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Pentaho Documentation

OLAP Log Output

Parent article

The Pentaho Server and the standalone Mondrian engine both use log4j to record information about generated OLAP-generated SQL queries. It may be useful to examine this log output if you are having trouble with configuration or performance-tuning.

Analysis SQL output logging

You can log SQL generation in the Pentaho Server or Mondrian engine.

Follow the directions below to turn on this SQL logging. If you are aware of other log4j classes that will assist you in configuration troubleshooting or performance-tuning, you can add them during this process.

Procedure

  1. Stop the Pentaho Server or standalone Mondrian engine.

  2. Edit the log4j.xml file in the /WEB-INF/classes/ directory inside of the deployed pentaho.war or Mondrian engine.

    NoteIn some Mondrian implementations, this file is log4j.properties. Substitute this filename accordingly if you do not see a log4j.xml file.
  3. Add the following line anywhere inside of the </log4j:configuration> node (but not inside of other constituent node tags):

    log4j.logger.mondrian.sql=DEBUG
  4. Save and close the file.

  5. Start the Pentaho ServerPentaho Server or Mondrian engine.

Results

A significant amount of Analysis SQL query debugging information will now be available in your application server's logs. Some data about the segment cache plugin will also appear, but there are some other steps to take beyond this if you want log data specific to the segment cache. Refer to Enabling segment cache logging for more information

Enabling segment cache logging

The Pentaho Server allows you to view engine segment cache logs by opening the log window from within Analyzer.

If you are using Analyzer with a standalone Mondrian engine, cache log information is available through log4j. Edit your log4j configuration as explained in Analysis SQL Output Logging, and set the value of com.pentaho.analysis.segmentcache to DEBUG. The table below lists other log4j categories that can help you diagnose configuration and performance problems.

Class NameCache System
com.pentaho.​analysis.segmentcache.​impl.infinispanOutputs information related to the Infinispan implementation of the segment cache.
com.pentaho.​analysis.segmentcache.​impl.memcachedOutputs information related to the Memcached implementation of the segment cache.
com.pentaho.​analysis.segmentcache.​impl.pentahoOutputs information related to the Pentaho BI Platform Delegating Cache implementation.

View Log Output in Analyzer

You can view the log in Analyzer.

Perform the followuing actions to view the log in Analyzer:

Procedure

  1. Create a new Pentaho Analyzer report and drag a measure or a dimension in the report.

  2. Once your report is displaying numbers, click on the top link, identified as More actions and options, and choose Administration Log item.

    How to View the Log Output in Analyzer

    NoteIf there is no such link available within Pentaho Analyzer, it is because you have not used an administrator account to login to Pentaho User Console. You must log out and log back in using an administrator account credentials.

Results

If your plugin was successfully configured, you should see log information relating to the segment cache. If there was an error in your configuration, all exception messages will be displayed here as well.