Re: Let PostgreSQL's On Schedule checkpoint write buffer smooth spread cycle by tuning IsCheckpointOnSchedule? - Mailing list pgsql-hackers

From Fabien COELHO
Subject Re: Let PostgreSQL's On Schedule checkpoint write buffer smooth spread cycle by tuning IsCheckpointOnSchedule?
Date
Msg-id alpine.DEB.2.10.1507030737110.9460@sto
Whole thread Raw
In response to Re: Let PostgreSQL's On Schedule checkpoint write buffer smooth spread cycle by tuning IsCheckpointOnSchedule?  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Let PostgreSQL's On Schedule checkpoint write buffer smooth spread cycle by tuning IsCheckpointOnSchedule?  (Simon Riggs <simon@2ndQuadrant.com>)
Re: Let PostgreSQL's On Schedule checkpoint write buffer smooth spread cycle by tuning IsCheckpointOnSchedule?  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
Hello Simon,

> We could do better, but that is not a reason not to commit this, as is.
> Commit, please.

My 0,02€: Please do not commit without further testing...

I've submitted a patch to improve checkpoint write scheduling, including 
X00 hours of performance test on various cases. This patch changes 
significantly the load distribution over the whole checkpoint, and AFAICS 
has been tested on rather small cases.

I'm not sure that the power 1.5 is the right one for all cases. For a big 
checkpoint over 30 minutes, it may have, or not, very large and possibly 
unwanted effects. Maybe the 1.5 factor should really be a guc. Well, what 
I really think is that it needs performance measures.

In conclusion, and very egoistically, I would prefer if this patch could 
wait for the checkpoint scheduling patch to be considered, as it would 
basically invalidate the X00 hours of performance tests I ran:-)

-- 
Fabien.

pgsql-hackers by date:

Previous
From: Fujii Masao
Date:
Subject: Re: WAL logging problem in 9.4.3?
Next
From: Marco Atzeri
Date:
Subject: PostgreSQL 9.5 Alpha 1 build fail with perl 5.22