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.
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 |
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:
|
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. |