hadoop namenode #23

Supports: xenial

Description

Hadoop is a software platform that lets one easily write and run applications that process vast amounts of data. This charm provides the HDFS master node (NameNode).


Overview

The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using a simple programming model.

This charm deploys the NameNode component of the Apache Bigtop platform to provide HDFS master resources.

Deploying

A working Juju installation is assumed to be present. If Juju is not yet set up, please follow the getting-started instructions prior to deploying this charm.

This charm is intended to be deployed via one of the apache bigtop bundles. For example:

juju deploy hadoop-processing

Note: The above assumes Juju 2.0 or greater. If using an earlier version of Juju, use juju-quickstart with the following syntax: juju quickstart hadoop-processing.

This will deploy an Apache Bigtop cluster with this charm acting as the NameNode. More information about this deployment can be found in the bundle readme.

Network-Restricted Environments

Charms can be deployed in environments with limited network access. To deploy in this environment, configure a Juju model with appropriate proxy and/or mirror options. See Configuring Models for more information.

Verifying

Status

Apache Bigtop charms provide extended status reporting to indicate when they are ready:

juju status

This is particularly useful when combined with watch to track the on-going progress of the deployment:

watch -n 2 juju status

The message column will provide information about a given unit's state. This charm is ready for use once the status message indicates that it is ready with datanodes.

Smoke Test

This charm provides a smoke-test action that can be used to verify the application is functioning as expected. Run the action as follows:

juju run-action namenode/0 smoke-test

Note: The above assumes Juju 2.0 or greater. If using an earlier version of Juju, the syntax is juju action do namenode/0 smoke-test.

Watch the progress of the smoke test actions with:

watch -n 2 juju show-action-status

Note: The above assumes Juju 2.0 or greater. If using an earlier version of Juju, the syntax is juju action status.

Eventually, the action should settle to status: completed. If it reports status: failed, the application is not working as expected. Get more information about a specific smoke test with:

juju show-action-output <action-id>

Note: The above assumes Juju 2.0 or greater. If using an earlier version of Juju, the syntax is juju action fetch <action-id>.

Utilities

This charm includes Hadoop command line and web utilities that can be used to verify information about the cluster.

Show the dfsadmin report on the command line with the following:

juju run --application namenode "su hdfs -c 'hdfs dfsadmin -report'"

To access the HDFS web console, find the PUBLIC-ADDRESS of the namenode application and expose it:

juju status namenode
juju expose namenode

The web interface will be available at the following URL:

    http://NAMENODE_PUBLIC_IP:50070

Contact Information

Resources