YARN vs MapReduce v1 in Hadoop - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the resource manager used in YARN.

Hadoop

Configuration conf = new Configuration();
conf.set("yarn.resourcemanager.address", "[1]");

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Alocalhost:9000

Blocalhost:8032

Clocalhost:50070

Dlocalhost:8088

Attempts:

3 left

💡 Hint

Common Mistakes

Using the NameNode port instead of the resource manager port.

Confusing the web UI port with the resource manager port.

The resource manager in YARN listens on port 8032 by default. This address is used to communicate with the resource manager.

2fill in blank

medium

Complete the code to get the number of map tasks in MapReduce v1.

Hadoop

JobConf conf = new JobConf();
int numMaps = conf.[1]();

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AgetMapTaskCount

BgetNumReduceTasks

CgetNumTasks

DgetNumMapTasks

Attempts:

3 left

💡 Hint

Common Mistakes

Using getNumReduceTasks() instead of map tasks method.

Using a non-existent method like getMapTaskCount().

In MapReduce v1, getNumMapTasks() returns the number of map tasks configured for the job.

3fill in blank

hard

Fix the error in the code to submit a YARN application.

Hadoop

YarnClient yarnClient = YarnClient.createYarnClient();
yarnClient.init(conf);
yarnClient.start();
ApplicationId appId = yarnClient.[1]();

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AgetNewApplication

BcreateApplication

CsubmitApplication

DstartApplication

Attempts:

3 left

💡 Hint

Common Mistakes

Using submitApplication() which does not exist on YarnClient.

Using startApplication() which is not a valid method.

The correct method to create a new application in YARN is getNewApplication(). It returns an ApplicationId for the new app.

4fill in blank

hard

Fill both blanks to create a MapReduce job configuration and set the number of reduce tasks.

Hadoop

Job job = Job.getInstance(conf, "wordcount");
job.setJarByClass([1].class);
job.[2](2);

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AWordCount

BsetNumReduceTasks

CsetReduceTasks

DMain

Attempts:

3 left

💡 Hint

Common Mistakes

Using setReduceTasks() which is not a valid method.

Using a wrong class name like 'Main' if the job class is 'WordCount'.

The class name is usually the main class like WordCount. The method to set reduce tasks is setNumReduceTasks().

5fill in blank

hard

Fill all three blanks to create a YARN container launch context with local resources and environment variables.

Hadoop

ContainerLaunchContext ctx = ContainerLaunchContext.newInstance(
    [1],
    [2],
    [3],
    null,
    null,
    null
);

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AlocalResources

Benv

Ccommands

Dconf

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing the order of arguments.

Passing configuration object instead of commands.

The newInstance method takes local resources, environment variables, and commands as the first three arguments.