Book Image

Hadoop 2.x Administration Cookbook

By : Aman Singh
Book Image

Hadoop 2.x Administration Cookbook

By: Aman Singh

Overview of this book

Hadoop enables the distributed storage and processing of large datasets across clusters of computers. Learning how to administer Hadoop is crucial to exploit its unique features. With this book, you will be able to overcome common problems encountered in Hadoop administration. The book begins with laying the foundation by showing you the steps needed to set up a Hadoop cluster and its various nodes. You will get a better understanding of how to maintain Hadoop cluster, especially on the HDFS layer and using YARN and MapReduce. Further on, you will explore durability and high availability of a Hadoop cluster. You’ll get a better understanding of the schedulers in Hadoop and how to configure and use them for your tasks. You will also get hands-on experience with the backup and recovery options and the performance tuning aspects of Hadoop. Finally, you will get a better understanding of troubleshooting, diagnostics, and best practices in Hadoop administration. By the end of this book, you will have a proper understanding of working with Hadoop clusters and will also be able to secure, encrypt it, and configure auditing for your Hadoop clusters.
Table of Contents (20 chapters)
Hadoop 2.x Administration Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
Index

Hive troubleshooting


In this recipe, we will look at Hive troubleshooting steps and important keywords in the logs, which can help us to identify issues.

Getting ready

For this recipe, the user must have completed the Operating Hive with ZooKeeper recipe in Chapter 7, Data Ingestion and Workflow and have a basic understanding of database connectivity.

How to do it...

  1. Connect to the edge1.cyrus.com Edge node and switch to user hadoop.

  2. The Hive query logs location is defined by hive.querylog.location and the Hive server2 logs is defined by hive.server2.logging.operation.log.location.

  3. As an example, if I try to query a table that does not exist, we can see the errors in the Hive log, as shown in the following screenshot:

  4. Make it a good habit to read logs to troubleshoot, as logs will give hints about errors.

  5. Make sure Hive is able to connect to the Hive metastore. To verify this, first connect manually, as shown here:

    $ mysql –u Hadoop –h master1.cyrus.com -p
    
  6. Make sure the user used in Hive Hadoop...