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Date: Sun, 15 Jan 2012 23:25:35 -0800 (PST)
From: lars hofhansl <lhofhansl@yahoo.com>
Reply-To: lars hofhansl <lhofhansl@yahoo.com>
Subject: Re: HTable.flushCommits and ordering
To: "dev@hbase.apache.org" <dev@hbase.apache.org>
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It's late... Never mind... Everything is timestamped... So order does not matter.


----- Original Message -----
From: lars hofhansl <lhofhansl@yahoo.com>
To: hbase-dev <dev@hbase.apache.org>
Cc: 
Sent: Sunday, January 15, 2012 11:01 PM
Subject: HTable.flushCommits and ordering

Here's another strange client behavior:
When autoFlush is set to false on HTable (or HTable.batch is used), this triggers a Multi action at the RegionServer.

However, the RegionServer collects all Puts and executes those after all other action (presumably to make use of
batching for Puts). If the batch contains Deletes that is not correct, since the order of Deletes w.r.t. Puts is significant.

I am adding the option to force execution in the provided order (default false), which would retain the order of Puts/Deletes/etc, but
comes with a performance penalty at the server (it is still a single roundtrip, though, which is good).
I'll attach a patch for this (as part of a bigger change) to HBASE-5203 soon. Please provide your comments.

Thanks.

-- Lars