This is the documentation for CDH 4.6.0.
Documentation for other versions is available at Cloudera Documentation.

Upgrading an HDFS HA Configuration to the Latest Release

  Important:

Previous CDH4 releases implemented HA via shared storage using NFS. As of CDH4.1, you have the option of using Quorum-based Storage instead of shared storage. Cloudera recommends Quorum-based storage. If you want to use Quorum-based Storage, see Hardware Configuration for Quorum-based Storage and Software Configuration for Quorum-based Storage. If you are already using shared storage and want to switch, see Switching from Shared Storage using NFS to Quorum-based Storage.

Upgrading from CDH4 Beta 2 or Later

To upgrade your HA configuration from CDH4 Beta 2 or later to the latest release, proceed as follows:

  1. Follow the directions for upgrading a cluster under Upgrading to the Latest Version of CDH4.
  2. Start the primary NameNode (if you have not already done so) and standby NameNode, following the instructions under HDFS High Availability Initial Deployment.

Upgrading from CDH4 Beta 2 or Later and Switching from Shared Storage using NFS to Quorum-based Storage

Step 1: Shut Down the Cluster

Follow the instructions in Step 1: Prepare the cluster for the upgrade under Upgrading to the Latest Version of CDH4.

Step 2: Unconfigure HA

  1. Disable the software configuration. You should comment out the HA properties rather than deleting them.
  2. Move the NameNode metadata directories on the standby NameNode. The location of these directories is configured via the configuration options dfs.namenode.name.dir and/or dfs.namenode.edits.dir. Move them to a backup location; after the upgrade completes, you can remove them.

Step 3: Upgrade to the latest CDH4 Release

Follow the instructions in the Upgrading to the Latest Version of CDH4, starting with Step 2: Download the CDH4 package on each of the hosts in your cluster. (You have already done the first step).

Step 4: Redeploy HA using Quorum-based Storage

  1. Follow directions under Software Configuration for Quorum-based Storage.
  2. Install and start the Quorum Journal nodes, and start the primary NameNode, the standby NameNode, and the other cluster services, following the instructions under HDFS High Availability Initial Deployment.

Upgrading from CDH4 Beta 1

Upgrading from CDH4 Beta 1 requires upgrading HDFS, and unfortunately that can't be done while HA is configured. To upgrade HDFS in an HA configuration, you must unconfigure HA, upgrade HDFS, and then reconfigure HA. Proceed as follows.

Step 1: Shut Down the Cluster

Follow the instructions in Step 1: Prepare the cluster for the upgrade under Upgrading to the Latest Version of CDH4.

Step 2: Unconfigure HA

  1. Disable the software configuration. You should comment out the HA properties rather than deleting them.
  2. Move the NameNode metadata directories on the standby NameNode. The location of these directories is configured via the configuration options dfs.namenode.name.dir and/or dfs.namenode.edits.dir. Move them to a backup location; after the upgrade completes, you can remove them.

Step 3: Upgrade to the latest CDH4 Release and Upgrade HDFS

Follow the instructions in the Upgrading to the Latest Version of CDH4, starting with Step 2: Download the CDH4 package on each of the hosts in your cluster. (You have already done the first step).

Step 4: Redeploy HA

  1. Uncomment the properties you commented out in Step 2: Unconfigure HA. If you are switching to Quorum-based storage, follow directions under Software Configuration for Quorum-based Storage.
  2. If you are switching to Quorum-based storage, install and start the Quorum Journal nodes. Start the primary NameNode and the standby NameNode, and the other cluster services. Follow the instructions under HDFS High Availability Initial Deployment.