Currently the Cassandra store is creating CassandraKeys based on the keys .toString method, see below:
private String hashKey(Object key)

When HotRod server is used the key will be a ByteArrayKey, which has a toString that is non deterministic and outputs (3 examples with the same byte array):
ByteArrayKey{data=ByteArray{size=8, hashCode=33d626a4, array=[2, 62, 5, 74, 79, 78, 65, 83, ..]}}
ByteArrayKey{data=ByteArray{size=8, hashCode=2ada52a1, array=[2, 62, 5, 74, 79, 78, 65, 83, ..]}}
ByteArrayKey{data=ByteArray{size=8, hashCode=5576b9ea, array=[2, 62, 5, 74, 79, 78, 65, 83, ..]}}

As you can see the hashCode is differing even though the byte array is the same.

This is because ByteArrayKey.toString is using Util.printArray(byte[],true) where true means that a hashCode should be printed as well.
Unfortenaly, the hashcode is calculated with byte[].hashCode() which is not considering the data in the byte array.

There are several solutions to the problem:

• Have another mechanism to export unique ids from the key instead of toString (with a possible toString fallback)
• Fix so that ByteArrayKey.toString returns deterministic data. (Still bad solution as the keys will be very long and not make sense).
• Special handling for ByteArrayKey to calculate the key based on the bytes in the byte array.