AccessShareLock and Resource Contention
I have a 9.2 server that occasionally becomes CPU bound. Disk wait is
nominal and there's no memory pressure. The workload is almost all reads
and the cache hit rate is high.
For some one minute periods, my monitoring shows around 1.5k to 2k access
share locks out of a total of 7.5 to 8k transactions. What's the best
strategy for finding out if that is creating a bottleneck?
Hit send on that one too soon. I see 6.5k access share locks out of 7.5k
transactions.
On Tue, Nov 26, 2013 at 12:41 PM, <maillists0@gmail.com> wrote:
Show quoted text
I have a 9.2 server that occasionally becomes CPU bound. Disk wait is
nominal and there's no memory pressure. The workload is almost all reads
and the cache hit rate is high.For some one minute periods, my monitoring shows around 1.5k to 2k access
share locks out of a total of 7.5 to 8k transactions. What's the best
strategy for finding out if that is creating a bottleneck?
On Tue, Nov 26, 2013 at 12:41 PM, <maillists0@gmail.com> wrote:
I have a 9.2 server that occasionally becomes CPU bound. Disk wait is
nominal and there's no memory pressure. The workload is almost all reads
and the cache hit rate is high.
Maybe you'd benefit from something like the patch proposed here:
/messages/by-id/20131115194725.GG5489@awork2.anarazel.de
perhaps you can help test the patchset.
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On Tue, Nov 26, 2013 at 9:50 AM, <maillists0@gmail.com> wrote:
Hit send on that one too soon. I see 6.5k access share locks out of 7.5k
transactions.On Tue, Nov 26, 2013 at 12:41 PM, <maillists0@gmail.com> wrote:
I have a 9.2 server that occasionally becomes CPU bound. Disk wait is
nominal and there's no memory pressure. The workload is almost all reads
and the cache hit rate is high.
Do you see higher user time, or high system time? What is the maximum
number of concurrent connections you have?
For some one minute periods, my monitoring shows around 1.5k to 2k access
share locks out of a total of 7.5 to 8k transactions. What's the best
strategy for finding out if that is creating a bottleneck?
How are you monitoring? What do those numbers mean, that you took that
many access shared locks, or you held that many simultaneously at the peak,
or that you blocked on them that many times?
Cheers,
Jeff