Let us run simple Map Reduce Job and see what happens. We will be using Hadoop examples that come as part of the setup process itself. We can use Hadoop jar or yarn jar to submit map reduce job as YARN application. Let us run an application called randomtextwriter which will generate 10 GB of …
Here are the steps involved in setting up YARN + MR2 using Cloudera Manager. There are 2 different processing engines that can be configured using Cloudera Manager (Map Reduce which is a legacy framework and YARN + MR2). We don’t need to worry much about the legacy framework. Choose the drop-down of cluster Cluster 1 …
So far, we have seen setting up Zookeeper and HDFS, now we will see how to setup YARN which stands for Yet Another Resource Negotiator. YARN (MRv2) introduces newer daemons that are responsible for job scheduling/monitoring and resource management. Setup YARN + MR2 Run Simple Map Reduce Job Components of YARN and MR2 Configuration Files …
There are several commands to perform administration using CLI. We need to use HDFS super user to manage HDFS cluster using commands. In our case it is hdfs itself. Formatting Namenode Rolling Edits Save Namespace (create fsimage) Enter or Leave Safemode Running balancer Running file system utility (fsck) and many more By this time you …
HDFS Snapshots are read-only point-in-time copies of the file system. Snapshots can be taken on a subtree of the file system or the entire file system. Some common use cases of snapshots are data backup, protection against user errors and disaster recovery. It does not copy actual data. It will keep track of changes to …
Now let us have a look at HDFS usage commands and also commands used to get the metadata. hadoop fs -df – to get details about the amount of storage used by HDFS. Use -s to get summarized information and -h to get information in readable format. hadoop fs -du – to get the size …
