How does this alter HDFS block storage?
A slave node in your cluster has 4 TB hard drives installed (4 x 2TB). The DataNode is configured
to store HDFS blocks on all disks. You set the value of the dfs.datanode.du.reserved parameter to
100 GB. How does this alter HDFS block storage?
What do you have to do on the cluster to allow the worker node to join, and start sorting HDFS blocks?
You have installed a cluster HDFS and MapReduce version 2 (MRv2) on YARN. You have no
dfs.hosts entry(ies) in your hdfs-site.xml configuration file. You configure a new worker node by
setting fs.default.name in its configuration files to point to the NameNode on your cluster, and you
start the DataNode daemon on that worker node. What do you have to do on the cluster to allow
the worker node to join, and start sorting HDFS blocks?
What two processes must you do if you are running a Hadoop cluster with a single NameNode and six DataNodes
What two processes must you do if you are running a Hadoop cluster with a single NameNode
and six DataNodes, and you want to change a configuration parameter so that it affects all six
DataNodes.
How will the cluster handle the replication of file in this situation?
You use the hadoop fs –put command to add a file “sales.txt” to HDFS. This file is small enough
that it fits into a single block, which is replicated to three nodes in your cluster (with a replication
factor of 3). One of the nodes holding this file (a single block) fails. How will the cluster handle the
replication of file in this situation?
What command you enter?
What happens when you issue the third command?
Assume you have a file named foo.txt in your local directory. You issue the following three
commands:
Hadoop fs –mkdir input
Hadoop fs –put foo.txt input/foo.txt
Hadoop fs –put foo.txt input
What happens when you issue the third command?
How must you format underlying file system of each DataNode?
You are configuring a server running HDFS, MapReduce version 2 (MRv2) on YARN running
Linux. How must you format underlying file system of each DataNode?
What should you do/
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/
How many Mappers will run?
On a cluster running MapReduce v2 (MRv2) on YARN, a MapReduce job is given a directory of 10
plain text files as its input directory. Each file is made up of 3 HDFS blocks. How many Mappers
will run?
What should you do?
You’re upgrading a Hadoop cluster from HDFS and MapReduce version 1 (MRv1) to one running
HDFS and MapReduce version 2 (MRv2) on YARN. You want to set and enforce version 1 (MRv1)
to one running HDFS and MapReduce version 2 (MRv2) on YARN. You want to set and enforce a
block size of 128MB for all new files written to the cluster after upgrade. What should you do?