Jobs not automatically started. High waits on enq: JS - queue lock

(Doc ID 1928894.1)

Last updated on DECEMBER 06, 2016

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.3 and later
Information in this document applies to any platform.

Symptoms

Scheduler Jobs not starting at their schedule time.

Only if reset the Job_Queue_processes parameter to 0 and then with a value it would work for some time and start to hang again.

The AWR is showing high waits on enq: JS - queue lock as below:

Top 5 Timed Foreground Events

Event                                Waits Time(s) Avg wait (ms) % DB time Wait Class
enq: JS - queue lock             60   3,565             59419        41.12 Other

 
 The Hang Analysis show the CJQ0 process wait on:

-------------------------------------------------------------------------------
Chain 1:
-------------------------------------------------------------------------------
   Oracle session identified by:
   {
               instance: 5 (cdp1p.cdp1p5)
                  os id: 7584
             process id: 52, oracle@wlm1l093 (CJQ0)

 

 

short stack: ksedsts()+461<-ksdxfstk()+32<-ksdxcb()+1876<-sspuser()+112<-__sighandler()<-semtimedop()+10<-skgpwwait()+160<-ksliwat()+1865<-kslwaitctx()+163<-ksqcmi()+6145<-ksqcnv()+566<-ksqcov()+41<-jsksCleanupQMemory()+485
<-jscrs_select0()+1520<-jscrs_select()+614<-rpiswu2()+1618<-kkjcjexe()+721<-kkjssrh()+561<-ksbcti()+513<-ksbabs()+1735<-ksbrdp()+971<-opirip()+623
<-opidrv()+603<-sou2o()+103<-opimai_real()+266<-ssthrdmain()+252<-main()+201<-__libc_start_main()+244<-_start()+36

Cause

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