Cassandra cannot parse ‘my_key’ as hex bytes

If you have “cannot parse ‘whatever_my_key’ as hex bytes” when you try to query Cassandra for some data, as in example below:

get ServerLog['my_key'] limit 10;
 
org.apache.cassandra.db.marshal.MarshalException: cannot parse 'my_key' as hex bytes

then you must set the client-side encoding with assume command:

assume ServerLog keys as utf8;