Re: Synchronous replication - patch status inquiry

On Fri, Sep 10, 2010 at 11:52:20AM +0900, Fujii Masao wrote:
> On Fri, Sep 3, 2010 at 3:42 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> > Here is the proposed detailed design:
> >
> > standbys.conf
> > =============
> > # This is not initialized by initdb, so users need to create it under $PGDATA.
> >    * The template is located in the PREFIX/share directory.
> >
> > # This is read by postmaster at the startup as well as pg_hba.conf is.
> >    * In EXEC_BACKEND environement, each walsender must read it at the startup.
> >    * This is ignored when max_wal_senders is zero.
> >    * FATAL is emitted when standbys.conf doesn't exist even if max_wal_senders
> >      is positive.
> >
> > # SIGHUP makes only postmaser re-read the standbys.conf.
> >    * New configuration doesn't affect the existing connections to the standbys,
> >      i.e., it's used only for subsequent connections.
> >    * XXX: Should the existing connections react to new configuration? What if
> >      new standbys.conf doesn't have the standby_name of the existing
> > connection?
> >
> > # The connection from the standby is rejected if its standby_name is not listed
> >  in standbys.conf.
> >    * Multiple standbys with the same name are allowed.
> >
> > # The valid values of SYNCHRONOUS field are async, recv, fsync and replay.
> >
> > standby_name
> > ============
> > # This is new string-typed parameter in recovery.conf.
> >    * XXX: Should standby_name and standby_mode be merged?
> >
> > # Walreceiver sends this to the master when establishing the connection.
>
> The attached patch implements the above and simple synchronous replication
> feature, which doesn't include quorum commit capability. The replication
> mode (async, recv, fsync, replay) can be specified on a per-standby basis,
> in standbys.conf.
>
> The patch still uses a poll loop in the backend, walsender, startup process
> and walreceiver. If a latch feature Heikki proposed will have been committed,
> I'll replace that with a latch.

Now that the latch patch is in, when do you think you'll be able to use it
instead of the poll loop?

Cheers,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
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