Changing the system clock underneath a multi-master setup

[Michael Parker <mi...@gmail.com>]

I have two servers running CouchDB in a multi-master setup, where each
is performing a continuous pull replication on the other. I stupidly
assumed that both servers had their system time set appropriately with
ntpd, but I was wrong, and they're both off by a minute or two. Will
running ntpd on each server affect CouchDB or the replication at all?
Should I play it safe and stop replication, down CouchDB, change the
clock, and then up CouchDB and start replication again?

(Sorry if this sounds super-paranoid.)

Thanks!

- Mike

Re: Changing the system clock underneath a multi-master setup

[Dave Cottlehuber <da...@muse.net.nz>]

On 22 August 2012 20:13, Michael Parker <mi...@gmail.com> wrote:
> I have two servers running CouchDB in a multi-master setup, where each
> is performing a continuous pull replication on the other. I stupidly
> assumed that both servers had their system time set appropriately with
> ntpd, but I was wrong, and they're both off by a minute or two. Will
> running ntpd on each server affect CouchDB or the replication at all?
> Should I play it safe and stop replication, down CouchDB, change the
> clock, and then up CouchDB and start replication again?

I think you can change the clock quite safely. The erlang runtime will
likely emit
some warnings, but with a delta < 5 minutes this should not cause it
to restart[1].

With this short a time difference, I'd not get ntpd to forcefully
update, but let it
drift onto the corrected time. This will no doubt be platform dependent.

A+
Dave

[1]:http://www.erlang.org/doc/man/heart.html