One ColumnFamily places data on only 3 out of 4 nodes

Solution 1:

SimpleStrategy means Cassandra distributes the data without respect for racks, datacenters, or other geography. That's important information for understanding data distribution, but it's not enough to fully analyze your situation.

If you want to understand how rows distribute over a cluster, it's also an issue of the partitioner you use. The random partitioner hashes row keys before deciding on the cluster members that should have them. The order-preserving partitioner does not, which can create hot spots (including total non-use of a node!) on the cluster, even if your nodes have equal divisions of the ring. You can experiment with how Cassandra will distribute different keys using the following command on one of your nodes to see where Cassandra thinks different keys (actual or hypothetical) belong on which nodes:

nodetool -h localhost getendpoints <keyspace> <cf> <key>

If other column families are distributing their data properly over the cluster, I would look into the partitioner and keys you're using.