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From Илья Шипицин <chipits...@gmail.com>
Subject performance is drastically degraded after 0.7.8 --> 1.0.11 upgrade
Date Wed, 29 Aug 2012 17:18:54 GMT
in terms of our high-rate write load cassandra1.0.11 is about 3 (three!!)
times slower than cassandra-0.7.8
after some investigation carried out I noticed files with "sha1" extension
(which are missing for Cassandra-0.7.8)

in maybeWriteDigest() function I see no option fot switching sha1 digests
off.

I agree, such digests save some network IO, but they seem to be very bad in
terms of CPU and disk IO.
why to use one more digest (which have to be calculated), there's already
relatively small Bloom filter file, which can be used for saving network
traffic instead of sha1 digest.

any explanation ?

Ilya Shipitsin

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