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From Peter Schuller <>
Subject Re: Invalid Counter Shard errors?
Date Thu, 20 Sep 2012 06:22:14 GMT
The significance I think is: If it is indeed the case that the higher
value is always *in fact* correct, I think that's inconsistent with
the hypothesis that unclean shutdown is the sole cause of these
problems - as long as the client is truly submitting non-idempotent
counter increments without a read-before-write.

As a side note: If hou're using these counters for stuff like
determining amounts of money to be payed by somebody, consider the
non-idempotense of counter increments. Any write that increments a
counter, that fails by e.g. Timeout *MAY OR MAY NOT* have been applied
and cannot be safely retried. Cassandra counters are generally not
useful if *strict* correctness is desired, for this reason.

/ Peter Schuller (@scode,

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