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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Global Cache Converts & V$SYSSTAT "Time"
remember I'm old and crusty. please explain how anything that
doesn't appear on the radar in timed events can be of concern ?
BTW, please don't get me started about how many points there are in a GCS/GES remote event that involve process context switches....
I admit I don't see any such timings on any of my (many may many 16 node RAC clusters), but I don't have RAC instances sitting on the periphery idle either...but most importantly, I may be calloused is saying so, if it isn't an event the makes the top 5% I wouldn't loose sleep...it must just be "the way it works" and after paying ~60K per CPU for RAC licensing, that must be sufficient.
From: Marquez, Chris [mailto:cmarquez_at_collegeboard.org] Sent: Thursday, October 20, 2005 7:43 PM To: Kevin Closson; oracle-l_at_freelists.org Subject: RE: Global Cache Converts & V$SYSSTAT "Time" This can not be good!? Wait Events fine, but the gc times are sick. This was a rather shot inverval between statspack.snap's (takenlater at night less busy).
Top 5 Timed Events ~~~~~~~~~~~~~~~~~~ % Total Event Waits Time (s) Ela Time -------------------------------------------- ------------ ----------- -------- CPU time 123 43.92 db file sequential read 10,004 89 31.82 db file scattered read 5,103 52 18.66 log file sync 867 6 2.08 control file sequential read 449 2 .86 ------------------------------------------------------------- Cluster Statistics for DB: Instance: Snaps: 11 -12 Global Cache Service - Workload Characteristics ----------------------------------------------- Ave global cache get time (ms): 422.0 Ave global cache convert time (ms): 2,121.0 Chris Marquez Oracle DBA -----Original Message----- From: oracle-l-bounce_at_freelists.org on behalf of Marquez, Chris Sent: Thu 10/20/2005 6:24 PM To: Kevin Closson; oracle-l_at_freelists.org Subject: RE: Global Cache Converts & V$SYSSTAT "Time"should be NULL or minimal always...but that is not always the case.
>>is this one of your top 5 wait events ?
I have not run a statspack recently and regarding sessions I have been seeing all day, "No". Very few RAC related waits today if any, but I have seen them inexplicably in the past. Node2 for us is always idle, no db sessions....so RAC waits
Also, things (load, waits, etc.) were much less in general with node 2 instance down for the past few days.
Chris Marquez Oracle DBA -----Original Message----- From: Kevin Closson [mailto:kevinc_at_polyserve.com] Sent: Thu 10/20/2005 6:17 PM To: Marquez, Chris; oracle-l_at_freelists.org Subject: RE: Global Cache Converts & V$SYSSTAT "Time" is this one of your top 5 wait events ? col "Average Time" format 999.999 SELECT V$SYSSTAT.VALUE*10 / (select value from v$sysstat where name = 'global cache gets') "Average Time" FROM V$SYSSTAT WHERE V$SYSSTAT.NAME = 'global cache get time' / Average Time ------------ 19.883
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Oct 20 2005 - 22:14:08 CDT
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