Re: WAL archive is lost

On Fri, Nov 22, 2019 at 05:31:55AM +0000, matsumura.ryo@fujitsu.com wrote:
>Hi all
>
>I find a situation that WAL archive file is lost but any WAL segment file is not lost.
>It causes for archive recovery to fail. Is this behavior a bug?
>
>example:
>
>  WAL segment files
>  000000010000000000000001
>  000000010000000000000002
>  000000010000000000000003
>
>  Archive files
>  000000010000000000000001
>  000000010000000000000003
>
>  Archive file 000000010000000000000002 is lost but WAL segment files
>  is continuous. Recovery with archive (i.e. PITR) stops at the end of
>  000000010000000000000001.
>
>How to reproduce:
>- Set up replication (primary and standby).
>- Set [archive_mode = always] in standby.
>- WAL receiver exits (i.e. because primary goes down)
>  after receiver inserts the last record in some WAL segment file
>  before receiver notifies the segement file to archiver(create .ready file).
>
>Even if WAL receiver restarts, the WAL segment file is not notified to
>archiver.
>

That does indeed seem like a bug. We should certainly archive all WAL
segments, irrespectedly of primary shutdowns/restarts/whatever. I guess
we should make sure the archiver is properly notified befor ethe exit.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
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