Interesting. .. wouldn't the producer sequence grow without bounds, in the
first case, even with the simpler non-ha of key assumption, to provide a
strict exactly once semantics?

In other words, wouldn't you need to store the entire set of keys that the
broker has ever seen to ensure that a potential replayed message doesn't
make it into the commit; given multiple producers?

In mps (, I use a rotating double bloom filter
to provide a "nearly exactly once" semantics to prevent an without-bound
growth of such a sequence.

On Aug 7, 2013 4:26 PM, "Jay Kreps" <[EMAIL PROTECTED]> wrote:
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