Hadoop

Note: This post is part of the CCA Administrator Exam (CCA131) objectives series In the exam, you may be asked to create a home directory for an existing local user onto HDFS. You may further be asked to set a specific ownership or permission to the home directory. The process basically involves: Create a local user if not already present Create a home directory into HDFS for the user Assign appropriate ownership and permissions to the home directory 1. Create a local user Please … [Read more...] about CCA131 – Create an HDFS user’s home directory

Note: This post is part of the CCA Administrator Exam (CCA131) objectives series The basis for Hadoop Access Control Lists is POSIX ACLs, available on the Linux filesystem. These ACLs allow you to link a set of permissions to a file or directory that is not limited to just one user and a group who owns the file. The HDFS ACLs give you a fine-grained file permissions model that is suitable for a large enterprise where the data stored on the Hadoop cluster should be accessible to some groups … [Read more...] about CCA 131 – Configure HDFS ACLs

Note: This post is part of the CCA Administrator Exam (CCA131) objectives series In a long-running cluster, there might be an unequal distribution of data across Datanodes. This could be due to failures of nodes or the addition of nodes to the cluster. To make sure that the data is equally distributed across Datanodes, it is important to use Hadoop balancer to redistribute the blocks. How rebalancing works - HDFS rebalancer reviews data block placement on nodes and adjusts the blocks to … [Read more...] about CCA 131 – Rebalance the cluster

Note: This post is part of the CCA Administrator Exam (CCA131) objectives series Cloudera Manager makes it very simple to add and remove hosts in a cluster. All host management operations in Cloudera Manager are done from the Hosts screen. In this post, we will go through the steps of Commissioning and decommissioning a host in the CDH cluster. There will always be failures in clusters, such as hardware issues or a need to upgrade nodes. This should be done in a graceful manner, without … [Read more...] about CCA 131 – Commission/decommission a node

Note: This post is part of the CCA Administrator Exam (CCA131) objectives series To start with we have just installed few services like HDFS, YARN, and zookeeper in our CDH setup. The Cloudera Manager enables you to add any other service later on. As a part of the exam, you may be asked to add a new service to the CDH cluster. The process remains fairly simple for all the services. I have deleted the YARN service and will outline the steps to add the service below. Adding a new service … [Read more...] about CCA 131 – Add a service using Cloudera Manager

Note: This post is part of the CCA Administrator Exam (CCA131) objectives series Cloudera Manager makes it very simple to add and remove hosts in a cluster. All host management operations in Cloudera Manager are done from the Hosts screen. In this section, we will go through the steps of adding a new host to the cluster. There are 2 ways to add a new host using Cloudera Manager: 1. Let Cloudera Manager install the Cloudera Manager agent and other parcels etc. 2. Manually install the … [Read more...] about CCA 131 – Add a new node to an existing cluster