| From: | Simon Riggs <simon(at)2ndQuadrant(dot)com> |
|---|---|
| To: | Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> |
| Cc: | Dimitri Fontaine <dfontaine(at)hi-media(dot)com>, Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, David Fetter <david(at)fetter(dot)org>, Bruce Momjian <bruce(at)momjian(dot)us>, fazool mein <fazoolmein(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Synchronous replication - patch status inquiry |
| Date: | 2010-09-06 14:14:08 |
| Message-ID: | 1283782448.1834.9208.camel@ebony |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Mon, 2010-09-06 at 16:14 +0300, Heikki Linnakangas wrote:
> >
> > The standby is sending a stream of messages to the master with current
> > LSN positions at the time the message is sent. Given a synchronous
> > transaction, the master would wait until the feedback stream reports
> > that the current transaction is in the past compared to the streamed
> > last known synced one (or the same).
>
> That doesn't really answer the question: *when* does standby send back
> the acknowledgment?
I think you should explain when you think this happens in your proposal.
Are you saying that you think the standby should send back one message
for every transaction? That you do not think we should buffer the return
messages?
You seem to be proposing a design for responsiveness to a single
transaction, not for overall throughput. That's certainly a design
choice, but it wouldn't be my recommendation that we did that.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Training and Services
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2010-09-06 14:18:04 | Re: Interruptible sleeps (was Re: CommitFest 2009-07: Yay, Kevin! Thanks, reviewers!) |
| Previous Message | Greg Stark | 2010-09-06 14:07:59 | Re: Streaming a base backup from master |