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From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "Release1.0Requirements" by SanjayRadia
Date Thu, 02 Oct 2008 20:04:45 GMT
Dear Wiki user,

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The following page has been changed by SanjayRadia:

  ''Doug, This is a subtle issue: Here we are talking about new client application code calling
old methods on the !FileSystem class (not the RPC methods). This is in addition to the rpc
compatibility issue. --!SanjayRadia''
  ''Sanjay, How does 'new client application code calling old methods on the !FileSystem'
differ from our current back-compatibility requirements?  --DougCutting''
+ '' Doug, currently when a new RPC method is added, we declare a change in protocol version
and old and new can no long talk via rpc. There are two issues.  One is the wire compatibility
as you noted (this is new). Second is that when we add new rpc methods, the client side library
can use the new rpc method but it must fall back on old rpc methods when talking to old servers
(this must be explicitly coded in the library -- it won't happen just by introducing wire
compatibility).  You are right in that is nothing new as far as API compatibility.  Maybe
this point is obvious to most, but Owen and I discussed it at some length and thought it was
a subtle twist that our developers will have to be aware of in 1.0.''
  Question: Does the release number really matter?  Should we just keep adding features, improving
back-compatibility, etc?  Our ["Roadmap"] currently defines what a major release means.  Does
this need updating?  -- !DougCutting

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