Ensure High Availability is Enabled

To enable high availability, see HDFS High Availability for instructions. You do not need to enable automatic failover for rolling restart to work, though you can enable it if you want. Automatic failover does not affect the rolling restart operation. If you have JobTracker high availability configured, Cloudera Manager will fail over the JobTracker during the rolling restart, but this is not a requirement for performing a rolling upgrade.

Download, Distribute, and Activate Parcels

1. In the Cloudera Manager Admin Console, click the Parcels indicator in the top navigation bar ( or ) to go to the Parcels page.
2. In the parcels page, click Download for the version(s) you want to download. If the parcel you want is not shown here — for example, you want to upgrade to version of CDH that is not the most current version — you can make additional parcel repos available through the parcel settings page. If your Cloudera Manager server does not have Internet access, you can obtain the required parcel file(s) and put them into the local repository. See Creating and Using a Remote Parcel Repository for Cloudera Manager for more details.
3. When the download has completed, click Distribute for the version you downloaded.
4. When the parcel has been distributed and unpacked, the button will change to say Activate.
5. Click Activate. You are asked if you want to restart the cluster. Do not restart the cluster at this time.
6. Click Close.

Upgrade the Hive Metastore Database

Upgrade the Oozie ShareLib

1. Go to the Oozie service.
2. Select Actions > Start and click Start to confirm.
3. Select Actions > Install Oozie ShareLib and click Install Oozie ShareLib to confirm.

Upgrade Sqoop

1. Go to the Sqoop service.
2. Select Actions > Stop and click Stop to confirm.
3. Select Actions > Upgrade Sqoop and click Upgrade Sqoop to confirm.

Upgrade the Sentry Database

1. Go to the Sentry service.
2. Select Actions > Stop and click Stop to confirm.
3. Select Actions > Upgrade Sentry Database Tables and click Upgrade Sentry Database Tables to confirm.

Upgrade Spark

1. Go to the Spark service.
2. Select Actions > Stop and click Stop to confirm.
3. Select Actions > Install Spark JAR and click Install Spark JAR to confirm.
4. Select Actions > Create Spark History Log Dir and click Create Spark History Log Dir to confirm.

Restart the Cluster

1. On the Home > Status tab, click to the right of the cluster name and click Rolling Restart to proceed with a rolling restart. Rolling restart is available only if high availability is enabled. Click Restart to perform a normal restart. Services that do not support rolling restart will undergo a normal restart, and will not be available during the restart process.
2. For a rolling restart, a pop-up allows you to chose which services you want to restart, and presents caveats to be aware of for those services that can undergo a rolling restart.
     Note: If you have just upgraded your Cloudera Manager deployment to 4.6, and are now doing a rolling upgrade of your cluster, you must ensure that MapReduce is restarted before the rest of your services, or the restart may fail. This is necessary to ensure the MapReduce configuration changes are propagated.

   Further, if you are upgrading from CDH 4.1 with Impala to CDH 4.2 or 4.3, you must restart MapReduce before Impala restarts (by default Impala is restarted before MapReduce).

   The workaround is to perform a restart of MapReduce alone as the first step, then perform a cluster restart of the remaining services.

3. Click Confirm to start the rolling restart.

Remove CDH 4 Packages

If your previous installation of CDH was done using packages, remove those packages on all hosts on which you installed the parcels and refresh the symlinks so that clients will run the new software versions. Skip this step if your previous installation was using parcels.

1. If Hue is configured to use SQLite as its database:
   1. Stop the Hue service.
   2. Back up the desktop.db to a temporary location before deleting the old Hue Common package. The location of the database can be found in the Hue service Configuration tab under Service > Database > Hue's Database Directory.
     Important: Removing the Hue Common package will remove your Hue database; if you do not back it up you may lose all your Hue user account information.
2. Uninstall the CDH packages on each host:
   • Not including Impala and Search

     Operating System	Command
     RHEL	$ sudo yum remove hadoop hue-common bigtop-jsvc bigtop-tomcat
     SLES	$ sudo zypper remove hadoop hue-common bigtop-jsvc bigtop-tomcat
     Ubuntu or Debian	$ sudo apt-get purge hadoop hue-common bigtop-jsvc bigtop-tomcat

   • Including Impala and Search

     Operating System	Command
     RHEL	$ sudo yum remove hadoop hue-common impala-shell solr-server 'bigtop-*'
     SLES	$ sudo zypper remove hadoop hue-common impala-shell solr-server 'bigtop-*'
     Ubuntu or Debian	$ sudo apt-get purge hadoop hue-common impala-shell solr-server 'bigtop-*'

3. Restart all the Cloudera Manager Agents to force an update of the symlinks to point to the newly installed components on each host:

   $ sudo service cloudera-scm-agent restart

Restore Hue Database

1. Go to the Hue service.
2. Select Actions > Stop and click Stop to confirm.
3. Copy the backup from the temporary location to the newly created Hue database directory: /opt/cloudera/parcels/CDH-4.x.0-x.cdh4.x.0.p0.xx/share/hue/desktop.
4. Restart the Hue service.