Re: What is the most optimal config parameters to keep stable write TPS ?..

Thanks a lot, I'll try them all!

Yes, I have a good external storage box with battery backed cache enabled.
There are 64GB of RAM so I expected it'll help little bit to increase
a buffer cache, but ok, will see if with 256MB it'll be better :-)

What about "full_page_writes" ? seems it's "on" by default. Does it
makes sense to put if off?..

Rgds,
-Dimitri

On 5/11/09, Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov> wrote:
> Dimitri <dimitrik(dot)fr(at)gmail(dot)com> wrote:
>
>> PostgreSQL: 8.3.7 & 8.4
>> Server: Sun M5000 32cores
>> OS: Solaris 10
>
> Does that have a battery backed RAID controller? If so, is it
> configured for write-back? These both help a lot with smoothing
> checkpoint I/O gluts.
>
> We've minimized problems by making the background writer more
> aggressive. 8.3 and later does a better job in general, but we've
> still had to go with:
>
> bgwriter_lru_maxpages = 1000
> bgwriter_lru_multiplier = 4.0
>
>> shared_buffers = 12000MB
>
> You might want to test with that set to something much lower, to see
> what the checkpoint delays look like. We've found it best to use a
> small (256MB) setting, and leave caching to the OS; in our
> environment, it seems to do a better job of scheduling the disk I/O.
> YMMV, of course.
>
> -Kevin
>