Re: Replication - Mailing list pgsql-hackers

From Hannu Krosing
Subject Re: Replication
Date
Msg-id 1156332007.2961.25.camel@localhost.localdomain
Whole thread Raw
In response to Re: Replication  (Markus Schiltknecht <markus@bluegap.ch>)
Responses Re: Replication
List pgsql-hackers
Ühel kenal päeval, K, 2006-08-23 kell 13:09, kirjutas Markus
Schiltknecht:
> Hannu Krosing wrote:
> > But any sync _replication_ system will have severe impact on
> > performance. My guess is that for a full sync replication, going from 1
> > server to 2 will actually lower performance andsome small gains would be
> > possible only starting from 3rd server.
> 
> Only testing will show concrete results, but for sure such a general 
> answer does not make much sense. It all depends very much on the type of 
> your load. Especially the read/write ratio is very important. 

True.

But if you have very few writes, then there seems no reason to do sync
anyway.

> Another important factor is the amount of conflicting transactions.

That too, but just the need to do *any* locking on all nodes will
significantly slow down sync replication

> > My quess is based on using standard 100Gb ethernet. It may be possible
> > to do better on some more advanced interconnects like myrinet.
> 
> 100Gb ethernet already sounds very advanced... ;-)

Yeah, I meant some mix of 100Mb and 1Gb ;)

> Regards
> 
> Markus
> 
-- 
----------------
Hannu Krosing
Database Architect
Skype Technologies OÜ
Akadeemia tee 21 F, Tallinn, 12618, Estonia

Skype me:  callto:hkrosing
Get Skype for free:  http://www.skype.com




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