September 2023 - discuss - lists.mariadb.org

centos7 mariadb5.5 -> MariaDB10.3
by Marc 17 Nov '23

17 Nov '23

Ever since I switched from the default included centos mariadb to your repo. The web applications are getting ~1 once a week connection refused or so. I have already scheduled a cron job to restart your server. But still that is not enough. In the previous 10 years or so I never had such issue nor do I have such issues with postgresql. Nothing is in the log file, only the restart. Should such things not be logged by default? How to configure that issues resulting in refusing access or being unable to give access are logged?

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InnoDB durability
by Federico Razzoli 30 Sep '23

30 Sep '23

Recently Laurynas commented this bug and he brought it up on social media: https://bugs.mysql.com/bug.php?id=75519 I was surprised to read thar, from his comments, this 5.6 bug is still in MySQL 8.0. Did anyone test whether it is in MariaDB too? If so, which versions? Thanks, Federico -- Federico Razzoli Vettabase Ltd director & founder, Database Consultant https://vettabase.com federico.razzoli(a)vettabase.com +44 7739 427279 Telegram: federico_razzoli Skype: fede.razzoli The information in this e-mail and any attachments may be confidential. If you received it by mistake, please inform the sender. Unless you are the intended recipient or his/her representative you are not authorised to, and must not, read, copy, distribute, use or retain this message or any part of it.

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RAM/Swap Usage
by roughnecks 14 Sep '23

14 Sep '23

Hello, first time here :) I've got a single db for roundcube and yet after every couple days my swap for mariadb reaches 200MB and over. To be noted that I'm the sole roundcube's user and that even myself prefer using thunderbird, so I only access roundcube from time to time. Is this normal? I'm running debian stable, upgraded from oldstable when it came out and I remember that in bullseye ram usage was just 50MB or so. Thanks, have a nice day. -- roughnecks

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Increasing RAM usage until oom
by Marco Dickert - evolver group 07 Sep '23

07 Sep '23

Hi folks, we experience a RAM issue with MariaDB (version 10.5.19-MariaDB-0+deb11u2-log) on a standard Debian bullseye system. The problem is that over time MariaDB uses more and more RAM, until the kernel's oom-killer terminates it. The server is a VMware guest with 8G RAM, 2G swap and 4 cores. The most important parameter, innodb_buffer_pool_size, is set to 2G. I know this is quite low for this system, but I want to have proof that MariaDB consumes defininitely more RAM than allowed. According to the calculation in this comment [1], the RAM usage shouldn't exceed 4.2G. Here is the result, including the raw configuration values: ``` MariaDB [(none)]> SELECT ROUND( -> ( @@GLOBAL.key_buffer_size -> + @@GLOBAL.query_cache_size -> + @@GLOBAL.tmp_table_size -> + @@GLOBAL.innodb_buffer_pool_size -> + @@GLOBAL.innodb_log_buffer_size -> + @@GLOBAL.max_connections * ( -> @@GLOBAL.sort_buffer_size -> + @@GLOBAL.read_buffer_size -> + @@GLOBAL.read_rnd_buffer_size -> + @@GLOBAL.join_buffer_size -> + @@GLOBAL.thread_stack -> + @@GLOBAL.binlog_cache_size) -> ) / 1024 / 1024, 1) `total MB`; +----------+ | total MB | +----------+ | 4220.0 | +----------+ 1 row in set (0,001 sec) MariaDB [(none)]> SELECT @@GLOBAL.key_buffer_size, @@GLOBAL.query_cache_size , @@GLOBAL.tmp_table_size, @@GLOBAL.innodb_buffer_pool_size , @@GLOBAL.innodb_log_buffer_size, @@GLOBAL.max_connections , @@GLOBAL.sort_buffer_size, @@GLOBAL.read_buffer_size , @@GLOBAL.read_rnd_buffer_size, @@GLOBAL.join_buffer_size , @@GLOBAL.thread_stack, @@GLOBAL.binlog_cache_size \G 1 row in set (0,000 sec) *************************** 1. row *************************** @@GLOBAL.key_buffer_size: 10485760 @@GLOBAL.query_cache_size: 536870912 @@GLOBAL.tmp_table_size: 16777216 @@GLOBAL.innodb_buffer_pool_size: 2147483648 @@GLOBAL.innodb_log_buffer_size: 134217728 @@GLOBAL.max_connections: 512 @@GLOBAL.sort_buffer_size: 2097152 @@GLOBAL.read_buffer_size: 131072 @@GLOBAL.read_rnd_buffer_size: 262144 @@GLOBAL.join_buffer_size: 262144 @@GLOBAL.thread_stack: 299008 @@GLOBAL.binlog_cache_size: 32768 ``` However, MariaDB uses up to 5.4G so far. And it keeps increasing. Last time the oom-killer was invoked, MariaDB used 10G total, and 7.4G rss (given in 4k pages): ``` [Mi Jul 26 16:01:06 2023] Tasks state (memory values in pages): [Mi Jul 26 16:01:06 2023] [ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name ... [Mi Jul 26 16:01:06 2023] [3462912] 10000 3462912 2753196 1895256 20762624 472509 0 mariadbd ... [Mi Jul 26 16:01:06 2023] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/system.slice/mariadb.service,task=mariadbd,pid=3462912,uid=10000 [Mi Jul 26 16:01:06 2023] Out of memory: Killed process 3462912(mariadbd) total-vm:11012784kB, anon-rss:7581024kB, file-rss:0kB,shmem-rss:0kB, UID:10000 pgtables:20276kB oom_score_adj:0 ``` The MariaDB knowledge base [2] says that the problem probably correlates with one of the following options: ``` +----------------------------+----------------------+----------------+ | variable_name | default_value | variable_value | +----------------------------+----------------------+----------------+ | INNODB_IO_CAPACITY_MAX | 18446744073709551615 | 2000 | | QUERY_CACHE_LIMIT | 1048576 | 67108864 | | MAX_CONNECTIONS | 151 | 512 | | TABLE_OPEN_CACHE_INSTANCES | 8 | 7 | | LONG_QUERY_TIME | 10.000000 | 5.000000 | | KEY_BUFFER_SIZE | 134217728 | 10485760 | | QUERY_CACHE_SIZE | 1048576 | 536870912 | | INNODB_LOCK_WAIT_TIMEOUT | 50 | 80 | | INNODB_LOG_BUFFER_SIZE | 16777216 | 134217728 | | HOST_CACHE_SIZE | 128 | 654 | | INNODB_FT_MIN_TOKEN_SIZE | 3 | 2 | | WAIT_TIMEOUT | 28800 | 600 | | INNODB_FAST_SHUTDOWN | 1 | 0 | | INNODB_LOG_FILE_SIZE | 100663296 | 1073741824 | | THREAD_POOL_SIZE | 8 | 4 | | INNODB_BUFFER_POOL_SIZE | 134217728 | 2147483648 | | MAX_ALLOWED_PACKET | 16777216 | 268435456 | | BACK_LOG | 150 | 254 | +----------------------------+----------------------+----------------+ ``` I can't see what setting could probably cause the issue. Some values are Debian defaults. Most of them we set intentionally. Can anyone give a hint on where to look for? Do you need further information? Thanks for any help. [1] https://serverfault.com/a/1020847 [2] https://mariadb.com/kb/en/mariadb-memory-allocation/#how-to-troubleshoot-ou… Regards, Marco

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