Re: gc buffer busy acquire madness
- From: Mark Bobak <Mark.Bobak@xxxxxxxxxxxx>
- To: "nadeem.m.khan@xxxxxxxxx" <nadeem.m.khan@xxxxxxxxx>, "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 9 Dec 2013 18:21:59 +0000
Yes......
Some thoughts/questions that might get you pointed in the right direction.
'gc buffer busy' usually means you're shipping excessive traffic over the
interconnect.
Some questions:
Are you (at least attempting to) isolate/partition your workload, so that
specific work runs on a specific RAC node?
Are the CPUs really busy? Is there a CPU bottleneck?
How large is the SGA? Are you using hugepages?
-Mark
From: "Nadeem M. Khan" <nadeem.m.khan@xxxxxxxxx<mailto:nadeem.m.khan@xxxxxxxxx>>
Reply-To: "nadeem.m.khan@xxxxxxxxx<mailto:nadeem.m.khan@xxxxxxxxx>"
<nadeem.m.khan@xxxxxxxxx<mailto:nadeem.m.khan@xxxxxxxxx>>
Date: Monday, December 9, 2013 at 12:57 PM
To: "oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>"
<oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>>
Subject: gc buffer busy acquire madness
Oracle 11.1.0.7 RAC on Linux with two instances prod1 and prod2
When one instance is open, the second instance takes 40 minutes to open from
the mount stage.
When both instances are open, queries take a long time to complete on prod1
When only one instance is open, queries run normally.
My top 5 waits are:
DAY EVENT_NAME
TOTAL_WAIT
--------- ----------------------------------------------------------------
----------
09-DEC-13 gc buffer busy acquire
265912
09-DEC-13 gc cr multi block request
106042
09-DEC-13 read by other session
54826
09-DEC-13 gc cr block lost
9314
09-DEC-13 DB CPU
5584
08-DEC-13 gc cr multi block request
151110
08-DEC-13 library cache load lock
9010
08-DEC-13 DB CPU
5014
08-DEC-13 gc cr block lost
1668
08-DEC-13 control file sequential read
1110
07-DEC-13 gc cr multi block request
172730
Has anyone seen this before? Thanks in advance.
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