CCA-505 Online Practice Questions and Answers
Which Yarn daemon or service monitors a Container's per-application resource usage (e.g, memory, CPU)?
A. NodeManager
B. ApplicationMaster
C. ApplicationManagerService
D. ResourceManager
For each YARN Job, the Hadoop framework generates task log files. Where are Hadoop's files stored?
A. In HDFS, In the directory of the user who generates the job
B. On the local disk of the slave node running the task
C. Cached In the YARN container running the task, then copied into HDFS on fob completion
D. Cached by the NodeManager managing the job containers, then written to a log directory on the NameNode
You are configuring your cluster to run HDFS and MapReduce v2 (MRv2) on YARN. Which daemons need to be installed on your clusters master nodes? (Choose Two)
A. ResourceManager
B. DataNode
C. NameNode
D. JobTracker
E. TaskTracker
F. HMaster
You have converted your Hadoop cluster from a MapReduce 1 (MRv1) architecture to a MapReduce 2 (MRv2) on YARN architecture. Your developers are accustomed to specifying map and reduce tasks (resource allocation) tasks when they run jobs. A developer wants to know how specify to reduce tasks when a specific job runs. Which method should you tell that developer to implement?
A. Developers specify reduce tasks in the exact same way for both MapReduce version 1 (MRv1) and MapReduce version 2 (MRv2) on YARN. Thus, executing p mapreduce.job.reduce-2 will specify 2 reduce tasks.
B. In YARN, the ApplicationMaster is responsible for requesting the resources required for a specific job. Thus, executing p yarn.applicationmaster.reduce.tasks-2 will specify that the ApplicationMaster launch two task containers on the worker nodes.
C. In YARN, resource allocation is a function of megabytes of memory in multiple of 1024mb. Thus, they should specify the amount of memory resource they need by executing D mapreduce.reduce.memory-mp-2040
D. In YARN, resource allocation is a function of virtual cores specified by the ApplicationMaster making requests to the NodeManager where a reduce task is handled by a single container (and this a single virtual core). Thus, the developer needs to specify the number of virtual cores to the NodeManager by executing p yarn.nodemanager.cpu-vcores=2
E. MapReduce version 2 (MRv2) on YARN abstracts resource allocation away from the idea of "tasks" into memory and virtual cores, thus eliminating the need for a developer to specify the number of reduce tasks, and indeed preventing the developer from specifying the number of reduce tasks.
Which YARN daemon or service negotiates map and reduce Containers from the Scheduler, tracking their status and monitoring for progress?
A. ResourceManager
B. ApplicationMaster
C. NodeManager
D. ApplicationManager
Your cluster has the following characteristics:
A rack aware topology is configured and on
Replication is not set to 3
Cluster block size is set to 64 MB
Which describes the file read process when a client application connects into the cluster and requests a 50MB file?
A. The client queries the NameNode which retrieves the block from the nearest DataNode to the client and then passes that block back to the client.
B. The client queries the NameNode for the locations of the block, and reads from a random location in the list it retrieves to eliminate network I/O leads by balancing which nodes it retrieves data from at any given time.
C. The client queries the NameNode for the locations of the block, and reads all three copies. The first copy to complete transfer to the client is the one the client reads as part of Hadoop's
speculative execution framework.
D. The client queries the NameNode for the locations of the block, and reads from the first location in the list it receives.
Which three basic configuration parameters must you set to migrate your cluster from MapReduce1 (MRv1) to MapReduce v2 (MRv2)?
A. Configure the NodeManager hostname and enable services on YARN by setting the following property in yarn-site.xml:
B. Configure the number of map tasks per job on YARN by setting the following property in mapredsite.xml:
C. Configure MapReduce as a framework running on YARN by setting the following property in mapredsite.xml:
D. Configure the ResourceManager hostname and enable node services on YARN by setting the following property in yarn-site.xml:
E. Configure a default scheduler to run on YARN by setting the following property in sapred- site.xml:
F. Configure the NodeManager to enable MapReduce services on YARN by adding following property in yarn-site.xml:
Which YARN process runs as "controller O" of a submitted job and is responsible for resource requests?
A. ResourceManager
B. NodeManager
C. JobHistoryServer
D. ApplicationMaster
E. JobTracker
F. ApplicationManager
You observe that the number of spilled records from Map tasks far exceeds the number of map output records. Your child heap size is 1GB and your io.sort.mb value is set to 100 MB. How would you tune your io.sort.mb value to achieve maximum memory to disk I/O ratio?
A. Decrease the io.sort.mb value to 0
B. Increase the io.sort.mb to 1GB
C. For 1GB child heap size an io.sort.mb of 128 MB will always maximize memory to disk I/O
D. Tune the io.sort.mb value until you observe that the number of spilled records equals (or is as close to equals) the number of map output records
A slave node in your cluster has four 2TB hard drives installed (4 x 2TB). The DataNode is configured to store HDFS blocks on the disks. You set the value of the dfs.datanode.du.reserved parameter to 100GB. How does this alter HDFS block storage?
A. A maximum of 100 GB on each hard drive may be used to store HDFS blocks
B. All hard drives may be used to store HDFS blocks as long as atleast 100 GB in total is available on the node
C. 100 GB on each hard drive may not be used to store HDFS blocks
D. 25 GB on each hard drive may not be used to store HDFS blocks