Can you please let me know what this exception pointing to under access logs in apache webserver 2.2.7 ?
10.108.30.170 - - [02/Jul/2014:15:07:32 -0500] "CLUSTER-BROADCAST" 500 553
10.108.30.170 - - [02/Jul/2014:15:07:34 -0500] "CLUSTER-BROADCAST" 500 553
10.108.30.170 - - [02/Jul/2014:15:07:36 -0500] "CLUSTER-BROADCAST" 500 553
10.108.30.170 - - [02/Jul/2014:15:07:37 -0500] "CLUSTER-BROADCAST" 500 553
10.108.30.170 - - [02/Jul/2014:15:07:37 -0500] "CLUSTER-BROADCAST" 500 553