ContainerLaunchContext.setResource() missing of hadoop yarn - hadoop

Question

http://hadoop.apache.org/docs/r2.1.0-beta/hadoop-yarn/hadoop-yarn-site/WritingYarnApplications.html
I am try to make the example work well from the above link.but I can't compile the code below
Resource capability = Records.newRecord(Resource.class);
capability.setMemory(512);
amContainer.setResource(capability);
// Set the container launch content into the
// ApplicationSubmissionContext
appContext.setAMContainerSpec(amContainer);
amContainer is ContainerLaunchContext and my hadoop version is 2.1.0-beta.
I did some investigation. I found there's no method "setResource" in ContainerLaunchContext
I have 3 question about this
1) the method has been removed or something?
2) if the method has been removed, how can I do now?
3) is there any doc about yarn, because I found the doc in website is very easy, I hope I can get a manual or something. for example,
capability.setMemory(512);
I don't know it's 512k or 512M according comments in code.

Answer 1

This is actually proper solution to the question. Previous answer might cause incorrect execution !!!
#Dyin I couldn't fit it in the comment ;) Validated for 2.2.0 and 2.3.0
Driver setting up resources for AppMaster:
ApplicationSubmissionContext appContext = app.getApplicationSubmissionContext();
ApplicationId appId = appContext.getApplicationId();
appContext.setApplicationName(this.appName);
// Set up the container launch context for the application master
ContainerLaunchContext amContainer = Records.newRecord(ContainerLaunchContext.class);
Resource capability = Records.newRecord(Resource.class);
capability.setMemory(amMemory);
appContext.setResource(capability);
appContext.setAMContainerSpec(amContainer);
Priority pri = Records.newRecord(Priority.class);
pri.setPriority(amPriority);
appContext.setPriority(pri);
appContext.setQueue(amQueue);
// Submit the application to the applications manager
yarnClient.submitApplication(appContext); // this.yarnClient = YarnClient.createYarnClient();
In ApplicationMaster this is how you should specify resources for containers (workers).
private AMRMClient.ContainerRequest setupContainerAskForRM() {
// setup requirements for hosts
// using * as any host will do for the distributed shell app
// set the priority for the request
Priority pri = Records.newRecord(Priority.class);
pri.setPriority(requestPriority);
// Set up resource type requirements
// For now, only memory is supported so we set memory requirements
Resource capability = Records.newRecord(Resource.class);
capability.setMemory(containerMemory);
AMRMClient.ContainerRequest request = new AMRMClient.ContainerRequest(capability, null, null,
pri);
return request;
}
Some run() or main() method in your AppMaster
AMRMClientAsync.CallbackHandler allocListener = new RMCallbackHandler();
resourceManager = AMRMClientAsync.createAMRMClientAsync(1000, allocListener);
resourceManager.init(conf);
resourceManager.start();
for (int i = 0; i < numTotalContainers; ++i) {
AMRMClient.ContainerRequest containerAsk = setupContainerAskForRM();
resourceManager.addContainerRequest(containerAsk); //
}
Launching containers
You can use the original answer solution (java cmd), but it's just a cherry on top. It should work anyway.

Answer 2

You can set memory available to ApplicationMaster via commend. As such:
// Set the necessary command to execute the application master
Vector<CharSequence> vargs = new Vector<CharSequence>(30);
...
vargs.add("-Xmx" + amMemory + "m"); // notice "m" indicating megabytes, you can use also -Xms combined with -Xmx
... // transform vargs to String commands
amContainer.setCommands(commands);
This should solve your problem. As for the 3 questions. Yarn is rapidly evolving software. My advice forget documentation, get source code and read it. This will answer a lot of your questions.