MySQL tuning
Take this documentation as is, not as a definitive guide to tuning MySQL. A lot of information and knowledge should be read before changing MySQL configuration. The documentation has been created based on experience shared by OpenKM server administrator users.
Useful links should read:
Sample one
Server information
- Virtualized Windows Server 2008
- CPU: Intel Xeon X3470 @2,93GHz
- RAM: 7GB
- JVM settings for Tomcat: -Xms 3072 -Xmx 3072 -XX:PermSize=256m -XX:MaxPermSize=512m
- The repository is 1GB
MySQL my. cnf changes
- innodb_buffer_pool_size=1792M
- innodb_additional_mem_pool_size=16M
- innodb_log_file_size=256M
- innodb_log_buffer_size=8M
Using MySQL server InnoDB engine with the default configuration parameters in my.cnf file can cause a severe performance bottleneck in applications with high database read-write activity. MySQL should have enough RAM to cache the repository and avoid high Disk I/O activity.
The most important parameters are:
- innodb_buffer_pool_size
- innodb_additional_mem_pool_size
- innodb_log_file_size
- innodb_log_buffer_size
According to some database experts, innodb_buffer_pool_size should occupy 70 percent of the RAM of a dedicated database server.
Before changing these values, please read MySQL documentation carefully. Before making any changes, you should ensure that the MySQL server has been stopped correctly (check the server log). Otherwise, the innodb will become corrupted, and the MySQL server won't restart.
Considerations Repository is 1GB, so 1792M is enough RAM for innodb_buffer_pool_size. The larger the repository, the more memory you need to allocate to innodb_buffer_pool_size. Using an x86 MySQL server, you cannot allocate RAM larger than 2GB.
Information collected from OpenKM forum posts.
Sample two
Server information
- CPU: Intel Xeon E5606 @2.13GHz
- RAM: 4GB
- System: Windows server 2008, 64bit
- JAVA_OPTS=-Xms256m -Xmx1024m -XX:PermSize=256m -XX:MaxPermSize=512m -Djava.awt.headless=true -Dfile.encoding=utf-8
- Database size:2.5G
- Repository size:40GB
- 100,000 nodes(folders + documents)
MySQL my.cnf changes
- query_cache_size=0
- table_open_cache=2000
- tmp_table_size=16M
- thread_cache_size=9
- myisam_max_sort_file_size=100G
- myisam_sort_buffer_size=32M
- key_buffer_size=8M
- read_buffer_size=64K
- read_rnd_buffer_size=256K
- sort_buffer_size=256K
- innodb_additional_mem_pool_size=16M
- innodb_log_buffer_size=8M
- innodb_buffer_pool_size=1042M
Results
Before optimization, the login time was about 45-55 seconds, with a lot of hard-disk I/O usage. After the MySQL optimization, login takes about 10 seconds.
With more RAM, getting a higher MySQL buffer and probably better performance will be possible.
Information collected OpenKM Forum post.
