Re: Sync Rep Design

On 01.01.2011 19:03, Simon Riggs wrote:
> On Sat, 2011-01-01 at 17:37 +0100, Stefan Kaltenbrunner wrote:
>> On 01/01/2011 05:28 PM, Dimitri Fontaine wrote:
>>> Stefan Kaltenbrunner<stefan@kaltenbrunner.cc>   writes:
>>>> well you keep saying that but to be honest I cannot really even see a
>>>> usecase for me - what is "only a random one of a set of servers is sync at
>>>> any time and I don't really know which one".
>>>
>>> It looks easy enough to get to know which one it is.  Surely the primary
>>> knows and could update something visible through a system view for
>>> users?  This as been asked for before and I was thinking there was a
>>> consensus on this.
>>
>> well as jeff janes already said - anything that requires the master to
>> still exist is not useful for a desaster.
>
> Nobody has suggested that the master needs to still exist after a
> disaster.

Dimitri just did, see above. I agree it's not very useful.

I don't think there's any other solution to knowing which standby is 
ahead than connect to both standbys and ask how far each is. I don't see 
a problem with that, whatever middleware handles the failover and 
STONITH etc. should be able to do that too.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com