Default Parameters for MySQLTemTabStTest

In MySQL, a temporary table is a special type of table that allows you to store a temporary result set, which you can reuse several times in a single session. In some cases, the server creates internal temporary tables while processing statements. Users have no direct control over when this occurs. If an internal temporary table is created as an in-memory table but becomes too large, MySQL automatically converts it to an on-disk table. The maximum size for in-memory temporary tables is the minimum of the tmp_table_size and max_heap_table_size. If the result set gets bigger than this threshold, MySQL will overflow to-disk based temporary tables. When the size of on-disk temp tables increases beyond threshold, it can cause disk space exhaustion leading to server outages. Because of the continuous outages of the service, the user has to constantly restart the server leading to poor user experience. MySQLTemTabStTest helps administrators in this regard.

This test continuously tracks the total and maximum number of temporary tables created on disk and alerts administrators when the size of the on-disk temporary tables increases beyond the threshold. This way, administrators can be proactively alerted to increasing size of the on-disk temporary tables and thus enabled to rapidly initiate remedial measures to avoid an impending server outage.

This page depicts the default parameters that need to be configured for the MySQLTemTabStTest.

• The TEST PERIOD list box helps the user to decide how often this test needs to be executed.

• Specify the name of a database on the target MySQL database server being monitored in the DATABASE textbox.

• The eG agent has to be configured with the credentials of a user who has server-wide Process and Select privileges on the monitored MySQL server. To know how to create such a user, refer to Configuring the eG Agent with Access Privileges topic. Specify the credentials of such a user in the USERNAME and PASSWORD textboxes.

• Confirm the password by retyping it in the CONFIRM PASSWORD textbox.

• By default, the detailed diagnosis of this test, if enabled, will report only the top-10 tables. This is why, the DD ROW COUNT parameter is set to 10 by default. If you want to include more or less tables in detailed diagnosis, then change the value of this parameter accordingly.

• Once the necessary values have been provided, clicking on the UPDATE button will register the changes made.

When changing default configurations of tests, the values with “$” indicate variables that will be replaced by the eG system according to the specific server being managed - for instance, $hostName is the host/nickname of the target host, $port is the port number of the server being monitored. E.g., for a server xyz:80, $hostName will be changed automatically by the eG manager to “xyz*” and $port will be changed to “80” when configuring a test.