131666 - no subject - Sometimes our (Task By Process) portal r

Sometimes our (Task By Process) portal reports fail. It's not always the same process model we're reporting on, and sometimes they work and other times they do not. Each time we get a failure we receive the same error in the application server log:

2014-12-09 17:33:44,140 [ajp-/0.0.0.0:8009-5] ERROR com.appiancorp.process.analytics2.service.ProcessAnalyticsServiceFacade - com.appiancorp.kougar.driver.exceptions.Signal: index

and in the engine log we see something like...

2014-12-09 17:06:24 [PA00011] {pa131.kdb 29667} (Default) ERROR .a.p.ANLYZE.i "pricroge" "2" "id:51269" "index: exception (Report named 'CMDSFBM_processDashboard' (report document id 51269), maximum report time 2000ms) affected 0 rows"

Can anyone help us understand what might be happening?...

OriginalPostID-131666