I agree with Tom.. somehow I think increasing NUM_CLOG_BUFFERS is just
avoiding the symptom to a later value.. I promise to look more into it
before making any recommendations to increase NUM_CLOG_BUFFERs.
Because though "iGen" showed improvements in that area by increasing
num_clog_buffers , EAStress had shown no improvements.. Plus the reason
I think this is not the problem in 8.3beta1 since the Lock Output
clearly does not show CLOGControlFile as to be the issue which I had
seen in earlier case. So I dont think that increasing NUM_CLOG_BUFFERS
will change thing here.
Now I dont understand the code pretty well yet I see three hotspots and
not sure if they are related to each other
* ProcArrayLock waits - causing Waits as reported by
83_lockwait.d script
* SimpleLRUReadPage - causing read IOs as reported by
iostat/rsnoop.d
* GetSnapshotData - causing CPU utilization as reported by hotuser
But I will shut up and do more testing.
Regards,
Jignesh
Tom Lane wrote:
> Josh Berkus <josh@agliodbs.com> writes:
>
>> Actually, 32 made a significant difference as I recall ... do you still have
>> the figures for that, Jignesh?
>>
>
> I'd want to see a new set of test runs backing up any call for a change
> in NUM_CLOG_BUFFERS --- we've changed enough stuff around this area that
> benchmarks using code from a few months back shouldn't carry a lot of
> weight.
>
> regards, tom lane
>
