Unknown Hadoop Spark host name - Aster Analytics

Problem: An Aster Database queen or vworker node cannot resolve the host name of the given Hadoop Spark name node. On the queen or vworker, this command:

ping -c 3 -w 10 hadoop_node_host_name

Returns:

ping: unknown host hadoop_node_host_name

Possible Reasons:

1. The hadoop_node_host_name is misspelled.
2. The network does not allow the Aster Database queen and vworker nodes to translate hadoop_node_host_name to an IP address.

Solution:

1. Use the correct spelling of hadoop_node_host_name.
2. Perform the network system administration actions that allow the queen and vworker to translate hadoop_node_host_name to an IP address.
   For example, you might edit the /etc/hosts file of the queen and each vworker:

   1. On the queen, at the command prompt, enter:

      vi /etc/hosts

   2. Add the IP address and host name of each Hadoop name node and data node.
   3. Save the change.
   4. Exit vi.
   5. Verify that the queen can now resolve hadoop_node_host_name:

      ping -c 3 -w 10 hadoop_node_host_name

   6. To allow the vworkers to resolve hadoop_node_host_name, enter:

      ncli node clonefile /etc/hosts