MariaDB Best practices for Optimization & Tuning

InnoDB file-per-table

InnoDB Buffer Pool Size

Max Connections

Disable Swap In MySQL

Tune Your Table Cache

How to deal Query Cache

Tune/Increase Open Files Limit

InnoDB file-per-table

After setting this parameter all the tables will have their own .idb file on server

innodb_file_per_table=1

MariaDB 10.x, innodb_file_per_table=1 is a default setting. if so your new InnoDB tables and those converted from MyISAM to InnoDB will already have separate tablespaces.

if you are using MariaDB 5.5, innodb_file_per_table=0 by default. 

To start using individual tablespaces, run SET GLOBAL innodb_file_per_table = 1;

To make the option permanent, add it to the cnf file.

InnoDB Buffer Pool Size

We can set the parameter to 60 percent of your memory

The default value of Buffer pool size is 8MB and you can change this value by adding the following line in your my.cnf file

innodb_buffer_pool_size = 1G

Disable Swap In MySQL  

Max Connections

Tune Your Table Cache 

SHOW GLOBAL STATUS LIKE 'Open%table%';

For table_open_cache, it shall be the total number of your tables

 but it's best you add more depending on the type of queries you serve since temporary tables shall be cached as well.

 For example, if you have 500 tables, it would be reasonable you start with 1500. 

While your table_open_cache_instances, start setting it to 8. 

This can improve scalability by reducing contention among sessions, 

the open tables cache can be partitioned into several smaller cache instances of size table_open_cache / table_open_cache_instances.

Dealing with Query Cache

Preferred option -  We think that disabling the query cache to improve the performance of MariaDB is the preferred option. 

You need to make sure that query_cache_type=OFF and query_cache_size=0 so that the query cache is completely disabled. 

In contrast to MySQL, MariaDB still supports query cache and doesn’t plan to withdraw support for it anytime soon.

There are those who think that using query cache gives them performance benefits,

but as this post from Percona demonstrates, 

an enabled query cache increases overhead and reduces server performance.

If you want to use query cache, ensure that you monitor it by running 

SHOW GLOBAL STATUS LIKE ‘Qcache%’;. 

Qcache_inserts reports on how many queries have been added to the query cache,

Qcache_hits shows how many have made use of it, and 

Qcache_lowmem_prunes contains the number of queries that have been dropped because of insufficient memory. 

Over time, using query cache may cause it to become fragmented.

A high Qcache_free_blocks to Qcache_total_blocks ratio may point to increased fragmentation. 

To defragment it, run FLUSH QUERY CACHE. This will defragment the query cache without dropping any queries and improve MariaDB performance.

Tune/Increase Open Files Limit

To ensure good server performance, the total number of client connections, database files, and log files must not exceed the maximum file descriptor limit on the operating system (ulimit -n). Linux systems limit the number of file descriptors that any one process may open to 1,024 per process. On active database servers (especially production ones) it can easily reach the default system limit.

To increase this, edit /etc/security/limits.conf and specify or add the following:

1 mysql soft nofile 65535

2

3 mysql hard nofile 65535

 

This requires a system restart. Afterwards, you can confirm by running the following:

1 $ ulimit -Sn

2

3 65535

4

5 $ ulimit -Hn

6

7 65535

 

 

Optionally, you can set this via mysqld_safe if you are starting the mysqld process thru mysqld_safe,

1 [mysqld_safe]

2

3 open_files_limit=4294967295

or if you are using systemd,

1 sudo tee /etc/systemd/system/mariadb.service.d/limitnofile.conf <<EOF

2 

3 [Service]

4

5 LimitNOFILE=infinity

6

7 EOF

8 

9 sudo systemctl daemon-reload