Expose performance counters for the standalone database. Add options to the Journal to enable: (a) performance counter collection every 60 seconds; and (b) an httpd service which may be used to query the last 60 minutes worth of performance counter data. Provide a version of the Excel worksheet which may be used to query the httpd service and demonstrates how to extract various performance counters of interest. When performance counter collection is enabled, log the counters against a log4j logger with a plain format and a FileAppender or RollingDailyFileAppender at the INFO level. Ensure that counters are reported from the Journal for the backing store, the indices, and the operating system (Unix or Windows). Gracefully handle cases where pidstat is not available / found since it is much less common to find sysstat installed and the database should start regardless. Likewise, a failure to start typeperf or vmstat should not prevent correct functioning of the database. Provide online documentation for the performance counters and a guide to diagnosing performance problems.