oozie JAVA Client 编程提交作业

1，eclipse环境搭建

在eclipse中新建一个JAVA工程，导入必要的依赖包，目前用到的有:

其次编写JAVA 程序提交Oozie作业，这里可参考：oozie官方参考文档

在运行提交程序前，首先需要把相应的程序打成jar包，定义好workflow.xml，再把它们上传到HDFS中。然后在程序中指定作业的属性，这里我是直接用的oozie-examples.tar.gz中的示例。

部分代码参考如下：

OozieClient wc = new OozieClient("http://192.168.121.35:11000/oozie");
        
        //create workflow job configuration 
        Properties conf = wc.createConfiguration();
        conf.setProperty(OozieClient.APP_PATH, "hdfs://datanode1:8020/user/cdhfive/examples/apps/map-reduce");
        
        //set a workflow parameters
        conf.setProperty("nameNode", "hdfs://datanode1:8020");
        conf.setProperty("jobTracker", "datanode1:8032");
        conf.setProperty("inputDir", "/user/cdhfive/examples/input-data");
//        conf.setProperty("outputDir", "hdfs://192.168.121.35:8020/user/cdhfive/examples/output-data");
        conf.setProperty("outputDir", "/user/cdhfive/examples/output-data");
        conf.setProperty("queueName", "default");
        conf.setProperty("examplesRoot", "examples");
        conf.setProperty("user.name", "cdhfive");

在代码中workflow的参数时需要注意以下几点：

①在workflow.xml中定义的变量需要在程序中进行设置。如workflow.xml中的 ${jobTracker}，则在JAVA程序中需要用语句:

conf.setProperty("jobTracker", "datanode1:8032");设置好。并且value 值要符合相应的格式。

2，作业提交过程中碰到的一些问题及解决：

ⓐError starting action [mr-node]. ErrorType [TRANSIENT], ErrorCode [JA009], Message [JA009: Permission denied: user=hapjin, access=WRITE, inode="/user":hdfs:supergroup:drwxr-xr-x

由于我在本地windows系统上的用户hapjin运行的eclipse应用程序进行的提交，而集群则是远程的虚拟机。因此作业执行时报权限错误。

这里可以在作业提交过程中指定作业的用户名：conf.setProperty("user.name", "cdhfive")

ⓑ变量不能解析的错误：这是因为在workflow.xml中定义了一些变量，如${examplesRoot}，而在JAVA代码中没有给这些变量赋值（conf.setProperty(key,value))。

javax.servlet.jsp.el.ELException: variable [examplesRoot] cannot be resolved

解决：workflow.xml中定义的变量需要在Java代码中使用 conf.setProerty方法指定值。

整个完整的程序代码参考如下：

package test;

import java.util.Properties;

import org.apache.oozie.client.OozieClient;
import org.apache.oozie.client.OozieClientException;
import org.apache.oozie.client.WorkflowJob.Status;

public class CommitJob {
    public static void main(String[] args) {
        //get a OozieClient for local Oozie
        OozieClient wc = new OozieClient("http://192.168.121.35:11000/oozie");
        
        //create workflow job configuration 
        Properties conf = wc.createConfiguration();
        conf.setProperty(OozieClient.APP_PATH, "hdfs://datanode1:8020/user/cdhfive/examples/apps/map-reduce");
        
        //set a workflow parameters
        conf.setProperty("nameNode", "hdfs://datanode1:8020");
             
        conf.setProperty("inputDir", "/user/cdhfive/examples/input-data");
//        conf.setProperty("outputDir", "hdfs://192.168.121.35:8020/user/cdhfive/examples/output-data");
        conf.setProperty("outputDir", "/user/cdhfive/examples/output-data");
        conf.setProperty("queueName", "default");
        conf.setProperty("examplesRoot", "examples");
        conf.setProperty("user.name", "cdhfive");
        
        //submit and start the workflow job
        try{
            String jobId = wc.run(conf);
            System.out.println("Workflow job submitted");
            
            //wait until the workflow job finishes
            while(wc.getJobInfo(jobId).getStatus() == Status.RUNNING){
                System.out.println("Workflow job running...");
                try{
                    Thread.sleep(10*1000);
                }catch(InterruptedException e){e.printStackTrace();}
            }
            System.out.println("Workflow job completed!");
            System.out.println(wc.getJobId(jobId));
        }catch(OozieClientException e){e.printStackTrace();}
        
    }
}

运行结果截图：

3，Oozie处理错误的方式

If the failure is of transient nature, Oozie will perform retries after a pre-defined time interval. The number of retries and timer interval for a type of action must be pre-configured at Oozie level. Workflow jobs can override such configuration.

Examples of a transient failures are network problems or a remote system temporary unavailable.

If the failure is of non-transient nature, Oozie will suspend the workflow job until an manual or programmatic intervention resumes the workflow job and the action start or end is retried.

如果作业是临时失败的，如因为网络原因或远程系统临时不可用，此时OOzie将会以预定的时间间隔重启作业。若作业不是临时失败的，Oozie将会挂起作业，此时需要手工或程序的干预才能恢复作业的运行。