Re: Is Synchronous Postgresql Replication Slower Than Asynchronous?

On Mon, Jan 23, 2012 at 3:13 PM, Stuart Bishop <stuart@stuartbishop.net> wrote:
> On Mon, Jan 23, 2012 at 9:37 PM, Simon Riggs <simon@2ndquadrant.com> wrote:
>> On Mon, Jan 23, 2012 at 2:30 PM, Stuart Bishop <stuart@stuartbishop.net> wrote:
>>> On Sat, Jan 21, 2012 at 3:31 AM, Jerry Richards
>>> <jerry.richards@teotech.com> wrote:
>>>> Is synchronous postgresql replication slower than asynchronous?  If so, how
>>>> much?  I am looking into database replication for a phone system, so the
>>>> response time is of concern.
>>>
>>> You might want to investigate pgpool-ii. It sits as a proxy between
>>> the client and the databases, and as queries are executed
>>> simultaneously, a synchronous replication setup should be just as fast
>>> as an unreplicated setup.
>>
>> Can you share your actual results on that?
>
> No. This is based on my assumptions from the design, not from actual
> tests. I'm currently asynchronously replicated with Slony-I and
> looking at PG 9.1 builtin replication for our simpler clusters.

Sync rep 9.1 allows you to have >2 servers involved, which is really
necessary for availability and robustness.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
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