oozie

With job properties in place, a command presented at Listing 4 can be used to run an Oozie workflow.

Externalizing java class execution creates additional network traffic for synchronizing this execution with Oozie server.

This can be useful when Oozie worklows are either part of a specific application or a larger enterprise process.

Once a workflow is deployed, an Oozie provides a command line utility [5] can be used to submit, start and manipulate a workflow.

We also described deployment and configuration of workflow for Oozie and tools for starting, stoping and monitoring Oozie workflows.

Oozie coordinator support creation of such data Application pipelines.

An Oozie console (Figure 2) can be used to watch the progress and results of workflow execution.

Custom action nodes allow to extend Oozie' language with additional actions (verbs).

In the next article we will look at a more complex example, allowing us to discuss more Oozie features.

WorkflowAction provides Oozie' definition of the current action.

Here, first workflow client is initialized with Oozie server URL.

Oozie guarantees that both actions will be submitted to Job tracker in parallel.

The Oozie Coordinator system allows the user to define workflow execution schedules based on these parameters.

They have also released Oozie, a workflow engine for Hadoop, which has become the de-facto ETL standard at Yahoo.

See this link for Oozie installation.

In this article we have shown how to extend Oozie by creating custom action executors.

In our previous articles [1, 2] we described Oozie workflow server and presented several workflow examples.

This is done via a callback from the action or Oozie polling for the action status.

In this article we will introduce Oozie and some of the ways it can be used.

Check method, which is used by Oozie to check action's status.

Take a look at Oozie source code [4] to see how this method is implemented in the existing Oozie action handlers

Externalizing execution make Oozie engine more light weight, which allows it to support more concurrently running processes

Oozie is a Java Web-Application that runs in a Java servlet-container - Tomcat and uses a database to store

All Oozie action executors, which are part of Oozie distribution are implemented by extending this class

A very simple Oozie java client invoking described above process is presented at Listing 5

To automate this process we have created a simple Oozie Workflow (Listing 1)

Now we need to register information about custom executor with Oozie runtime. This is done by extending oozie-site. xml

Listing 6: Passing parameters to Oozie

Oozie console can also be used to get details of the job execution, for example job log [8] (Figure 3)