Introducing performance monitoring

Performance Monitoring:

The information gathered by the Performance Monitor can be used to:

The Performance Monitor uses monitors to monitor the performance of DB2 Universal Database. Monitors specify many things including the interval between samples, the types of objects to be monitored, and the information categories (or performance variables) to be turned on or off for each type of object. For the categories that are turned on, the monitor profile can specify an upper and a lower alarm threshold for each measured element, and the action to be taken when each element exceeds its upper and lower threshold (for example, run a script, issue an audible alarm, or send a message). There are 2 types of monitors, IBM supplied predefined monitors and monitors that you create yourself. For more information on IBM supplied predefined performance monitors, click here.



Below is an example of how you might set up performance monitoring at the database level to find the cause of a performance problem. This is only one possible example of how performance monitoring can be used, there are many other possible ways which are not described here.

To start monitoring the performance of a database, you will need to do the following:

To set up performance monitoring at the database level:

The following example shows what you might do if you suspect that your database performance is poor. This example looks at monitoring disk performance.

  1. Select the DISK_PERFORMANCE monitor (an IBM supplied predefined monitor). The DISK_PERFORMANCE monitor monitors input and output. It contains performance variables that focus on disk performance at the Database and Tablespace level. For descriptions of IBM supplied predefined monitors click here.

    1. Open the List Monitors window.

    2. In the List Monitors window, select the DISK_PERFORMANCE monitor.

  2. Copy the DISK_PERFORMANCE monitor so that you own it.

    1. Open the List Monitors window.

    2. Select the DISK_PERFORMANCE monitor.

    3. Click Copy. The Copy Monitor window opens.

    4. Copy the monitor

    5. Once the monitor has been copied it appears in the List Monitors window.

  3. Now that you have copied the monitor, you can modify it so that it will focus on the specific areas that deal with the problem area in your database. These modifications are optional and can be made from the Change Monitor notebook. To modify your newly created monitor:

    1. From the List Monitors window, highlight your newly created monitor and click Change. The Change Monitor notebook opens.

    2. In the Change Monitor notebook, performance variables can be added or removed to focus the monitor on your performance problem. To decide which performance variables pertain to the area of your database that you want to monitor, you can refer to the list of performance variables which contains descriptions for each performance variable.

      1. View the performance variables that are in your monitor using the What page of the Change Monitor notebook.

      2. Add any performance variables pertaining to the problem area in your database.

      3. Remove any performance variables not pertaining to the problem area in your database.

    3. For Each Performance Variable that you want to appear on the Details graph in the Show Monitor notebook, select that performance variable and click Graph.

    4. Set the necessary thresholds for your monitor.

    5. When you have made all the necessary changes to your monitor, click OK and the Change Monitor notebook will close. Your new monitor is now set up.

  4. Start your newly created monitor on the database object that you want to monitor.

  5. Click Refresh in the List Monitors window. The status column in the List monitors window now shows the status of your monitor as started. This is a good way to confirm that your monitor has started.

  6. To determine where the problem is in your database, you will need to view the information gathered by the Performance Monitor and analyze it. This information can be viewed from the Show Monitor notebook.

    1. Open the Show Monitor notebook.

    2. Select your newly created monitor from the Monitor name drop down in the Show Monitor notebook.

    3. View the information that your performance monitor has collected for objects at a selected point in time from the Details page of the Show Monitor notebook.

    4. If you have selected performance variables to appear on the Details graph, you will be able to view the Details graph in the Graph page of the Show Monitor notebook. Note: From the Show Monitor notebook you can make changes to your monitor while it is active.

    5. Analyze the information that your Performance Monitor has collected and use the data to solve your problem. Once you have implemented a change to the database, run the Performance Monitor again to see what effect your change has had on database operation.


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