Is there any way to kill a Hadoop job itself or send a signal to kill it.
I've read the Configuration settings from jobConf where it says that if a user specify the wrong settings I need to kill the job or throw an error, since map/reduce config method does not allow throwing an exception.
public void configure(JobConf job) {
System.out.println("Inside config start processing");
try {
String strFileName = job.get("hadoop.rules");
LoadFile(strFileName );
} catch (Exception e) {
e.printStackTrace();
//Here i need to write code to kill job
}
}
In the configure() method, just throw a RuntimeException.
Better yet, if possible, you're better off performing your validation step before the job is run.
Just save the state into a boolean variable called kill and evaluate the variable inside the map step and then throw an IOException.
Related
I have 2 jobs where i have to launch the job2 based on the the status of the job1.
is it right to make the following call:
JobExecution jobExecution1 = jobLauncher.run(job1, jobParameters1);
if(jobExecution1.getStatus()== BatchStatus.COMPLETED){
JobExecution jobExecution2 = jobLauncher.run(job2, jobParameters2);
}
i have a doubt that the initial jobexecution1 status might not be final when the condition is checked.
if anyone could explain more about yhis process it would be great
thanks in advance .
It depends on the TaskExecutor implementation that you configure in your JobLauncher:
If the task executor is synchronous, then the first job will be run until completion (either success or failure) before launching the second job. In this case, your code is correct.
If the task executor is asynchronous, then the call JobExecution jobExecution1 = jobLauncher.run(job1, jobParameters1); will return immediately and the status of jobExecution1 would be unknown at that point. This means it is incorrect to check the status of job1 right after launching it as a condition to launch job2 (job1 will be run in a separate thread and could still be running at that point).
By default, Spring Batch configures a synchronous task executor in the JobLauncher.
There are multiple ways. We are using below option by chaining jobs by decider. Below is the code snippet . Please let me know if you face any issues.
public class MyDecider implements JobExecutionDecider {
#Override
public FlowExecutionStatus decide(JobExecution jobExecution, StepExecution stepExecution) {
String exitCode = new Random().nextFloat() < .70f ? "CORRECT":"INCORRECT";
return new FlowExecutionStatus(exitCode);
}
}
#Bean
public JobExecutionDecider myDecider() {
return new MyDecider();
}
#Bean
public Job myTestJob() {
return this.jobBuilderFactory.get("myTestJob")
.start(step1())
.next(step2())
.on("FAILED").to(step3())
.from(step4())
.on("*").to(myDecider())
.on("PRESENT").to(myNextStepOrJob)
.next(myDecider()).on("CORRECT").to(myNextStepOrJob())
.from(myDecider()).on("INCORRECT").to(myNextStepOrJob())
.from(decider())
.on("NOT_PRESENT").to(myNextStepOrJob())
.end()
.build();
}
I am developing a web application using Spring Framework that does some jobs as the application starts up, and these jobs primarily consist of loading data from CSVs and making Java objects out of them.
Currently, I am trying to build a RESTful API using Restlet and Spring framework and one of the queries is supposed to take in a job name as parameter and restart that job even if that job has been marked as COMPLETED, how do I accomplish a job restart? I have tried the spring frameworks' Joboperator interface's startNextInstance() method and have also tried to manually increment the JobParameters so that there is no jobinstancealrradyrunning exception?
Anyone has any code snippet or alternative idea on how to restart a Job in Spring Framework that has been marked as Completed?
Any help would be greatly appreciated, thanks!!
Because of the terms you're using i'm quite certain you're using Spring Batch
In Batch terms you cannot actually restart a COMPLETED instance or execution. Single job instance is identified by job parameters. If you need to run the job again with same parameters, one way would be to include some unique parameter, for example the current timestamp to the JobParameters before launching.
So restarting a completed job would mean starting a new instance of the job with similiar parameters. Here's an slightly modified snippet i've used before that uses JobLauncher and JobRegistry to launch a new job by name:
#Autowired
#Qualifier("asyncJobLauncher")
private JobLauncher asyncJobLauncher;
#Autowired
private JobRegistry jobRegistry;
...
public JobExecution startJob(String jobName) {
Job job;
try {
job = jobRegistry.getJob(jobName);
} catch (NoSuchJobException e) {
// handle invalid job name
}
JobParametersBuilder jobParams = new JobParametersBuilder();
jobParams.addLong("currentTime", System.currentTimeMillis());
// add other relevant parameters
try {
JobExecution jobExecution = asyncJobLauncher.run(job, jobParams.toJobParameters());
return jobExecution;
} catch (JobExecutionAlreadyRunningException e) {
// handle instance already running with given params
} catch (Exception e) {
// handle other errors
}
}
Hope it helps, here's some reading about the subject.
I have a problem implementing a custom asynchronous action in Oozie. My class extends from ActionExecutor, and overwrites the methods initActionType, start, end, check, kill and isCompleted.
In the start method, i want to to start a YARN job, that is implemented through my BiohadoopClient class. To make the call asynchronous, i wrapped the client.run() method in a Callable:
public void start(final Context context, final WorkflowAction action) {
...
Callable<String> biohadoop = new Callable<String>() {
BiohadoopClient client = new BiohadoopClient();
client.run();
}
// submit callable to executor
executor.submit(biohadoop);
// set the start data, according to https://oozie.apache.org/docs/4.0.1/DG_CustomActionExecutor.html
context.setStartData(externalId, callBackUrl, callBackUrl);
...
}
This works fine, and for example when I use my custom action in a fork/join manner, the execution of the actions runs in parallel.
Now, the problem is, that Oozie remains in a RUNNING state for this actions. It seems impossible to change that to a completed state. The check() method is never called by Oozie, the same is true for the end() method. It doesn't help to set the context.setExternalStatus(), context.setExecutionData() and context.setEndData() manually in the Callable (after the client.run() has finished). I tried also to queue manually an ActionEndXCommand, but without luck.
When I wait in the start() method for the Callable to complete, the state gets updated correctly, but the execution in fork/join isn't parallel anymore (which seem logic, as the execution waits for the Callable to complete).
How external clients notify Oozie workflow with HTTP callback didn't help, as using the callback seems to change nothing (well, I can see that it happened in the log files, but beside from that, nothing...). Also, the answer mentioned, that the SSH action runs asynchronously, but I haven't found out how this is done. There is some wrapping inside a Callable, but at the end, the call() method of the Callable is invoked directly (no submission to an Executor).
So far I haven't found any example howto write an asynchronous custom action. Can anybody please help me?
Thanks
Edit
Here are the implementations of initActionType(), start(), check(), end(), the callable implementation can be found inside the start() action.
The callable is submitted to an executor in the start() action, after which its shutdown() method is invoked - so the executor shuts down after the Callable has finished. As next step, context.setStartData(externalId, callBackUrl, callBackUrl) is invoked.
private final AtomicBoolean finished = new AtomicBoolean(false);
public void initActionType() {
super.initActionType();
log.info("initActionType() invoked");
}
public void start(final Context context, final WorkflowAction action)
throws ActionExecutorException {
log.info("start() invoked");
// Get parameters from Node configuration
final String parameter = getParameters(action.getConf());
Callable<String> biohadoop = new Callable<String>() {
#Override
public String call() throws Exception {
log.info("Starting Biohadoop");
// No difference if check() is called manually
// or if the next line is commented out
check(context, action);
BiohadoopClient client = new BiohadoopClient();
client.run(parameter);
log.info("Biohadoop finished");
finished.set(true);
// No difference if check() is called manually
// or if the next line is commented out
check(context, action);
return null;
}
};
ExecutorService executor = Executors.newCachedThreadPool();
biohadoopResult = executor.submit(biohadoop);
executor.shutdown();
String externalId = action.getId();
String callBackUrl = context.getCallbackUrl("finished");
context.setStartData(externalId, callBackUrl, callBackUrl);
}
public void check(final Context context, final WorkflowAction action)
throws ActionExecutorException {
// finished is an AtomicBoolean, that is set to true,
// after Biohadoop has finished (see implementation of Callable)
if (finished.get()) {
log.info("check(Context, WorkflowAction) invoked -
Callable has finished");
context.setExternalStatus(Status.OK.toString());
context.setExecutionData(Status.OK.toString(), null);
} else {
log.info("check(Context, WorkflowAction) invoked");
context.setExternalStatus(Status.RUNNING.toString());
}
}
public void end(Context context, WorkflowAction action)
throws ActionExecutorException {
log.info("end(Context, WorkflowAction) invoked");
context.setEndData(Status.OK, Status.OK.toString());
}
One thing - I can see you are shutting down the executor right after you have submitted the job - executor.shutdown();. That might be causing the issue. Could you please try moving this statement to the end() method instead?
In the end I didn't find a "real" solution to the problem. The solution that worked for me was to implement an action, that invokes the Biohadoop instances in parallel using the Java Executor framework. After the invokation, I wait (still inside the action) for the threads to finish
I've developed a Spring Batch with 10 Step.
How can i execute a specific Step ?
My wish is to passed in JobParameter the Step to execute.
Only the Step specified in JobParameter must be executed.
I searched to use the Decider, but i'm not really satisfied.
There's a better Solution ?
Any idea ?
Thanks a lot.
cordially
The Decider is the correct option for the type of processing you're talking about. I'd be interested in why you were "not really satisfied" by that option?
I had similar use case. I wanted to pass job name and step name as the input and expectation was to execute only that particular step from the job.
I created a Rest API which accepts job name and step name as URL parameters.
Below is the code inside the Rest API. It requires few objects injected into the class.
jobRegistry - instance of MapJobRegistry
jobRepository - instance of jobRepository
jobLauncher - instance of JobLauncher
Job job = null;
Step step = null;
try{
Job job = jobRegistry.getJob(jobName);
if(job instanceof StepLocator){
Step = ((StepLocator)job).getStep(stepName);
}
}catch(NoSuchJobException ex){
throw new Exception("Invalid Job", ex);
}catch(NoSuchStepException ex){
throw new Exception("Invalid Step", ex);
}
if(null == step){
throw new Exception("invalid step");
}
JobBuilderFactory jobBuilder = new JobBuiderFactory(jobRepository);
Job newJob = jobBuilder.get("specific-step-job")
.start(step)
.build();
jobLauncher.run(newJob, jobParameters); //jobParameters relevant for this job
This will dynamically create a new job with name "specific-step-job" and add the specific step instance as the start/only step inside the new Job and executes this job.
Yes, you can test an individual step using JobLauncherTestUtils#launchStep.
Please have a look at section 10.3. Testing Individual Steps
Find a sample code here Spring Batch unit test example
While running a map-reduce job, that has only mapper, I have a counter that counts the number of failed documents .And after all the mappers are done, I want the job to fail if the total number of failed documents are above a fixed fraction. ( I need it in the end because I don't know the total number of documents initially). How can I achieve this without implementing a reduce just for this ?
I know that there are task level cleanup method. But is there any job level cleanup method, that can be used to perform this after all the tasks are done ?
This can be done very easily. Thats the beauty of latest mapreduce API.
The execution of a mapper can be controlled with the help of overriding run method in Mapper class, and same way for the reducer. I do not know the final outcome that you are expecting. But, i have prepared a small example for you. I have
in my mapper class, i have overriden run method and giving you a sample, it iterrupts the execution if the key value is greater than 200 in my code.
public class ReversingMapper extends Mapper<LongWritable, Text, ReverseIntWritable, Text>
{
public final LongWritable border = new LongWritable(100);
#Override
public void run(Context context) throws IOException, InterruptedException {
setup(context);
while (context.nextKeyValue()) {
/* extra code to standard run method started here */
//if(context.getCounter(<ENUM>) > 200 ){} -- you can place your counter check here.
if(context.getCurrentKey().get() > 200 )
{
throw new InterruptedException();
}else
{
/* extra code to standard run method ended here */
map(context.getCurrentKey(), context.getCurrentValue(), context);
}
}
}
and you need to handle in properly in the Driver as well.
} catch (InterruptedException e) {
e.printStackTrace();
System.exit(0);
}
You can have logger and even log a proper message that is required here..
I hope this solves your problem. Let me know if you need any more help.