On Thu, Nov 21, 2013 at 8:59 PM, Dilip kumar <dilip.kumar@huawei.com> wrote:
> On 20 November 2013 22:12, Sawada Masahiko Wrote
>
>> >
>> > 1. Patch applies cleanly to master HEAD.
>> > 2. No Compilation Warning.
>> > 3. It works as per the patch expectation.
>> >
>> > Some Suggestion:
>> > 1. Add new WAL level ("all") in comment in postgresql.conf
>> > wal_level = hot_standby # minimal, archive,
>> or hot_standby
>>
>> Thank you for reviewing the patch.
>> Yes, I will do that. And I'm going to implement documentation patch.
>
> OK, once I get it, I will review the same.
>
>
>> >
>> > Performance Test Result:
>> > Run with pgbench for 300 seconds
>> >
>> > WAL level : hot_standby
>> > WAL Size : 111BF8A8
>> > TPS : 125
>> >
>> > WAL level : all
>> > WAL Size : 11DB5AF8
>> > TPS : 122
>> >
>> > * TPS is almost constant but WAL size is increased around 11M.
>> >
>> > This is the first level of observation, I will continue to test few
>> more scenarios including performance test on standby.
>>
>> Thank you for performance testing.
>> According of test result, TPS of 'all' lower than 'hot_standby',but
>> WAL size is increased.
>> I think that it should be separate parameter.
>> And TPS on master side is is almost constant. so this patch might have
>> several benefit for performance improvement on standby side if the
>> result of performance test on standby side is improved.
>
> [Performance test on standby:]
>
> I have executed pgbench on master with WAL LEVEL "hot_stanby" and "all" option, and after that run pgbench on standby
with"select-only" option.
>
> WAL LEVEL (on master) : hot_standby
> Select TPS (on standby) : 4098
>
> WAL LEVEL (on master) : all
> Select TPS (on standby) : 4115
>
Thank you for testing!
It seems to have a little benefit for performance improvement on standby side.
It need to more test to write such thing into the documentation patch.
And I'm going to implement the patch as separated parameter now.
I think that this parameter should allow to use something together
with 'archive' and 'hot_standby'.
IWO not allow with 'minimal'.
Thought?
Regards,
-------
Sawada Masahiko
