Hi all!

We have a problem with cassandra 2.0. We have installed cassandra from datastax community respository. We haven't changed any java options from the default ones. De-facto Xmx is 1GB. Recently we have encountered a couple of cases when cassandra stopped responding and the log was showing some constant gc activity. My assumption is that the reason we are having this is because of low Xmx. Although we don't have much load on this server we do have a lot of column families (cql tables). If I understand correctly each column family takes some memory for service purposes. Is that so? Is there any Xmx recommendation formula that takes into account the column family count and the read/write ops?

Thanks in advance!