Does the Asynchbase API actually send the exception back as the argument of the call method? Do you have the javadoc that specifies this available?

Looking at the javadocs for stumbleupon's async (which asynchbase uses) here: http://www.stumbleupon.com/su/19ESrH/tsunanet.net/~tsuna/async/api/

When the current result of a Deferred is an instance of Exception, the next errback is invoked. As for normal callbacks, whatever the errback returns becomes the current result. If the current result is still an instance of Exception, the next errback is invoked. If the current result is no longer an Exception, the next callback is invoked.

The code that calls the callback is a little clearer (https://github.com/OpenTSDB/async/blob/v1.4.0/src/Deferred.java#L688, https://github.com/OpenTSDB/async/blob/v1.4.0/src/Deferred.java#L1257):

doCall(result instanceof Exception ? eb : cb)

where eb is the "errback" and cb is the normal callback.

Abraham Fine: Has this patch been tested?

+1. Abe told me that he tested this offline.

Commit ee4999bc23f42bc300ed87b0d46fd96418d6a185 in flume's branch refs/heads/trunk from Mike Percy
[ https://git-wip-us.apache.org/repos/asf?p=flume.git;h=ee4999b ]

FLUME-2910. AsyncHBaseSink: Failure callbacks should log the exception that caused them

(Abraham Fine via Mike Percy)

Pushed to trunk. Thanks for the patch Abe!

FAILURE: Integrated in Flume-trunk-hbase-1 #161 (See https://builds.apache.org/job/Flume-trunk-hbase-1/161/)
FLUME-2910. AsyncHBaseSink: Failure callbacks should log the exception (mpercy: http://git-wip-us.apache.org/repos/asf/flume/repo?p=flume.git&a=commit&h=ee4999bc23f42bc300ed87b0d46fd96418d6a185)

• flume-ng-sinks/flume-ng-hbase-sink/src/main/java/org/apache/flume/sink/hbase/AsyncHBaseSink.java