I also thought that version mismatch is FB specific.
Other people will not be able to run different versions of NN and SNN.
On 4/2/2010 10:41 AM, Todd Lipcon wrote:
> On Fri, Apr 2, 2010 at 10:38 AM, Stack<[EMAIL PROTECTED]> wrote:
>> > Please on committing HDFS-1024 to the hadoop 0.20 branch.
>> > Background:
>> > HDFS-1024 fixes possible trashing of fsimage because of failed copy
>> > from 2NN and NN. Ordinarily, possible corruption of this proportion
>> > would merit commit w/o need of a vote only Dhruba correctly notes that
>> > UNLESS both NN and 2NN are upgraded, HDFS-1024 becomes an incompatible
>> > change (the NN<->2NN communication will fail always). IMO, this
>> > incompatible change can be plastered over with a release note; e.g.
>> > WARNING, you MUST update NN and 2NN when you go to 0.20.3 hadoop. If
>> > you agree with me, please vote +1 on commit.
> +1. If I recall correctly the NN and 2NN already do a very strict version
> check in branch 20, so it's not any more incompatible than any other change.
> (I think Dhruba made the version check less strict in the FB branch)