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HBase >> mail # dev >> Thinking about 0.98


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Re: Thinking about 0.98
On Wed, Aug 21, 2013 at 10:40 PM, lars hofhansl <[EMAIL PROTECTED]> wrote:

> Could one say that 0.98 is to 0.96 what 0.94 is to 0.92?
>  Are we planning the same compatibility guarantees - i.e. no downtime
> during an upgrade from any 0.96.x to any 0.98.x release?
Sort of.

A
 0.96 client
should be able to
talk to a 0.98 server, and a mixed 0.96 and 0.98 server environment
should be
 possible
as long as the configuration doesn't change. I
f we can introduce HBASE-6721 into 0.96 at some point, then you could set
up placement groups first, and then deploy 0.98 to one placement group,
online migrate the table(s) placed there, stay in this configuration for
days or weeks, and the rest of the cluster and all of the clients would be
fine with that.

A new feature should be implemented within a well defined space for that
purpose: as a coprocessor, plugin, or as a feature of or change to HFile
V3. It could be necessary to do the placement group trick or otherwise
complete the rolling upgrade first before turning something on (including
HFile V3).

The difference is Jon has suggested API cleanups. We could have a result
where 0.96 clients will run just fine against 0.98 servers but when you
want to upgrade HBase jars for an application then a recompilation would be
needed. I think that's reasonable until the 1.0 release.

--
Best regards,

   - Andy

Problems worthy of attack prove their worth by hitting back. - Piet Hein
(via Tom White)