Create a new Pentaho Analyzer report and drag a measure or a dimension in the report. Once your report is displaying numbers, click on the top link, identified as "Log". If 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.
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.