Atomic Protector Installation Recommendations


We reccommend minimum of 16 GB of memory for systems with a high volume of events and/or domains. Modern Linux systems generally perform better with more memory. The Linux kernel will cache file reads, which speeds up the system and other applications will use memory to further speed up their operations. Memory is a cost-effective way to speed up a system.


A minimum of 8 CPUs are highly recommended for systems with a high volume events and/or domains.



If you do not need to allow remote access to MySQL, then we recommend that you configure MySQL to only allow connections from the local host. You can do that by adding the following to /etc/my.cnf:



After making changes to /etc/my.cnf you will need to restart the MySQL service.

Query Caching

When using mysql, querying caching must be enabled. Larger query caches will result in greater performance, however this must be tuned to the capabilities of the system. Larger query caches also require more memory, so to increase this setting you will need at least 8GB of RAM and preferably 16GB of RAM or more.

For example, on a system with 2GB of RAM the query cache should be set to 128M.


For systems with 4GB of RAM, or more, a large query cache can be used:


While larger cache sizes can be tried, 128m is as high as it is neccesary to go. High values may be counter productive.

Dedicated I/O Channel

For systems with high volumes of events we recommend you move your mysql databases to their own I/O channel separate from your web sites and/or other file system intensive operations. This will give the database its own dedicated I/O channel to the database files. Databases can be quite large, and the AP events database will grow over time based on the archive settings you have configured in your AP Configuration. Therefore, a faster way of reading these databases will improve performance on the system.

MySQL Tuning

If you are using mysql, we highly recommend you tune it with a professionals help. mysql is a wonderful and powerful database server, but it is not tuned in its default configuration and will perform very poorly as a result. Even if mysql appears to be performing well for you, if you are using the default settings your database server is operating much slower than it needs to be.

You can use the excellent tool mysqltuner to help with this, however this tool will just provide recommendations and an experts assistance should be consulted before making any changes to your mysql configuration, and to make the best use of the recommendations mysqltuner may provide.

To install mysqltuner, please follow the steps below:

  1. Run the following command:

    yum install mysqltuner
  2. To start mysqltuner run the following command:


For more information about mysqltuner, please go here