Thread: Switchover : WAL archiving and shutdown...

Hi,

I'm setting up switchover (to another server) with WAL/PITR.

But, I'm wondering what could be the behaviour of Postgresql if you
shutdown the
service while a new WAL archive is just ready to be copied, or if the
transfer is in
progress...
Will the tranfer be canceled (until the next start), or will Postgresql
wait for the end
of the transfer before exiting ?

In other words, when I want to switchover, is it sufficient to stop
postgresql,
and rsync the last partial WAL (the last modified one), or do I have to
check if
every WAL file is in sync before starting the other server ??


Thank you in advance,
Philippe Ferreira

* Philippe Ferreira (phil.f@worldonline.fr) wrote:
> But, I'm wondering what could be the behaviour of Postgresql if you
> shutdown the
> service while a new WAL archive is just ready to be copied, or if the
> transfer is in
> progress...
> Will the tranfer be canceled (until the next start), or will Postgresql
> wait for the end
> of the transfer before exiting ?

I'd expect the transfer to continue because it's a seperate spawned
program...  I don't think it'd get a signal or be killed when the parent
shuts down but I'm not entirely sure.

> In other words, when I want to switchover, is it sufficient to stop
> postgresql,
> and rsync the last partial WAL (the last modified one), or do I have to
> check if
> every WAL file is in sync before starting the other server ??

I think you need to rsync across all of the WALs which aren't yet
archived.  That could be more than 1...  That's my understanding anyway.

    Thanks,

        Stephen