Oozie-JavaAction

Java Acon

目录

1.官网解释..................................................................................................................................... 1

2.JavaAcon 使用........................................................................................................................... 4

2.1 编写自定义功能的 main 函数.......................................................................................... 4

2.2 编写 workow.xml 文件.................................................................................................... 6

2.3 编写 job.properes 文件.................................................................................................. 7

2.4 部署.................................................................................................................................. 7

action.

Thejavaaction has to be congured with the job-tracker, name-node, main Java class, JVM options and

arguments.

To indicate anokaction transition, the main Java class must complete gracefully themainmethod

invocation.

To indicate anerroraction transition, the main Java class must throw an exception.

The main Java class must not callSystem.exit(int n)as this will make thejavaaction to do

anerrortransition regardless of the used exit code.

Ajavaaction can be congured to perform HDFS les/directories cleanup before starting the Java

application. This capability enables Oozie to retry a Java application in the situation of a transient or non-

Inline property values can be parameterized (templatized) using EL expressions.

The Hadoopmapred.job.tracker(=job-tracker=) andfs.default.name(=name-node=)

properties must not be present in thejob-xmland in the inline conguration.

As withmap-reduceandpigactions, it is possible to add les and archives to be available to the

Java application. Refer to section [#FilesAchives][Adding Files and Archives for the Job].

Thecapture-outputelement can be used to propagate values back into Oozie context, which can

then be accessed via EL-functions. This needs to be written out as a java properties format le. The lename

is obtained via a System property specied by the

constantJavaMainMapper.OOZIE_JAVA_MAIN_CAPTURE_OUTPUT_FILE

IMPORTANT:In order for a Java action to succeed on a secure cluster, it must propagate the Hadoop

IMPORTANT:Because the Java application is run from within a Map-Reduce job, from Hadoop 0.20. onwards

a queue must be assigned to it. The queue name must be specied as a conguration property.

Syntax:

<work&ow-app name="[WF-DEF-NAME]" xmlns="uri:oozie:work&ow:0.1">

...

<action name="[NODE-NAME]">

<java>

<job-tracker>[JOB-TRACKER]</job-tracker>

<name-node>[NAME-NODE]</name-node>

<prepare>