Re: Replication server timeout patch - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: Replication server timeout patch
Date
Msg-id 1297977683.2226.2321.camel@ebony
Whole thread Raw
In response to Re: Replication server timeout patch  (Fujii Masao <masao.fujii@gmail.com>)
Responses Re: Replication server timeout patch  (Robert Haas <robertmhaas@gmail.com>)
Re: Replication server timeout patch  (Josh Berkus <josh@agliodbs.com>)
List pgsql-hackers
On Wed, 2011-02-16 at 11:34 +0900, Fujii Masao wrote:
> On Tue, Feb 15, 2011 at 7:13 AM, Daniel Farina <daniel@heroku.com> wrote:
> > On Mon, Feb 14, 2011 at 12:48 AM, Fujii Masao <masao.fujii@gmail.com> wrote:
> >> On Sat, Feb 12, 2011 at 8:58 AM, Daniel Farina <daniel@heroku.com> wrote:
> >>> Context diff equivalent attached.
> >>
> >> Thanks for the patch!
> >>
> >> As I said before, the timeout which this patch provides doesn't work well
> >> when the walsender gets blocked in sending WAL. At first, we would
> >> need to implement a non-blocking write function as an infrastructure
> >> of the replication timeout, I think.
> >> http://archives.postgresql.org/message-id/AANLkTi%3DPu2ne%3DVO-%2BCLMXLQh9y85qumLCbBP15CjnyUS%40mail.gmail.com
> >
> > Interesting point...if that's accepted as required-for-commit, what
> > are the perceptions of the odds that, presuming I can write the code
> > quickly enough, that there's enough infrastructure/ports already in
> > postgres to allow for a non-blocking write on all our supported
> > platforms?
> 
> I'm not sure if there's already enough infrastructure for a non-blocking
> write. But the patch which I submitted before might help to implement that.
> http://archives.postgresql.org/message-id/AANLkTinSvcdAYryNfZqd0wepyh1Pf7YX6Q0KxhZjas6a%40mail.gmail.com

So, in summary, the position is that we have a timeout, but that timeout
doesn't work in all cases. But it does work in some, so that seems
enough for me to say "let's commit". Not committing gives us nothing at
all, which is as much use as a chocolate teapot.

I will be looking to commit this tomorrow morning, unless I hear some
clear No comments, with reasons.

-- Simon Riggs           http://www.2ndQuadrant.com/books/PostgreSQL Development, 24x7 Support, Training and Services



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