Change Details

We need availability monitoring of Cassandra that goes beyond monitoring the process. Though unlikely, it's possible for the process to be present, even though the node is unable to answer a query. If that were to happen now, we'd only see this via the errors piling up in RESTBase, or as a degradation of performance. In short, a TCP port check of 9042 would be better, a custom check that ran a simple CQL query (for example: ``select host_id from system.local limit 1``) would be better still.