Cassandra cluster monitoring

Question

How to collect data from all nodes within cluster from single node in cassandra. Does jmx provide aggregated values for all nodes which are present on same cluster on single node?

Answer 1

Yes. For Cassandra cluster you will be able to do so.As per my knowledge there are two well know ways for monitoring and getting cluster status.

1. nodetool utility : The nodetool utility is a command-line interface for monitoring Cassandra and performing routine database operations. Included in the Cassandra distribution, nodetool and is typically run directly from an operational Cassandra node.
2. Datastax Ops-center : OpsCenter provides a graphical representation of performance trends in a summary view that is hard to obtain with other monitoring tools. The GUI provides views for different time periods as well as the capability to drill down on single data points. Both real-time and historical performance data for a Cassandra or DataStax Enterprise cluster are available in OpsCenter. OpsCenter metrics are captured and stored within Cassandra.

I think the the first way (nodetool utility) will be more useful to meet your requirements.

You will get more information at Cassandra cluster monitoring and nodetool options.

Answer 2

JMX provides information from a single node. To have information about entire cluster we collect data from all nodes into Zabbix. Zabbix allows to create graphs and screens that show jmx values from all nodes in one place. Eg we can see all Read Pending Tasks for all nodes in single graph.

I think, to have separate information for each node in one place it's better solution to diagnose possible issues than to have common aggregate information.

Regarding metrics, I can recommend Guide to Cassandra Thread Pools that provides a description of the different cassandra metrics and how to monitor them.