The following are examples of running j_stat.d. j_stat.d shows you the number of events per second that have happened since the last line output. The default interval is 1 second, but you can specify other intervals as arguments to the script. This shows the j_stat.d script reflecting the Code/Ruby/Func_abc script. # j_stat.d TIME EXEC/s THREAD/s METHOD/s OBJNEW/s CLOAD/s EXCP/s GC/s 2007 Sep 24 04:00:34 0 0 0 0 0 0 0 2007 Sep 24 04:00:35 2 6 11660 5306 318 41 0 2007 Sep 24 04:00:36 0 0 124 4 0 2 0 2007 Sep 24 04:00:37 0 0 124 4 0 2 0 2007 Sep 24 04:00:38 0 0 123 75 9 1 0 2007 Sep 24 04:00:39 0 0 0 0 0 0 0 2007 Sep 24 04:00:40 0 0 0 0 0 0 0 ^C Here we can see that at 2007 Sep 24 04:00:35 there were 2 Java programs executed, (this number will include those without Java provider support), there were 6 threads created, 11,660 methods called, 5306 new objects created, 318 class loads, 41 exceptions raised and no garbage collects. The numbers are per second counts for the interval specified. The default interval is 1 second. If you see a count in "EXECS" but not in the other columns, then your Java software is probably not running with the DTrace hotspot provider. If you see counts in "CLOAD" but not in "METHODS", then you Java software probably isn't running with "+ExtendedDTraceProbes".