Cassandra row cache size discrepancy

Question

In cassandra.yaml I configured the row_cache_size_in_mb: 1920

On startup the log says the cache is initialized with 1920mb. But the JMX interface says RowCacheCapacityInMB as 1024mb . Why this discrepancy?

Answer 1

I took a look at the code and this is the reason.

The max size can be only 1024MB . They use an old version of concurrentlrucache library , which limits the capacity to 1024MB.

Unfortunately , I can't use a newer version of the library because of the method signature mismatch, unless I make a custom build of cassandra

Answer 2

This was fixed in the 1.1.1 release: https://issues.apache.org/jira/browse/CASSANDRA-4150 ; you should upgrade.