cassandra-metrics-collector

Note: This branch supports Cassandra >= 3.0 (tested with 3.10). For Cassandra 2.1, please use the v21 branch, for Cassandra 2.2, use the v22 branch.

Discovers running instances of Cassandra on the local machine, collects performance metrics (via JMX, using a domain socket), and writes them to Graphite/Carbon in a format compatible with the Dropwizard metrics GraphiteReporter.

This tool is capable of discovering and collecting from an arbitrary number of local Cassandra instances, and so it is required that you disambiguate instances by passing a -Dcassandra.instance-id=<name> system property to Cassandra at startup. This instance name will be used to derive the metric prefix string unique to each instance, (in the form of cassandra.<name>.).

Build

$ mvn package

Run

$ java -jar target/cassandra-metrics-collector-<version>-jar-with-dependencies.jar --help

NAME
        cmcd - cassandra-metrics-collector daemon

SYNOPSIS
        cmcd [ {-di | --discovery-interval} <INTERVAL> ]
                [ {-f | --filter-config} <YAML> ] [ {-h | --help} ]
                [ {-H | --carbon-host | --graphite-host} <HOSTNAME> ]
                [ {-i | --interval} <INTERVAL> ]
                [ {-p | --carbon-port | --graphite-port} <PORT> ]

OPTIONS
        -di <INTERVAL>, --discovery-interval <INTERVAL>
            Interval (in seconds) to perform (re)discovery (default: 300
            seconds)

        -f <YAML>, --filter-config <YAML>
            Metric filter configuration

        -h, --help
            Display help information

        -H <HOSTNAME>, --carbon-host <HOSTNAME>, --graphite-host <HOSTNAME>
            Carbon hostname (default: localhost)

        -i <INTERVAL>, --interval <INTERVAL>
            Collection interval in seconds (default: 60 seconds)

        -p <PORT>, --carbon-port <PORT>, --graphite-port <PORT>
            Carbon port number (default: 2003)

For example:

$ export CLASSPATH=/path/to/apache-cassandra.jar:/path/to/cassandra-metrics-collector-<version>-jar-with-dependencies.jar
$ java org.wikimedia.cassandra.metrics.service.Service \
        --interval 60 \
        --carbon-host carbon-1.example.com \
        --carbon-port 2003 \

Simple invocation

It is also possible to invoke a single collection cycle against a specific instance over TCP.

$ export CLASSPATH=/path/to/apache-cassandra.jar:/path/to/cassandra-metrics-collector-<version>-jar-with-dependencies.jar
$ java org.wikimedia.cassandra.metrics.Command
Usage: Command <jmx host> <jmx port> <graphite host> <graphite port> <prefix>

For example:

$ export CLASSPATH=/path/to/apache-cassandra.jar:/path/to/cassandra-metrics-collector-<version>-jar-with-dependencies.jar
$ java -cp org.wikimedia.cassandra.metrics.Command \
      db-1.example.com \
      7199 \
      carbon-1.example.com \
      2003 \
      cassandra.db-1

Testing locally

To test locally, use nc (netcat).

Open a socket and listen on port 2003:

$ nc -lk 2003

Collect Cassandra metrics and write to netcat:

$ export CLASSPATH=/path/to/apache-cassandra.jar:/path/to/cassandra-metrics-collector-<version>-jar-with-dependencies.jar
$ java org.wikimedia.cassandra.metrics.service.Service \
      --interval 15 \
      --carbon-host localhost \
      --carbon-port 2003 \