WAS v8.5 > Monitoring > Monitoring overall system health > Monitoring performance with Tivoli Performance Viewer

Logging performance data with Tivoli Performance Viewer

The Tivoli Performance Viewer can store real-time data for system resources, WebSphere Application Server pools and queues, and applications in log files for later retrieval. We can start and stop logging while viewing current activity for a server, and later replay this data. Logging of performance data captures performance data in windows of time so we can later analyze the data.

This article assumes you have configured the Tivoli Performance Viewer log settings. The log settings may affect performance and are described in detail in View Data with the Tivoli Performance Viewer. The Tivoli Performance Viewer logging feature is not intended to be a full-time monitoring solution, but instead for selective data recording for subsequent replay and analysis. We can study the sequence of events that led to a peculiar condition in the application server.

First, enable Tivoli Performance Viewer logging so performance data generated in the application server persists in a log file stored at a specific location. Later, using the replay feature in Tivoli Performance Viewer, view the performance data that was generated in exactly the same chronological order as it was generated in real time, enabling you to analyze a prior sequence of events.

We do not need to know the syntax and format in which log files are generated and stored. Do not edit log files generated by Tivoli Performance Viewer; doing so will irrecoverably corrupt or destroy the performance data stored in the log files.

We can create and view logs in the dmgr console.

Create logs

  1. Click...

      Monitoring and Tuning | Performance Viewer | Current Activity | server_name | Settings | Log

  2. Click on Start Logging when viewing summary reports or performance modules.

  3. When finished, click Stop Logging . Once started, logging stops when the logging duration expires, Stop Logging is clicked, or the file size and number limits are reached. To adjust the settings, see step 1.

View logs

  1. Click...

      Monitoring and Tuning | Performance Viewer | View Logs

  2. Select a log file to view using either of the following options:

    Explicit Path to Log File

    Choose a log file from the machine on which the browser is currently running. Use this option if you have created a log file and transferred it to the system. Click Browse to open a file browser on the local machine and select the log file to upload.

    Server File

    Specify the path of a log file on the server.

  3. Click View Log. The log is displayed with log control buttons at the top of the view.

  4. Adjust the log view as needed. Buttons available for log view adjustment are described below. By default, the data replays at the Refresh Rate specified in the user settings. Choose one of the Fast Forward modes to play data at rate faster than the refresh rate.

    Button Description
    Rewind Returns to the beginning of the log file.
    Stop Stops the log at its current location.
    Play Begins playing the log from its current location.
    Fast Forward Loads the next data point every three (3) seconds.
    Fast Forward 2 Loads ten data points every three (3) seconds.

We can view multiple logs at a time. After a log has been loaded, return to the View Logs panel to see a list of available logs. At this point, we can load another log.

Tivoli Performance Viewer automatically compresses the log file when finishes writing it. The log does not need to be decompressed before viewing it, though Tivoli Performance Viewer can view logs that have been decompressed.