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From Yang <teddyyyy...@gmail.com>
Subject guarantee of write-read order?
Date Tue, 18 Sep 2012 19:47:05 GMT
I remember that the memtable uses ConcurrentSkipListMap underneath, and
multiple writes/reads can proceed at the same time.

in my Lock implementation on cassandra, I seem to run into cases where 2
clients A and B write into the same row, different columns, on a 1-node
cluster
but the resulting read results do not seem to make sense:

A writes into Column_a and returns (with QUORUM)
B writes into Column_b and returns (with QUORUM)
A reads entire row , with QUORUM and returns
B reads entire row, with QUORUM and returns


the problem is that the 3rd line does see the write results of first 2
lines;
but the fourth line does not see both write results.


Thanks
Yang

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