Re: gc buffer busy acquire madness
Date: Mon, 9 Dec 2013 18:21:59 +0000
Message-ID: <CECB73AA.3C228%Mark.Bobak_at_ProQuest.com>
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_at_gmail.com<mailto:nadeem.m.khan_at_gmail.com>> Reply-To: "nadeem.m.khan_at_gmail.com<mailto:nadeem.m.khan_at_gmail.com>" <nadeem.m.khan_at_gmail.com<mailto:nadeem.m.khan_at_gmail.com>> Date: Monday, December 9, 2013 at 12:57 PM To: "oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>" <oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>> 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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