Configuration of 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.

The default parameters associated with this test are:

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

• In the HOST text box, specify the IP address of the host for which the test is to be configured.

• In the PORT text box, specify the port at which the specified host listens.

• 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.

• The DETAILED DIAGNOSIS makes diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option. The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability

  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0

• If multiple components of the same component type are awaiting configuration, then an APPLY TO OTHER COMPONENTS check box will appear in this page. Clicking on this check box will allow you to apply the configuration to all/selected components of that type.

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

When changing the configuration for specific servers, a “*” beside the text box corresponding to the parameter signifies that these values have to be manually configured by the user. The parameter values that require to be configured will typically be prefixed with a “$” or contain a series of “*”. A value of “none” in the parameter value indicates that the corresponding parameter value can be changed if required.