Data Partitioning in Cassandra

0
votes

Two questions,

Lets say I have three cassandra nodes / environments setup, Node 1, Node 2 and Node 3.

where I specified the tokens for

Node 1 as 1 to 60, Node 2 as 61 to 120, Node 3 as 121 to 255.

1) As per the Cassandra documentation, for the partition key matching 1 to 60 it should be there in Node 1 but during replication this partition data of 1 to 60 is replicated to Node 2 and Node 3. So why do we need the partition separation in it? In this case, from which node the read happens for this partitioned data?

Next question, 2) If a node goes down, Will there be a RE-PARTITIONING between Cassandra nodes?

1
javacassandracassandra-3.0

1 Answers

3
votes

1) Since number of nodes=replication factor the tokens won't matter as much. Depending on the balancing policy in your client the tokens can matter as to which node gets the request, e.g. TokenAwarePolicy.

2) Distribution of token ranges only happen when scaling your cluster.