[rabbitmq-discuss] Should I upgrade all clients if I upgrade the server to 2.2.0

[Matthew Sackman]

Hi,

On Tue, Nov 30, 2010 at 03:11:19PM +0100, Dimitri del Marmol wrote:
> I have a rabbitmq server (2.1.0) currently running in production and I
> am planning an upgrade to 2.2.0. All the clients currently use the
> 2.1.1 java client.

It is not necessary to upgrade the clients. The on-the-wire protocol has
not changed.

> Specifically:
> - is it OK to run a client with a version older than the server (eg.
> client 2.1.1 with server 2.2.0)?

Yes.

> - what about the other way around (eg. client 2.2.0 with server 2.1.1)?

Yes.

> Since 2.2.0 comes with automatic server upgrades in non clustered mode
> this is something I need to get my head around since, if I understand
> correctly, the server will upgrade automatically whereas I'm still
> responsible on upgrading the client apps.

The change is that in the past, during upgrades of the server, messages
stored in the server would simply be moved to one side if the on-disk
schema changed. That is no longer the case - we have a framework in
place that can modify the on-disk data to update it as necessary to the
format required by newer versions.

Matthew