Configuring MariaDB for Optimal Performance

Complete MariaDB performance tuning: innodb_buffer_pool_size, aria_pagecache_buffer_size, thread_handling configuration, and SHOW GLOBAL STATUS monitoring.

This article will help you configure MariaDB for optimal performance.

By default, MariaDB is configured to work on a desktop system and therefore use relatively few resources. To optimize installation for a dedicated server, you have to do a few minutes of work.

For this article we assume that you are going to run MariaDB on a dedicated server.

Feel free to update this article if you have more ideas.

my.cnf Files

MariaDB is normally configured by editing the my.cnf file. In the next section you have a list of variables that you may want to configure for dedicated MariaDB servers.

InnoDB Storage Engine

InnoDB is normally the default storage engine with MariaDB.

• You should set innodb_buffer_pool_size to about 80% of your memory. The goal is to ensure that 80 % of your working set is in memory.

The other most important InnoDB variables are:

• innodb_log_file_size

• innodb_flush_method

• innodb_thread_sleep_delay

Some other important InnoDB variables:

• innodb_max_dirty_pages_pct_lwm

• innodb_read_ahead_threshold

• innodb_buffer_pool_instances. Deprecated and ignored from MariaDB 10.5.1.

• innodb_adaptive_max_sleep_delay. Deprecated and ignored from MariaDB 10.5.5.

• innodb_thread_concurrency. Deprecated and ignored from MariaDB 10.5.5.

Aria Storage Engine

• MariaDB uses by default the Aria storage engine for internal temporary files. If you have many temporary files, you should set aria_pagecache_buffer_size to a reasonably large value so that temporary overflow data is not flushed to disk. The default is 128M.

You can check if Aria is configured properly by executing:

MariaDB [test]> show global status like "Aria%";

+-----------------------------------+-------+
| Variable_name                     | Value |
+-----------------------------------+-------+
| Aria_pagecache_blocks_not_flushed | 0     |
| Aria_pagecache_blocks_unused      | 964   |
| Aria_pagecache_blocks_used        | 232   |
| Aria_pagecache_read_requests      | 9598  |
| Aria_pagecache_reads              | 0     |
| Aria_pagecache_write_requests     | 222   |
| Aria_pagecache_writes             | 0     |
| Aria_transaction_log_syncs        | 0     |
+-----------------------------------+-------+

If Aria_pagecache_reads is much smaller than Aria_pagecache_read_request andAria_pagecache_writes is much smaller than Aria_pagecache_write_request#, then your setup is good. If the aria_pagecache_buffer_size is big enough, the two variables should be 0, like above.

MyISAM

• If you don't use MyISAM tables explicitly (true for most MariaDB 10.4+ users), you can set key_buffer_size to a very low value, like 64K.

Using in memory temporary tables

Using memory tables for internal temporary results can speed up execution. However, if the memory table gets full, then the memory table will be moved to disk, which can hurt performance.

You can check how the internal memory tables are performing by executing:

MariaDB [test]> show global status like "Created%tables%";

+-------------------------+-------+
| Variable_name           | Value |
+-------------------------+-------+
| Created_tmp_disk_tables | 1     |
| Created_tmp_tables      | 2     |
+-------------------------+-------+

Created_tmp_tables is the total number of internal temporary tables created as part of executing queries like SELECT.Created_tmp_disk_tables shows how many of these did hit the storage.

You can increase the storage for internal temporary tables by setting max_heap_table_size and tmp_memory_table_size high enough. These values are per connection.

Lots of Connections

A Lot of Fast Connections + Small Set of Queries + Disconnects

• If you are doing a lot of fast connections / disconnects, you should increase back_log and if you are running MariaDB 10.1 or below thread_cache_size.

• If you have a lot (> 128) of simultaneous running fast queries, you should consider setting thread_handling to pool_of_threads.

Connecting From a Lot of Different Machines

• If you are connecting from a lot of different machines you should increase host_cache_size to the max number of machines (default 128) to cache the resolving of hostnames. If you don't connect from a lot of machines, you can set this to a very low value!

See Also

• MariaDB Memory Allocation

• Full List of MariaDB Options, System and Status Variables

• Server system variables

• mysqld options

• Performance schema helps you understand what is taking time and resources.

• Slow query log is used to find queries that are running slow.

• OPTIMIZE TABLE helps you defragment tables.

External Links

• what-to-tune-in-mysql-56-after-installation.html

• optimizing-mysql-configuration-percona-mysql-university-montevideo

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