View Ganglia Metrics

Ganglia provides a web-based UI where you can view the metrics it collects. To do so, you'll use SSH to create a secure connection to the master node. Tunnel into the master node on port 8157 to create a secure connection. Then view the metrics from a web browser that uses a proxy tool, such as the FoxyProxy plug-in for Firefox, to create a proxy for domains of the type *ec2*.amazonaws.com*. This process is described in How to Install Foxy Proxy.

With the proxy set and the ssh connection open, you can view the Ganglia metrics by opening a browser window with http://master-public-dns-name/ganglia/.

In this URL master-public-dns-name is the public DSN name of the master node. It is formatted like the following: ec2-###-###-###-###.compute-#.amazonaws.com.

You can find the public DNS address of the master node from the command line, by calling:

elastic-mapreduce --list --all

You can also locate the public DNS of the master node in the Amazon EMR console. To do so, double-click the job flow. The DNS address is listed in the Master Public DNS Name details pane.