Re: New sync commit mode remote_write - Mailing list pgsql-hackers

From Jeff Janes
Subject Re: New sync commit mode remote_write
Date
Msg-id CAMkU=1xcC64nY3T_aVCYw0M78iiFEWQVvOaSkbBnQKpHdXzFJQ@mail.gmail.com
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In response to Re: New sync commit mode remote_write  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: New sync commit mode remote_write  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On Thu, Apr 19, 2012 at 11:50 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> On 4/19/12, Jeff Janes <jeff.janes@gmail.com> wrote:
>> The work around would be for the master to refuse to automatically
>> restart after a crash, insisting on a fail-over instead (or a manual
>> forcing of recovery)?
>
> I suppose that would work, but I think Simon's idea is better: don't
> let the slave replay the WAL until either (a) it's promoted or (b) the
> master finishes the fsync.   That boils down to adding some more
> handshaking to the replication protocol, I think.

Alternative c) is that the master automatically recovers from a crash,
but doesn't replay that particular wal record because it doesn't find
it on disk, so the slave has to be instructed to throw it away.  (Or
perhaps the slave could feed the wal back to the master, so the master
could replay it?)

Cheers,

Jeff


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