MySQL Session Wait Events Test

This test monitors wait events to reveal the events per wait class, and the average wait time experienced by the events of a class. Using the metrics reported by this test, DBAs can isolate the type of wait events that are occurring frequently on the database server, and how long such events last. Since the wait class reveals the source of the frequent wait events, from here, all the administrator needs to do is perform simple sequence of diagnostics to figure out why events of this type recur on the database server.

Target of the test : A MySQL server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every wait class on the MySQL server monitored.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The IP address of the MySQL server.

Port

The port at which the specified host listens.

Database

Specify the name of a database on the target MySQL database server being monitored

Username and Password

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 Pre-requisites for Monitoring the MySQL Server topic.

Confirm Password

Confirm the password by retyping it here.

DD Row Count

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

Show Explain Plan

By default, this parameter is set to No indicating that the detailed diagnosis of this test will not list the detailed query plan of the root blockers. If you wish to view the detailed query plan for each root blocker reported by this test, then , set this flag to Yes.

Detailed Diagnosis

To make 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.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Average waiting sessions

Indicates the sum of wait times of all wait events of this wait class during this measurement period.

Seconds

 

Number of waiting sessions

This measure indicates the percentage of waits for each wait class during this measurement period.

Number

 

Maximum waiting session

Indicates the maximum time taken by a wait event among all wait events of this wait class during this measurement period.

Seconds

If the value of this measure is unusually high, then you can use the detailed diagnosis of the measure to accurately identify that wait event under the class that has contributed to the increase in wait time.