Re: Architecture of walreceiver (Streaming Replication)

Hi,

On Fri, Nov 20, 2009 at 5:54 AM, Heikki Linnakangas
<heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> Thanks, I started to look at this again now.

Thanks a lot!

> I found the global LogstreamResult variable very confusing. It meant
> different things in different processes. So I replaced it with static
> globals in walsender.c and walreceiver.c, and renamed the fields to
> match the purpose better. I removed some variables from shared memory
> that are not necessary, at least not before we have synchronous mode:
> Walsender only needs to publish how far it has sent, and walreceiver
> only needs to tell startup process how far it has fsync'd.

OK.

> I changed walreceiver so that it only lets the startup process to apply
> WAL that it has fsync'd to disk, per recent discussion on hackers. Maybe
> we want to support more esoteric modes in the future, but that's the
> least surprising and most useful one.

OK. We'll need to go forward in stages.

> Plus some other minor simplifications. My changes are in my git repo at
> git://git.postgresql.org/git/users/heikki/postgres.git, branch
> "replication".

I fixed one bug. I also look through the code over and over again.

git://git.postgresql.org/git/users/fujii/postgres.git
branch: replication

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center