View Web Interfaces Hosted on Amazon EMR Clusters
Hadoop and other applications you install on your Amazon EMR cluster, publish user interfaces as web sites hosted on the master node. For security reasons, these web sites are only available on the master node's local web server and are not publicly available over the Internet. Hadoop also publishes user interfaces as web sites hosted on the core and task (slave) nodes. These web sites are also only available on local web servers on the nodes.
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 and HBase are only available
if you install additional applications on your cluster. To access the following
master-public-dns-name in the URI with
the DNS name of the master node after creating an SSH tunnel. For more information about
retrieving the master public DNS name, see Retrieve the Public DNS Name of the Master
Node. For more
information about creating an SSH tunnel, see Option 2, Part 1: Set Up an SSH Tunnel to the Master
Node Using Dynamic Port Forwarding.
|Name of interface||
|Hadoop version 2.x|
|Hadoop HDFS NameNode|| http://|
|Ganglia Metrics Reports||
|Hue Web Application||
|Hadoop version 1.x|
|Hadoop MapReduce JobTracker||
|Hadoop HDFS NameNode||
|Ganglia Metrics Reports||
For more information, see the following:
You can change the configuration of the Hadoop version 2.x web interfaces by
conf/hdfs-site.xml file. You can change the
configuration of the Hadoop version 1.x web interfaces by editing the
Because there are several application-specific interfaces available on the master node that are not available on the core and task nodes, the instructions in this document are specific to the Amazon EMR master node. Accessing the web interfaces on the core and task nodes can be done in the same manner as you would access the web interfaces on the master node.
There are several ways you can access the web interfaces on the master node. The easiest and quickest method is to use SSH to connect to the master node and use the text-based browser, Lynx, to view the web sites in your SSH client. However, Lynx is a text-based browser with a limited user interface that cannot display graphics. The following example shows how to open the Hadoop ResourceManager interface using Lynx (Lynx URLs are also provided when you log into the master node using SSH).
There are two remaining options for accessing web interfaces on the master node that provide full browser functionality. Choose one of the following:
Option 1 (recommended for more technical users): Use an SSH client to connect to the master node, configure SSH tunneling with local port forwarding, and use an Internet browser to open web interfaces hosted on the master node. This method allows you to configure web interface access without using a SOCKS proxy.
Option 2 (recommended for new users): Use an SSH client to connect to the master node, configure SSH tunneling with dynamic port forwarding, and configure your Internet browser to use an add-on such as FoxyProxy or SwitchySharp to manage your SOCKS proxy settings. This method allows you to automatically filter URLs based on text patterns and to limit the proxy settings to domains that match the form of the master node's DNS name. The browser add-on 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 for Firefox and Google Chrome, see Option 2, Part 2: Configure Proxy Settings to View Websites Hosted on the Master Node.
- Option 1: Set Up an SSH Tunnel to the Master Node Using Local Port Forwarding
- Option 2, Part 1: Set Up an SSH Tunnel to the Master Node Using Dynamic Port Forwarding
- Option 2, Part 2: Configure Proxy Settings to View Websites Hosted on the Master Node
- Access the Web Interfaces on the Master Node Using the Console