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

From Simon Riggs
Subject Re: Synchronization levels in SR
Date
Msg-id 1274806768.6203.2237.camel@ebony
Whole thread Raw
In response to Re: Synchronization levels in SR  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On Tue, 2010-05-25 at 12:40 -0400, Robert Haas wrote:
> On Tue, May 25, 2010 at 12:28 PM, Simon Riggs <simon@2ndquadrant.com> wrote:
> > Synchronous replication implies that a commit should wait. This wait is
> > experienced by the transaction, not by other parts of the system. If we
> > define robustness at the standby level then robustness depends upon
> > unseen administrators, as well as the current up/down state of standbys.
> > This is action-at-a-distance in its worst form.
> 
> Maybe, but I can't help thinking people are going to want some form of
> this.  
> The case where someone wants to do sync rep to the machine in
> the next rack over and async rep to a server at a remote site seems
> too important to ignore.

The use case of "machine in the next rack over and async rep to a server
at a remote site" *is* important, but you give no explanation as to why
that implies "per-standby" is the solution to it.

If you read the rest of my email, you'll see that I have explained the
problems "per-standby" settings would cause.

Please don't be so quick to claim it is me ignoring anything.

-- Simon Riggs           www.2ndQuadrant.com



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