Is KeyCache disabled from DSE 6.0 and 6.7?

Question

When I run nodetool info I am getting this for Key Cache

Key Cache : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 14400 save period in seconds

I enabled it in the table definition from cqlsh

caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}

I don't see any parameter in cassandra.yaml for Key Cache

Not sure why KeyCache is not being used

Answer 1

The new format of the SSTables that was introduced in the DSE 6.0 made the key cache obsolete, so it won't be used if all your SSTables were already converted to new file format. The key cache itself is left for compatibility with previous file format, and used, for example, if you migrate data from DSE 5.1, and didn't upgrade your SSTables yet.