Amazon Elastic MapReduce
Developer Guide (API Version 2009-03-31)
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Web Interfaces Hosted on the Master Node

Hadoop, Ganglia, and other applications publish user interfaces as websites hosted on the master node. For security reasons, these websites are only available on the master node's local webserver (http://localhost:port) and are not published on the Internet. There are several ways you can access these web interfaces:

  • Use SSH to connect to the master node and use the text-based browser, Lynx, to view the websites from the SSH terminal. The following example shows how to open the Hadoop JobTracker user interface using Lynx. This is the easiest and quickest way to access these web interfaces. The disadvantage is that Lynx is a text-based browser with a limited user interface that cannot display graphics.

    lynx http://localhost:9100/

    Note

    To permit SSH access to a master node, you must add your external source IP for TCP Port 22 to the ingress rules on the master node security group. For more information, see Adding a Security Group Rule in the Amazon Elastic Compute Cloud User Guide.

  • Create an SSH tunnel to the master node and manually configure your browser to use the SOCKS proxy you've just created for all URLs. This has the advantage of being relatively easy to configure (see your web browser's documentation for details). The disadvantage is you must then manually disable the proxy in your browser to resume normal web browsing. The following screenshot shows the settings you'd use to manually configure Safari to view the web interfaces over a SOCKS proxy.

  • Create an SSH tunnel to the master node and use a browser add-on, such as FoxyProxy (an add-on for the FireFox browser), to automatically filter URLs based on text patterns and use the SOCKS proxy you've created only for domains that match the form of an EC2 instance's public DNS name. This requires that you install an add-on and configure the appropriate patterns in it, but once done, automatically handles turning the proxy on and off when you switch between viewing websites hosted on the master node, and those on the Internet. For more information about how to configure FoxyProxy, see Configure FoxyProxy to View Websites Hosted on the Master Node.

The following table lists web interfaces you can view on the master node. The Hadoop interfaces are available on all clusters. Other web interfaces, such as Ganglia, are only available if additional features have been added to the cluster.

Name of Interface

URI

Hadoop MapReduce job tracker http://master-public-dns-name:9100/
Hadoop HDFS name node http://master-public-dns-name:9101/
Hadoop MapReduce task tracker http://master-public-dns-name:9103/
Ganglia Metrics Reports http://master-public-dns-name/ganglia/
HBase Interface http://master-public-dns-name:60010/master-status

For more information about the Hadoop web interfaces, see View Web Interfaces on the Cluster (Hadoop 2.x). For more information about the Ganglia web interface, see Monitor Performance with Ganglia.