The Oozie Service

Adding Schema to Oozie

For CDH 4.x Cloudera Manager configures Oozie to recognize only the schema available in CDH 4.0.0, even though more were added later. If you want to use any additional schema, do the following:

In the Cloudera Manager Admin Console, go to the Oozie service.
Select Configuration > View and Edit.
Click Oozie Server Default Group.
Select the Oozie SchemaService Workflow Extension Schemas property.
Enter the desired schema from Oozie Schema, appending .xsd to each entry.
Click Save Changes to commit the changes.
Restart the Oozie service.

Table 1. Oozie Schema
	CDH 5.0.0	CDH 4.6.0-4.3.0	CDH 4.2.0	CDH 4.1.0	CDH 4.0.0
distcp	distcp-action-0.1 distcp-action-0.2	distcp-action-0.1 distcp-action-0.2	distcp-action-0.1 distcp-action-0.2	distcp-action-0.1	distcp-action-0.1
email	email-action-0.1	email-action-0.1	email-action-0.1	email-action-0.1	email-action-0.1
hive	hive-action-0.2 hive-action-0.3 hive-action-0.4 hive-action-0.5	hive-action-0.2 hive-action-0.3 hive-action-0.4 hive-action-0.5	hive-action-0.2 hive-action-0.3 hive-action-0.4	hive-action-0.2 hive-action-0.3 hive-action-0.4	hive-action-0.2
oozie-bundle	oozie-bundle-0.1 oozie-bundle-0.2	oozie-bundle-0.1 oozie-bundle-0.2	oozie-bundle-0.1 oozie-bundle-0.2	oozie-bundle-0.1 oozie-bundle-0.2	oozie-bundle-0.1
oozie-coordinator	oozie-coordinator-0.1 oozie-coordinator-0.2 oozie-coordinator-0.3 oozie-coordinator-0.4	oozie-coordinator-0.1 oozie-coordinator-0.2 oozie-coordinator-0.3 oozie-coordinator-0.4	oozie-coordinator-0.1 oozie-coordinator-0.2 oozie-coordinator-0.3 oozie-coordinator-0.4	oozie-coordinator-0.1 oozie-coordinator-0.2 oozie-coordinator-0.3 oozie-coordinator-0.4	oozie-coordinator-0.1 oozie-coordinator-0.2 oozie-coordinator-0.3
oozie-sla	oozie-sla-0.1 oozie-sla-0.2	oozie-sla-0.1	oozie-sla-0.1	oozie-sla-0.1	oozie-sla-0.1
oozie-workflow	oozie-workflow-0.1 oozie-workflow-0.2 oozie-workflow-0.2.5 oozie-workflow-0.3 oozie-workflow-0.4 oozie-workflow-0.4.5 oozie-workflow-0.5	oozie-workflow-0.1 oozie-workflow-0.2 oozie-workflow-0.2.5 oozie-workflow-0.3 oozie-workflow-0.4 oozie-workflow-0.4.5	oozie-workflow-0.1 oozie-workflow-0.2 oozie-workflow-0.2.5 oozie-workflow-0.3 oozie-workflow-0.4	oozie-workflow-0.1 oozie-workflow-0.2 oozie-workflow-0.2.5 oozie-workflow-0.3 oozie-workflow-0.4	oozie-workflow-0.1 oozie-workflow-0.2 oozie-workflow-0.2.5 oozie-workflow-0.3
shell	shell-action-0.1 shell-action-0.2 shell-action-0.3	shell-action-0.1 shell-action-0.2 shell-action-0.3	shell-action-0.1 shell-action-0.2 shell-action-0.3	shell-action-0.1 shell-action-0.2 shell-action-0.3	shell-action-0.1
sqoop	sqoop-action-0.2 sqoop-action-0.3 sqoop-action-0.4	sqoop-action-0.2 sqoop-action-0.3 sqoop-action-0.4	sqoop-action-0.2 sqoop-action-0.3 sqoop-action-0.4	sqoop-action-0.2 sqoop-action-0.3 sqoop-action-0.4	sqoop-action-0.2
ssh	ssh-action-0.1 ssh-action-0.2	ssh-action-0.1 ssh-action-0.2	ssh-action-0.1	ssh-action-0.1	ssh-action-0.1

Enabling the Oozie Web Console

Download ext-2.2. Extract the contents of the file to /var/lib/oozie/.
In the Cloudera Manager Admin Console, go to the Oozie service.
Select Configuration > View and Edit.
Check Enable Oozie server web console.
Click Save Changes to commit the changes.
Restart the Oozie service.

Using an External Database for Oozie

The default database for Oozie is Derby. If necessary, you can configure Oozie to use an external database. The databases that Oozie supports are listed at:

In the Cloudera Manager Admin Console, go to the Oozie service.
Select Configuration > View and Edit.
Expand Oozie Server Default Group and click Database.
Specify the settings for Oozie Server database type, Oozie Server database name, Oozie Server database host, Oozie Server database user, and Oozie Server database password.
Click Save Changes to commit the changes.
Restart the Oozie service.

Enabling SSL for Oozie

You can enable SSL for communication with the Oozie server by setting the "Use SSL" property in your Oozie security configuration, and adding the keystore file location and password.

In the Cloudera Manager Admin Console, go to the Oozie service.
Select Configuration > View and Edit.
Under the Service-Wide > Security category, check Use SSL and save your changes.
Under the Oozie Server Default Group > Security category, type the path to the keystore file in the Oozie SSL Keystore File field, type the password into the Oozie SSL Keystore Password field
Click Save Changes to commit the changes.
Restart the Oozie service.

Configuring Oozie High Availability

You can use Cloudera Manager to configure CDH 5 or later for Oozie High Availability (HA). For more information, see the About Oozie High Availability in the CDH High Availability Guide.

Important: Enabling or disabling HA will cause the previous monitoring history to become unavailable.

Requirements

The requirements for Oozie High Availability are:

An external database that supports multiple concurrent connections. The default Derby database does not support multiple concurrent connections. In addition, the database should be configured for HA (for example Oracle RAC, MySQL Cluster). If the database is not HA and fails all Oozie servers will stop working. HA will still work with a non-HA database, but then the database then becomes the single point of failure.
On all the hosts where Oozie servers are going to run, the JDBC JAR should be placed in /var/lib/oozie/ or in the location referenced by the environment variables CLOUDERA_MYSQL_CONNECTOR_JAR or CLOUDERA_ORACLE_CONNECTOR_JAR if using MySQL or Oracle respectively.
ZooKeeper, which is used for distributed locks to coordinate the Oozie servers accessing the database at the same time and service discovery so that the Oozie servers can locate each other for log aggregation.
A load balancer that
- Provides a single entry point for clients so they don’t have to choose between, or even be aware of, multiple Oozie servers
- Receives callbacks from JobTracker when a job is done. Callbacks are best-effort and used as “hints”, so eventually, default is ≤ 10min, the other Oozie servers would go and contact the JobTracker regardless of whether or not the callback went through and nothing would be lost or stuck. The load balancer should be HA as well. The load balancer should configured for round robin and not take into account the actual load on any of the Oozie servers.

Enabling Oozie High Availability

Ensure that the requirements are satisfied.
In the Cloudera Manager Admin Console, go to the Oozie service.
Select Actions > Enable High Availability. A screen showing the hosts that are eligible to run an additional Oozie server displays. The host where the current Oozie server is running is not available as a choice.
Select the host where you want the additional Oozie server to be installed, and click Continue.
Specify the host and port of the Oozie load balancer, and click Continue. Cloudera Manager executes a set of commands that stops Oozie servers, add another Oozie server, initializes the Oozie server High Availability state in ZooKeeper, configures Hue to reference the Oozie load balancer, and restarts the Oozie servers and dependent services.

Disabling Oozie High Availability

In the Cloudera Manager Admin Console, go to the Oozie service.
Select Actions > Disable High Availability. A screen showing the hosts running the Oozie servers displays.
Select which Oozie server (host) you want to remain as the single Oozie server, and click Continue. Cloudera Manager executes a set of commands that stop the Oozie service, removes the additional Oozie servers, configures Hue to reference the Oozie service, and restarts the Oozie service and dependent services.