Mailing-List: contact mapreduce-dev-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
Reply-To: mapreduce-dev@hadoop.apache.org
Received-SPF: neutral (nike.apache.org: local policy)
DomainKey-Signature: a=rsa-sha1; s=serpent; d=yahoo-inc.com; c=nofws; q=dns;
	h=message-id:from:to:in-reply-to:content-type:
	content-transfer-encoding:mime-version:subject:date:references:x-mailer;
	b=pMHYGyszLaBT/wOPEUF2mcFSkWtxW0zSd8iXNyTLB4RAWn/nLNc0POmfZoakofpU
Message-Id: <5C03960D-5E68-46F7-BDA9-4C833B17F6E7@yahoo-inc.com>
From: Alan Gates <gates@yahoo-inc.com>
To: mapreduce-dev@hadoop.apache.org
In-Reply-To: <m2vac79ea401004211424jf1ef3eafibe070493e169cf9a@mail.gmail.com>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0 (Apple Message framework v936)
Subject: Re: Un-deprecate the old MapReduce API?
Date: Thu, 22 Apr 2010 12:12:02 -0700
References: <m2vac79ea401004211424jf1ef3eafibe070493e169cf9a@mail.gmail.com>

Speaking for one power user (Pig) that did move to the new APIs,  
moving that interface to evolving is a little unsettling.  Is there a  
feel for how much the new API is going to change?

Alan.

On Apr 21, 2010, at 2:24 PM, Tom White wrote:

> The "old" MapReduce API in org.apache.hadoop.mapred was deprecated in
> the 0.20 release series when the "new" (Context Objects) MapReduce API
> was added in org.apache.hadoop.mapreduce. Unfortunately, the new API
> was not complete in 0.20 and most users stayed with the old API. This
> has led to the confusing situation where the old API is generally
> recommended, even though it is deprecated.
>
> To remedy this situation I suggest that we remove deprecations from
> the old API in 0.20 and trunk, and mark the new API as "Evolving" (see
> MAPREDUCE-1623 for the latter). This would mean a few things:
>
> * The next 0.20 release would have a non-deprecated old API.
> * The forthcoming 0.21 release would have a "Stable" (non-deprecated)
> old API, and a "Evolving" new API.
> * For some pre-1.0 release (perhaps 0.22), the old API could be
> deprecated again, and the new API marked as "Stable".
> * In the 1.0 release it would be possible to remove the old API.
>
> Thoughts?
>
> Tom