Re: Archiving control (a part of synch rep patches)

Hi,

On Wed, Dec 24, 2008 at 4:39 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> (3)
> Revert the arhive status file of the specified file from .done to .ready.
> This would try to archive the corresponding xlog file again. The archive
> status of only skipped xlog file can be reverted.
>
> We resume xlog archiving by using (2) and (3), when replication
> ends.

Umm.. reverting is very tricky, then it might become hotbeds of bugs.
So, I will reconsider the method of resuming archive.

http://archives.postgresql.org/pgsql-hackers/2008-12/msg00723.php
> That conceivably might mean we need
> to write a .ready message after a WAL file filled, which might mean we
> have problems if the replication timeout is longer than the checkpoint
> timeout, but that seems an unlikely configuration. And if anybody has a
> problem with that we just recommend they use the "always" mode.

It's also problem that "reverting" competes with xlog deletion by
checkpoint.

Perhaps we should create .ready after the xlog file fills and it's
replicated during replication. I will consider this course deeply.

Happy Holidays!

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