM client 2.9.1-6.stretch (debian package) Server : 5.7.29-32-log Percona Server (GPL), Release 32, Revision 56bce88 ```auto mysql> show variables like '%slow%'; +-----------------------------------+-----------------------------------------------------------------------------------------------+ | Variable_name | Value | +-----------------------------------+-----------------------------------------------------------------------------------------------+ | log_slow_admin_statements | ON | | log_slow_filter | | | log_slow_rate_limit | 1 | | log_slow_rate_type | session | | log_slow_slave_statements | ON | | log_slow_sp_statements | ON | | log_slow_verbosity | microtime,query_plan,innodb | | max_slowlog_files | 6 | | max_slowlog_size | 268435456 | | slow_launch_time | 2 | | slow_query_log | ON | | slow_query_log_always_write_time | 1800.000000 | | slow_query_log_file | /var/lib/mysql/data/servername-slow | | slow_query_log_use_global_control | log_slow_filter,log_slow_rate_limit,log_slow_verbosity,long_query_time,min_examined_row_limit | +-----------------------------------+-----------------------------------------------------------------------------------------------+ ``` PMM client status : ```auto # pmm-admin list Service type Service name Address and port Service ID MySQL servername-mysql /tmp/mysql.sock /service_id/a357f4d6-d33b-43f8-b6ce-6a7963044650 Agent type Status Agent ID Service ID pmm_agent Connected /agent_id/6cd13230-e2f7-4aa2-923a-ddf9fa5a4afc node_exporter Running /agent_id/2d47fef9-fdc2-46e8-859c-0704cb71b2cd mysqld_exporter Running /agent_id/506c0710-4e1c-40ac-a4e4-9e8ab090c496 /service_id/a357f4d6-d33b-43f8-b6ce-6a7963044650 mysql_slowlog_agent Waiting /agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 /service_id/a357f4d6-d33b-43f8-b6ce-6a7963044650 ``` If I check on the server I have the following slow log : ```auto # ls -al /var/lib/mysql/data/servername-slow* -rw-r----- 1 mysql mysql 249741292 Sep 29 17:16 /var/lib/mysql/data/servername-slow.000003 ``` But in the log I find this error : ```auto syslog:Sep 29 16:37:11 servername pmm-agent[31010]: #033[36mINFO#033[0m[2020-09-29T16:37:11.955+02:00] Processing file /var/lib/mysql/data/servername-slow. #033[36magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[36mcomponent#033[0m=agent-builtin #033[36mtype#033[0m=qan_mysql_slowlog_agent syslog:Sep 29 16:37:11 servername pmm-agent[31010]: #033[31mERRO#033[0m[2020-09-29T16:37:11.956+02:00] Failed to start reader for file /var/lib/mysql/data/servername-slow: open /var/lib/mysql/data/servername-slow: no such file or directory. #033[31magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[31mcomponent#033[0m=agent-builtin #033[31mtype#033[0m=qan_mysql_slowlog_agent syslog:Sep 29 16:37:11 servername pmm-agent[31010]: #033[36mINFO#033[0m[2020-09-29T16:37:11.956+02:00] Sending status: STARTING. #033[36magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[36mcomponent#033[0m=agent-builtin #033[36mtype#033[0m=qan_mysql_slowlog_agent syslog:Sep 29 16:37:11 servername pmm-agent[31010]: #033[36mINFO#033[0m[2020-09-29T16:37:11.956+02:00] Sending status: WAITING. #033[36magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[36mcomponent#033[0m=agent-builtin #033[36mtype#033[0m=qan_mysql_slowlog_agent syslog:Sep 29 16:37:14 servername pmm-agent[31010]: #033[31mERRO#033[0m[2020-09-29T16:37:14.545+02:00] Failed to stat file: stat /var/lib/mysql/data/servername-slow: no such file or directory #033[31magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[31mcomponent#033[0m=agent-builtin #033[31mtype#033[0m=qan_mysql_slowlog_agent ``` (And of course nothing shows up in the PMM interface) Am I missing something here ? An option to specify that when registering the MySQL service ? ---
**Author:** ![nailya](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/nailya/32/1184_2.png) [@nailya](https://forums.percona.com/u/nailya)\ **Post date:** [October 2, 2020, 9:23am UTC](https://forums.percona.com/t/handling-slow-log-with-suffixes-with-max-slowlog-size-and-max-slowlog-files/8089/2 "2020-10-02T09:23:48Z")
Hi @babine ! Thank you for the question! As I see fromyour comment ```auto max_slowlog_files = 6 ``` But I see the only one slow log file “servername-slow.000003”. Can it be possible that others files were somehow removed by you or someone else? ---
**Author:** ![babine](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/babine/32/4_2.png) [@babine](https://forums.percona.com/u/babine)\ **Post date:** [October 2, 2020, 9:48am UTC](https://forums.percona.com/t/handling-slow-log-with-suffixes-with-max-slowlog-size-and-max-slowlog-files/8089/3 "2020-10-02T09:48:21Z")
Yes they were probably deleted at some point during tests or enabling/disabling slow logs (but they will stop to exist anyway at some point in the future when we arrive at 000008). I can create empty files to check if it changes anything but seeing as the error states “stat /var/lib/mysql/data/servername-slow: no such file or directory” it does not seem it is looking for files with numbered suffixes but rather using slow\_query\_log\_file variable as is. I’ll try creating empty files 000001 and 000002 and tell you if it changes something. ---
**Author:** ![babine](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/babine/32/4_2.png) [@babine](https://forums.percona.com/u/babine)\ **Post date:** [October 5, 2020, 8:41am UTC](https://forums.percona.com/t/handling-slow-log-with-suffixes-with-max-slowlog-size-and-max-slowlog-files/8089/4 "2020-10-05T08:41:13Z")
I created empty files just in case : ```auto # ls -al /var/lib/mysql/data/*slow* -rw-r--r-- 1 mysql mysql 0 Oct 5 16:01 /var/lib/mysql/data/servername-slow.000001 -rw-r--r-- 1 mysql mysql 0 Oct 5 16:01 /var/lib/mysql/data/servername-slow.000002 -rw-r----- 1 mysql mysql 291107123 Oct 2 09:17 /var/lib/mysql/data/servername-slow.000003 -rw-r----- 1 mysql mysql 226774898 Oct 5 16:01 /var/lib/mysql/data/servername-slow.000004 ``` Still have the same error : ```auto Oct 5 16:03:51 servername pmm-agent[31010]: #033[36mINFO#033[0m[2020-10-05T16:03:51.378+02:00] Processing file /var/lib/mysql/data/servername-slow. #033[36magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[36mcomponent#033[0m=agent-builtin #033[36mtype#033[0m=qan_mysql_slowlog_agent Oct 5 16:03:51 servername pmm-agent[31010]: #033[31mERRO#033[0m[2020-10-05T16:03:51.378+02:00] Failed to start reader for file /var/lib/mysql/data/servername-slow: open /var/lib/mysql/data/servername-slow: no such file or directory. #033[31magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[31mcomponent#033[0m=agent-builtin #033[31mtype#033[0m=qan_mysql_slowlog_agent Oct 5 16:03:51 servername pmm-agent[31010]: #033[36mINFO#033[0m[2020-10-05T16:03:51.378+02:00] Sending status: STARTING. #033[36magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[36mcomponent#033[0m=agent-builtin #033[36mtype#033[0m=qan_mysql_slowlog_agent Oct 5 16:03:51 servername pmm-agent[31010]: #033[36mINFO#033[0m[2020-10-05T16:03:51.378+02:00] Sending status: WAITING. #033[36magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[36mcomponent#033[0m=agent-builtin #033[36mtype#033[0m=qan_mysql_slowlog_agent Oct 5 16:03:54 servername pmm-agent[31010]: #033[31mERRO#033[0m[2020-10-05T16:03:54.531+02:00] Failed to stat file: stat /var/lib/mysql/data/servername-slow: no such file or directory #033[31magentID#033[0m=/agent_id/ae6424bc-601a-46f3-ae51-d3e4fbd35722 #033[31mcomponent#033[0m=agent-builtin #033[31mtype#033[0m=qan_mysql_slowlog_agent ``` PMM does not seem to support the fact that having these variables (max\_slowlog\_size and max\_slowlog\_files) set up causes the slow log filename(s) to differ from the slow\_query\_log\_file variable. ---
**Author:** ![babine](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/babine/32/4_2.png) [@babine](https://forums.percona.com/u/babine)\ **Post date:** [November 9, 2020, 8:27am UTC](https://forums.percona.com/t/handling-slow-log-with-suffixes-with-max-slowlog-size-and-max-slowlog-files/8089/5 "2020-11-09T08:27:40Z")
Any news on that ? Should I open a bug report somewhere ?