[erlang-questions] upgrading from R12 to R13 in a heterogeneous fashion

[Kenneth Lundin]

The compatibility between major releases is intended just for the case
when a cluster
is upgraded in service node by node.
It will probably work well for many applications to run a
heterogeneous cluster in
steady state as well but the general recommendation is to upgrade to
the same version of Erlang
on every node as fast as possible.
This applies if you are using the Erlang distribution between the nodes.
If you have invented
your own communication between the nodes it is up to your solution if
it is important to have
the same version of Erlang on every node.

/Kenneth Erlang/OTP, Ericsson


On Wed, Feb 17, 2010 at 5:08 AM, Brian Acton <acton@REDACTED> wrote:
> Hi guys,
>
> We are currently running an 8 node cluster running R12. We are wanting to
> get all the bug fixes and performance improvements from R13 (not to mention
> better support). We've been advised in the past that we shouldn't run a
> heterogeneous cluster with a mix of R12 and R13 as it is potentially
> unstable.
>
> I'm wondering if anyone has any advice on the matter and if it is OK for us
> to run a heterogeneous environment (even if it is for a short duration (like
> 24 hours) ). I'm also wondering if there are any specific gotchas or caveats
> that we should be aware of as we go down this path.
>
> Thanks!
>
> --b
>