Default Parameters for MySQLSlowLgTest

In general, as applications scale in size, queries to the database server that were once extremely fast can become quite slow. When you are debugging a MySQL database server instance for performance issues, the slow query log comes in handy to figure out which queries are the slowest and how often they are slow.

A query is deemed to be slow and is logged in the slow query log if that query exceeds a given threshold of execution time. By default, all queries taking longer than 10 seconds are logged. If the queries are repeatedly logged in the slow query log, then, the size of the log may grow rapidly leading to an impact on the performance of the database server instance. To improve the performance of the database server instance, it is necessary for the administrators to identify the slow queries and optimize them at the earliest. The MySQLSlowLgTest test helps administrators to proactively track such abnormalities in the slow query log and optimize the queries before end users start complaining.

This test periodically monitors the slow query log of the target database server and reports whether/not the slow query log is enabled. This test also reports the total file size of the slow query log and the growth rate of the log file. Using this test, administrators can quickly determine abnormal growth patterns of the slow query log and identify those slow queries that are candidates for optimization.

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

• The TEST PERIOD list box helps the user to choose how often should the test be executed.

• In the DATABASE text box specify the name of a database on the target MySQL database server being monitored.

• 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. Specify the credentials of such a user in the USERNAME and PASSWORD text boxes. To know how to create such a user, refer to Pre-requisites for Monitoring the MySQL Server topic in the Monitoring MySQL Server document.

• Confirm the password by retyping it in the CONFIRM PASSWORD text box.

• In the SLOW QUERY TIME text box, specify the duration (in seconds) beyond which a query (logged in slow query log) should have executed for it to be considered as a slow query by this test. The default value is 10 seconds.

• Once the above values are provided, click on the UPDATE button to 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.