Re: Sync Rep and shutdown Re: Sync Rep v19

On 2011-03-21 18:04, Robert Haas wrote:
> On Mon, Mar 21, 2011 at 12:29 PM, Yeb Havinga<yebhavinga@gmail.com>  wrote:
>> pgbench -i -s 50 test
>> Two runs of "pgbench -c 10 -M prepared -T 600 test" with 1 sync standby -
>> server configs etc were mailed upthread.
>>
>>> - performance as of commit e148443ddd95cd29edf4cc1de6188eb9cee029c5
>> 1158 and 1306 (avg 1232)
>>> - performance as of current git master
>> 1181 and 1280 (avg 1230,5)
>>> - performance as of current git master with
>>> sync-standbys-defined-rearrangement applied
>> 1152 and 1269 (avg 1210,5)

I ran another pgbench with this last setup, which gives it a 1240,33 
average:
tps = 1300.786386 (including connections establishing)
tps = 1300.844220 (excluding connections establishing)

IMO what these tests have shown is that there is no 20% performance 
difference between the different versions. To determine if there are 
differences, n should be a lot higher, or perhaps a single one with a 
very large duration.

> Hmm, that doesn't appear to show the 20% regression Simon claimed
> upthread.  That's good...  but I'm confused as to how you are getting
> numbers this high at all without a BBU.

For the sake of testing syncrep, I put xfs in nobarrier mode on both 
master and standby:

/dev/sdc1 on /xlog type xfs (rw,noatime,nodiratime,nobarrier)
/dev/md11 on /archive type xfs 
(rw,noatime,nodiratime,nobarrier,logdev=/dev/sdc3)
/dev/md10 on /data type xfs 
(rw,noatime,nodiratime,nobarrier,logdev=/dev/sdc2)

-- 
Yeb Havinga
http://www.mgrid.net/
Mastering Medical Data