Henk Vandenbergh

NullPointerException running Multi-host Vdbench501

Two new problems were discovered last week, both resulting in a NullPointerException.

With the first one, four hosts were defined, but only three were used.Vdbench was trying to print a 'rd started' message on the device reports for that host, but of course no devices were busy. Just remove the unused host to get around this problem.

The second one was caused by the way Vdbench calculates the amount of JVM's needed. Normally that is one JVM per SD per 5000 iops, with a max of eight. This run had 4 SDs per host for a total of 16. Vdbench should have taken multi-host into consideration here, but did not. The resulting eight JVMs per host then caused the first JVM (slave 0) on a host not to have any work to do. Since slave 0 on each host is responsible for collection Kstat statistics and slave 0 was idle, no Kstat data was returned causing the NULLPointerException. You can work around this problem by either specifying '-m4' as an execution parameter, or adding 'hd=default,jvms=4' as you first Host Definition.

Henk.

Posted at 08:15AM Sep 28, 2009 by Henk Vandenbergh in Sun  |  Comments[0]