Re: Improvement of checkpoint IO scheduler for stable transaction responses

(2013/06/26 20:15), Heikki Linnakangas wrote:
> On 26.06.2013 11:37, KONDO Mitsumasa wrote:
>>>> On Tue, Jun 25, 2013 at 1:15 PM, Heikki Linnakangas
>>>>> Hmm, so the write patch doesn't do much, but the fsync patch makes
>>>>> the response
>>>>> times somewhat smoother. I'd suggest that we drop the write patch
>>>>> for now, and focus on the fsyncs.
>>
>> Write patch is effective in TPS!
>
> Your test results don't agree with that. You got 3465.96 TPS with the write
> patch, and 3474.62 and 3469.03 without it. The fsync+write combination got
> slightly more TPS than just the fsync patch, but only by about 1%, and then the
> response times were worse.
Please see result of DBT-2 more careful. Average latency in fsync+write was
improoved from only fsync patch. 90% tile and Maximum latency are not all of
result but only part of result in DBT-2. And Average and TPS are all of result. 
Generally, when TPS become high in benchmark, checkpointer has to write more 
pages. Therefore, 90%tile and Maximum are worse in this case, and it is general 
in other benchmark tests.

Best regards,
-- 
Mitsumasa KONDO
NTT Open Source Software Center