Re: Synchronization levels in SR - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Synchronization levels in SR
Date
Msg-id 4BFD5F1A.9090503@enterprisedb.com
Whole thread Raw
In response to Re: Synchronization levels in SR  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: Synchronization levels in SR
List pgsql-hackers
On 26/05/10 20:33, Kevin Grittner wrote:
> Heikki Linnakangas<heikki.linnakangas@enterprisedb.com>  wrote:
>
>> Although, if the master crashes at that point, and quickly
>> recovers, you could see the last transactions committed on the
>> master before they're replicated to the standby.
>
> Versus having the transaction committed on one or more slaves but
> not on the master?  Unless we have a transaction manager and do
> proper distributed transactions, how do you avoid edge conditions
> like that?

Yeah, I guess you can't. You can guarantee that a commit is always 
safely flushed first in the master, or in the standby, but without 
two-phase commit you can't guarantee atomicity. It's useful to know 
which behavior you get, though, so that you can take it into account in 
your failover procedure.

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


pgsql-hackers by date:

Previous
From: Selena Deckelmann
Date:
Subject: Re: WIP patch for serializable transactions with predicate locking
Next
From: Stephen Frost
Date:
Subject: psql \? \daS