Hi, As you are writing as CL.ONE and cqlsh by default reads at CL.ONE, there is a probability that you are reading stale data i.e. the node you have contacted for the read may not have the most recent data. If you have a higher consistency requirement, you should look at increasing your consistency level, for a more detailed look at this see: http://www.datastax.com/documentation/cassandra/2.0/cassandra/dml/dml_config_consistency_c.html
If you want to continue using CL.ONE, you could look at increasing the read_repair_chance for better consistency. http://www.datastax.com/documentation/cassandra/2.0/cassandra/reference/referenceTableAttributes.html Just to verify that this is in fact a consistency issue could you run a nodetool repair on that table and run the same queries again? Mark Regards, Mark On 20 August 2014 00:14, Check Peck <comptechge...@gmail.com> wrote: > We have cassandra cluster in three different datacenters (DC1, DC2 and > DC3) and we have 10 machines in each datacenter. We have few tables in > cassandra in which we have less than 100 records. > > What we are seeing - some tables are out of sync between machines in DC3 > as compared to DC1 or DC2 when we do select count(*) on it. > > As an example we did select count(*) while connecting to one cassandra > machine in dc3 datacenter as compared to one cassandra machine in dc1 > datacenter and the results were different. > > root@machineA:/home/david/apache-cassandra/bin# python cqlsh > dc3114.dc3.host.com > Connected to TestCluster at dc3114.dc3.host.com:9160. > [cqlsh 2.3.0 | Cassandra 1.2.9 | CQL spec 3.0.0 | Thrift protocol > 19.36.0] > Use HELP for help. > cqlsh> use testingkeyspace ; > cqlsh:testingkeyspace> select count(*) from test_metadata ; > > count > ------- > 12 > > cqlsh:testingkeyspace> exit > root@machineA:/home/david/apache-cassandra/bin# python cqlsh > dc18b0c.dc1.host.com > Connected to TestCluster at dc18b0c.dc1.host.com:9160. > [cqlsh 2.3.0 | Cassandra 1.2.9 | CQL spec 3.0.0 | Thrift protocol > 19.36.0] > Use HELP for help. > cqlsh> use testingkeyspace ; > cqlsh:testingkeyspace> select count(*) from test_metadata ; > > count > ------- > 16 > > What could be the reason for this sync issue? Can anyone shed some light > on this? > > Since our java driver code and datastax c++ driver code are using these > tables with CONSISTENCY LEVEL ONE. >
