upgrades and old clients

[Ian Holsman <li...@holsman.net>]

Hi.

As we prepare to do a upgrade on our cluster this weekend, I had to stop 
and think what a PITA it is to go around and upgrade all my clients at 
the same time, especially if we have to roll it back again.

So I was wondering how hard it would be to make the RPC mechanism that 
the clients communicate on able to talk >2< versions of the protocol. 
'N' and 'N-1' so that we could upgrade the cluster, and slowly upgrade 
the clients, possibly even on a secondary port.

or am I missing something in the manual that allows this to happen already?

regards
Ian

Re: upgrades and old clients

[Sharad Agarwal <sh...@yahoo-inc.com>]

> So I was wondering how hard it would be to make the RPC mechanism that 
> the clients communicate on able to talk >2< versions of the protocol. 
> 'N' and 'N-1' so that we could upgrade the cluster, and slowly upgrade 
> the clients, possibly even on a secondary port.
>
you might want to look at the mail thread sent to 
core-dev@hadoop.apache.org with subject ""Hadoop 1.0 Compatibility 
Discussion"

Also, this might help:
http://wiki.apache.org/hadoop/Release1.0Requirements