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From Robert Stupp <sn...@snazy.de>
Subject Re: Using Cassandra as cache
Date Fri, 20 Jun 2014 22:01:25 GMT

Am 20.06.2014 um 23:48 schrieb Pavel Kogan <pavel.kogan@cortica.com>:

> 1) When new keyspace with its columnfamilies is being just created (every round hour),
sometimes other modules failed to read/write data, and we lose request. Can it be that creation
of keyspace and columnfamilies is async operation or there is propagation time between nodes?


Schema needs to "settle down" (nodes actually agree on a common view) - this may take several
seconds until all nodes have that common view. Turn on DEBUG output in Java driver for example
to see these messages.
CL ONE requires the "one" node to be up and running - if that node's not running your request
will definitely fail. Maybe you want to try CL ANY or increase RF to 2.

> 2) We are reading and writing intensively, and usually I don't need the data for more
than 1-2 hours. What optimizations can I do to increase my small cluster read performance?
Cluster configuration - 3 identical nodes: i7 3GHz, SSD 120Gb, 16Gb RAM, CentOS 6.

Depending on the data, table layout, access patterns and C* version try with various key cache
and maybe row cache configurations in both table options and cassandra.yaml


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