Session hangs on "buffer busy waits"

  • From: "Nahata, Naveen" <Naveen.Nahata@xxxxxxxxxxxxxxx>
  • To: <ORACLE-L@xxxxxxxxxxxxx>
  • Date: Wed, 16 May 2007 18:14:36 -0400

Oracle Ebusiness Suite, on Solaris 9 64-bit.

One of the workflow agent processes occassionally hangs. V$session_wait
shows state = 'WAITING', event = 'buffer busy waits' and seconds_in_wait
keep incrementing until I resolve it by flushing the buffer cache. Since
the session holds multiple locks on key application tables, almost all
the sessions hang waiting on "enqueue".

I tracked down the block to AQ$_WF_JAVA_DEFERRED_I table. 

Has anyone seen anything similar? Any ideas on how I can debug it

I've seen performance issues with the AQ tables before and am thinking
of rebuilding the queues and reorganizing the objects. Hopefully this
will alleviate the problem. 


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