On 13.12.2010 09:50, Fujii Masao wrote:
On Mon, Dec 13, 2010 at 4:28 PM, Heikki Linnakangas
<heikki.linnakan...@enterprisedb.com> wrote:
On 13.12.2010 08:44, Fujii Masao wrote:
pg_archivecleanup removes unnecessary WAL files from the archive, but not
from pg_xlog directory. So, after failover, those WAL files might
exist in pg_xlog and be archived again later.
A file that has already been archived successfully should not be archived
again. The server keeps track of which files it has already archived with
the .ready/.done files.
This seems to require
* archiver to save the last archived WAL file name in the shmem
* walsender to send it to walreceiver
* walreceiver to create .done file when it's arrived
* bgwriter not to remove WAL files which don't have .done file in standby
Right? One good side effect of this is that we can prevent WAL files from
being removed from the standby before the master archives them.
Oh, you said "after failover", I missed that. So the problem is that the
standby might try to re-archive files that the master already archived.
If the only consequence is that you get some extra WAL files in the
archive, until pg_archivecleanup runs again, I think we can just live
with it. But don't you have bigger problems when standby tries to
archive a file that already exists in the archive, because master
already archived it? We advise to write archive_command so that it fails
if the file exists already.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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