Re: Re: [COMMITTERS] pgsql: Make standby server continuously retry restoring the next WAL

Fujii Masao wrote:
> On Fri, Feb 12, 2010 at 10:10 PM, Heikki Linnakangas
> <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
>>> So I suggest that you have a new action that gets called after every
>>> checkpoint to clear down the archive. It will remove all files from the
>>> archive prior to %r. We can implement that as a sequence of unlink()s
>>> from within the server, or we can just call a script to do it. I prefer
>>> the latter approach. However we do it, we need something initiated by
>>> the server to maintain the archive and stop it from overflowing.
>> +1
>
> If we leave executing the remove_command to the bgwriter, the restartpoint
> might not happen unfortunately for a long time.

Are you thinking of a scenario where remove_command gets stuck, and
prevents bgwriter from performing restartpoints while it's stuck? You
have trouble if restore_command gets stuck like that as well, so I think
we can require that the remove_command returns in a reasonable period of
time, ie. in a few minutes.

> To prevent that situation, the
> archiver should execute the command, I think. Thought?

The archiver isn't running in standby, so that's not going to work. And
it's not connected to shared memory either, so it doesn't know what the
latest restartpoint is.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com