Connecting to Cassandra JMX via SSH

This post is based on http://gabrielcain.com/blog/2010/11/02/using-ssh-proxying-to-connect-jconsole-to-remote-cassandra-instances/.

1. Make sure you can ssh into the Cassandra node without typing a password
2. On the server running Cassandra edit cassandra-env.sh and include the hostname of the machine in the 'java.rmi.server.hostname' property (JVM_OPTS="$JVM_OPTS -Djava.rmi.server.hostname=foo.bar.com"
3. On the client machine add the 'jc' function to your bash (or whatever) profile:
   
   

   function jc {
       # set this to the host you'll proxy through.
       proxy_host="dan@foo.bar.com"
       host=$1
   
       jmxport=8080 # as specified by JMX_PORT in cassandra-env.sh
       proxy_port=${2:-8123}
   
       if [ "x$host" = "x" ]; then
           echo "Usage: jc  [proxy port]"
           return 1
       fi 
   
       # start up a background ssh tunnel on the desired port
       ssh -N -f -D$proxy_port $proxy_host 
   
       # if the tunnel failed to come up, fail gracefully.
       if [ $? -ne 0 ]; then
           echo "Ssh tunnel failed"
           return 1
       fi
   
       ssh_pid=`ps awwwx | grep "[s]sh -N -f -D$proxy_port" | awk '{print $1}'`
       echo "ssh pid = $ssh_pid"
   
       # Fire up jconsole to your remote host
       jconsole -J-DsocksProxyHost=localhost -J-DsocksProxyPort=$proxy_port \
           service:jmx:rmi:///jndi/rmi://${host}:${jmxport}/jmxrmi
   
       # tear down the tunnel
       kill $ssh_pid
   }

4. Source the 'jc' function added to your bash profile (e.g. 'source ~/.bash_login')
5. Open jconsole using: 'jc foo.bar.com'