Setting Up Oozie with an Alternate Tomcat

Use the addtowar.sh script to prepare the Oozie server only if Oozie will run with a different servlet container than the embedded Tomcat provided with the distribution.

The addtowar.sh script adds Hadoop JARs, JDBC JARs and the ExtJS library to the Oozie WAR file.

The addtowar.sh script options are:

 Usage  : addtowar <OPTIONS>
 Options: -inputwar INPUT_OOZIE_WAR
          -outputwar OUTPUT_OOZIE_WAR
          [-hadoop HADOOP_VERSION HADOOP_PATH]
          [-extjs EXTJS_PATH]
          [-jars JARS_PATH] (multiple JAR path separated by ':')

The original oozie.war file is in the Oozie server installation directory.

After the Hadoop JARs and the ExtJS library has been added to the oozie.war file Oozie is ready to run.

Delete any previous deployment of the oozie.war from the servlet container (if using Tomcat, delete =oozie.war= and oozie directory from Tomcat's webapps/ directory)

Deploy the prepared oozie.war file (the one that contains the Hadoop JARs adn the ExtJS library) in the servlet container (if using Tomcat, copy the prepared oozie.war file to Tomcat's webapps/ directory).

IMPORTANT: Only one Oozie instance can be deployed per Tomcat instance.

Oozie Configuration Properties

All Oozie configuration properties and their default values are defined in the oozie-default.xml file.

Oozie resolves configuration property values in the following order:

• If a Java System property is defined, it uses its value
• Else, if the Oozie configuration file (=oozie-site.xml=) contains the property, it uses its value
• Else, it uses the default value documented in the oozie-default.xml file

NOTE: The oozie-default.xml file found in Oozie's conf/ directory is not used by Oozie, it is there for reference purposes only.

Logging Configuration

By default, Oozie log configuration is defined in the oozie-log4j.properties configuration file.

If the Oozie log configuration file changes, Oozie reloads the new settings automatically.

By default, Oozie logs to Oozie's logs/ directory.

Oozie logs in 4 different files:

• oozie.log: web services log streaming works from this log
• oozie-ops.log: messages for Admin/Operations to monitor
• oozie-instrumentation.log: intrumentation data, every 60 seconds (configurable)
• oozie-audit.log: audit messages, workflow jobs changes

The embedded Tomcat and embedded Derby log files are also written to Oozie's logs/ directory.

Oozie User Authentication Configuration

Oozie supports Kerberos HTTP SPNEGO authentication, pseudo/simple authentication and anonymous access for client connections.

Anonymous access (*default*) does not require the user to authenticate and the user ID is obtained from the job properties on job submission operations, other operations are anonymous.

Pseudo/simple authentication requires the user to specify the user name on the request, this is done by the PseudoAuthenticator class by injecting the user.name parameter in the query string of all requests. The user.name parameter value is taken from the client process Java System property user.name .

Kerberos HTTP SPNEGO authentication requires the user to perform a Kerberos HTTP SPNEGO authentication sequence.

If Pseudo/simple or Kerberos HTTP SPNEGO authentication mechanisms are used, Oozie will return the user an authentication token HTTP Cookie that can be used in later requests as identy proof.

Oozie uses Apache Hadoop-Auth (Java HTTP SPENGO) library for authentication. This library can be extended to support other authentication mechanisms.

Oozie user authentication is configured using the following configuration properties (default values shown):

  oozie.authentication.type=simple
  oozie.authentication.token.validity=36000
  oozie.authentication.signature.secret=
  oozie.authentication.cookie.domain=
  oozie.authentication.simple.anonymous.allowed=true
  oozie.authentication.kerberos.principal=HTTP/localhost@${local.realm}
  oozie.authentication.kerberos.keytab=${oozie.service.HadoopAccessorService.keytab.file}

The type defines authentication used for Oozie HTTP endpoint, the supported values are: simple | kerberos | #AUTHENTICATION_HANDLER_CLASSNAME#.

The token.validity indicates how long (in seconds) an authentication token is valid before it has to be renewed.

The signature.secret is the signature secret for signing the authentication tokens. If not set a random secret is generated at startup time.

The oozie.authentication.cookie.domain The domain to use for the HTTP cookie that stores the authentication token. In order to authentiation to work correctly across all Hadoop nodes web-consoles the domain must be correctly set.

The simple.anonymous.allowed indicates if anonymous requests are allowed. This setting is meaningful only when using 'simple' authentication.

The kerberos.principal indicates the Kerberos principal to be used for HTTP endpoint. The principal MUST start with 'HTTP/' as per Kerberos HTTP SPNEGO specification.

The kerberos.keytab indicates the location of the keytab file with the credentials for the principal. It should be the same keytab file Oozie uses for its Kerberos credentials for Hadoop.

Oozie Hadoop Authentication Configuration

Oozie works with Hadoop versions which support Kerberos authentication.

Oozie Hadoop authentication is configured using the following configuration properties (default values shown):

  oozie.service.HadoopAccessorService.kerberos.enabled=false
  local.realm=LOCALHOST
  oozie.service.HadoopAccessorService.keytab.file=${user.home}/oozie.keytab
  oozie.service.HadoopAccessorService.kerberos.principal=${user.name}/localhost@{local.realm}

The above default values are for a Hadoop 0.20 secure distribution (with support for Kerberos authentication).

To enable Kerberos authentication, the following property must be set:

  oozie.service.HadoopAccessorService.kerberos.enabled=true

When using Kerberos authentication, the following properties must be set to the correct values (default values shown):

  local.realm=LOCALHOST
  oozie.service.HadoopAccessorService.keytab.file=${user.home}/oozie.keytab
  oozie.service.HadoopAccessorService.kerberos.principal=${user.name}/localhost@{local.realm}

IMPORTANT: When using Oozie with a Hadoop 20 with Security distribution, the Oozie user in Hadoop must be configured as a proxy user.

User ProxyUser Configuration

Oozie supports impersonation or proxyuser functionality (identical to Hadoop proxyuser capabilities and conceptually similar to Unix 'sudo').

Proxyuser enables other systems that are Oozie clients to submit jobs on behalf of other users.

Because proxyuser is a powerful capability, Oozie provides the following restriction capabilities (similar to Hadoop):

• Proxyuser is an explicit configuration on per proxyuser user basis.
• A proxyuser user can be restricted to impersonate other users from a set of hosts.
• A proxyser user can be restricted to impersonate users belonging to a set of groups.

There are 2 configuration properties needed to set up a proxyuser:

• oozie.service.ProxyUserService.proxyuser.#USER#.hosts: hosts from where the user #USER# can impersonate other users.
• oozie.service.ProxyUserService.proxyuser.#USER#.groups: groups the users being impersonated by user #USER# must belong to.

Both properties support the '*' wildcard as value. Although this is recommended only for testing/development.

User Authorization Configuration

Oozie has a basic authorization model:

• Users have read access to all jobs
• Users have write access to their own jobs
• Users have write access to jobs based on an Access Control List (list of users and groups)
• Users have read access to admin operations
• Admin users have write access to all jobs
• Admin users have write access to admin operations

If security is disabled all users are admin users.

Oozie security is set via the following configuration property (default value shown):

  oozie.service.AuthorizationService.security.enabled=false

NOTE: the old ACL model where a group was provided is still supported if the following property is set in oozie-site.xml :

  oozie.service.AuthorizationService.default.group.as.acl=true

Admin users are determined from the list of admin groups, specified in oozie.service.AuthorizationService.admin.groups property. Use commas to separate multiple groups, spaces, tabs and ENTER characters are trimmed.

If the above property for admin groups is not set, then the admin users are the users specified in the conf/adminusers.txt file. The syntax of this file is:

• One user name per line
• Empty lines and lines starting with '#' are ignored

Oozie System ID Configuration

Oozie has a system ID that is is used to generate the Oozie temporary runtime directory, the workflow job IDs, and the workflow action IDs.

Two Oozie systems running with the same ID will not have any conflict but in case of troubleshooting it will be easier to identify resources created/used by the different Oozie systems if they have different system IDs (default value shown):

  oozie.system.id=oozie-${user.name}

Fine Tuning an Oozie Server

Refer to the oozie-default.xml for details.