Consistency level in cassandra issue

Question

Environment :

5 machines Cassandra 2.1.15 cluster. RF = 3, CL = QUORUM

1 machine goes down for more than 3 hours, without the possibility to bring it back

Decide to do noderemove and replace it :

The problem i saw is this :

Did heavy load over the node :

cassandra-stress write n=50000000 cl=QUORUM -rate threads=1000 -node 192.168.0.171,192.168.0.177,192.168.0.178,192.168.0.179,192.168.0.220

At one time gave me the error :

com.datastax.driver.core.exceptions.WriteTimeoutException: Cassandra timeout during write query at consistency QUORUM (3 replica were required but only 2 acknowledged the write)

According to my knowledge QUORUM = RF/2+1 rounded down => 2 replicas should be acquired.

Is this some kind of a bug!? Does it have some kind of negative impact?

Answer 1

Are you certain that cassandra-stress is using your keyspace? If you have not configured it to do so, it must be using default keyspace with replications as many as number of nodes. Try using -schema switch for cassandra-stress.

https://docs.datastax.com/en/cassandra/2.1/cassandra/tools/toolsCStress_t.html