Your cluster implements HDFS High Availability (HA). Your two NameNodes are named nn01 and nn02. What occurs when you execute the command: hdfs haadmin –failover nn01 nn02?

1. A. nn02 is fenced, and nn01 becomes the active NameNode
2. B. nn01 is fenced, and nn02 becomes the active NameNode
3. C. nn01 becomes the standby NameNode and nn02 becomes the active NameNode
4. D. nn02 becomes the standby NameNode and nn01 becomes the active NameNode

Correct Answer: B
failover – initiate a failover between two NameNodes
This subcommand causes a failover from the first provided NameNode to the second. If the first
NameNode is in the Standby state, this command simply transitions the second to the Active statewithout error. If the first NameNode is in the Active state, an attempt will be made to gracefullytransition it to the Standby state. If this fails, the fencing methods (as configured bydfs.ha.fencing.methods) will be attempted in order until one of the methods succeeds. Only afterthis process will the second NameNode be transitioned to the Active state. If no fencing methodsucceeds, the second NameNode will not be transitioned to the Active state, and an error will bereturned.

Which YARN daemon or service negotiations map and reduce Containers from the Scheduler, tracking their status and monitoring progress?

1. A. NodeManager
2. B. ApplicationMaster
3. C. ApplicationManager
4. D. ResourceManager

Correct Answer: B
Reference:http://www.devx.com/opensource/intro-to-apache-mapreduce-2-yarn.html(See resource manager)

You want to node to only swap Hadoop daemon data from RAM to disk when absolutely necessary. What should you do?

1. A. Delete the /dev/vmswap file on the node
2. B. Delete the /etc/swap file on the node
3. C. Set the ram.swap parameter to 0 in core-site.xml
4. D. Set vm.swapfile file on the node
5. E. Delete the /swapfile file on the node

Correct Answer: D

You are migrating a cluster from MApReduce version 1 (MRv1) to MapReduce version 2 (MRv2) on YARN. You want to maintain your MRv1 TaskTracker slot capacities when you migrate. What should you do/

1. A. Configure yarn.applicationmaster.resource.memory-mb and yarn.applicationmaster.resource.cpu-vcores so that ApplicationMaster container allocations match the capacity you require.
2. B. You don’t need to configure or balance these properties in YARN as YARN dynamically balances resource management capabilities on your cluster
3. C. Configure mapred.tasktracker.map.tasks.maximum and mapred.tasktracker.reduce.tasks.maximum ub yarn-site.xml to match your cluster’s capacity set by the yarn-scheduler.minimum-allocation
4. D. Configure yarn.nodemanager.resource.memory-mb and yarn.nodemanager.resource.cpu-vcores to match the capacity you require under YARN for each NodeManager

Correct Answer: D

For each YARN job, the Hadoop framework generates task log file. Where are Hadoop task log files stored?

1. A. Cached by the NodeManager managing the job containers, then written to a log directory on the NameNode
2. B. Cached in the YARN container running the task, then copied into HDFS on job completion
3. C. In HDFS, in the directory of the user who generates the job
4. D. On the local disk of the slave mode running the task

Correct Answer: D