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Date: Wed, 05 Nov 2014 19:31:57 -0500
From: Josh Elser <josh.elser@gmail.com>
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To: dev@accumulo.apache.org
Subject: Re: TabletLocator API stability / alternates?
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I don't think there is any class/method that we consider to be in our 
"Public API" that does what you want.

You're also not the first one that has tried to do something using 
TabletLocator and has been bitten by it 
(https://issues.apache.org/jira/browse/ACCUMULO-2594).

At this point, I think we should look at bringing tablet locality into 
the public API for 1.7.0 or 2.0.0. Would you be interested in filing an 
issue on JIRA and helping to flesh out the functionality requirements?

Chris Bennight wrote:
> So we have some code (a custom input format for data persisted in accumulo
> with a custom indexing scheme (geospatial/n-dimensional)):
>
> https://github.com/ngageoint/geowave/blob/GEOWAVE-84-squash/geowave-accumulo/src/main/java/mil/nga/giat/geowave/accumulo/mapreduce/input/GeoWaveInputFormat.java#L355
>
> The intent behind this was to provide better locality and split information
> since we have a bit more application specific knowledge available than the
> general use case.
>
> I'm pretty sure there's no other way to get this locality information other
> than using the TableLocator class.
>
> The arguments + ordering change for TCredentials to Credentials and the
> method signature from getInstance() to getLocator() are the two things
> breaking our 1.5.1 ->  1.6.x compatibility.
> (specifically:
> https://github.com/apache/accumulo/commit/99da5641c28784c7b717cce6749673863c2ec8cf#diff-c45768534f53d5455cc05c75676fb871R49
> https://github.com/apache/accumulo/commit/446a37a9795f2df7adc841154ca05add79cf286e#diff-c45768534f53d5455cc05c75676fb871R95
> )
>
> It's pretty obvious from the diff these were intentional - so no joy there
> in accidental changes that could be fixed.
>
> Are we just to far down in the weeds, and are going to have to deal with
> supporting multiple versions/breaking changes (via refactoring, dropping
> support, or maven-munge maybe), or is this class/methods/signatures
> expected to be pretty stable now?
>
> (Or is there a better/more supported way of getting tablet locality
> information?)
>