Amazon Elastic MapReduce
Developer Guide

View HBase Log Files

As part of its operation, HBase writes log files with details about configuration settings, daemon actions, and exceptions. These log files can be useful for debugging issues with HBase as well as for tracking performance.

If you configure your cluster to persist log files to Amazon S3, you should know that logs are written to Amazon S3 every five minutes, so there may be a slight delay for the latest log files to be available.

To view HBase logs on the master node

  • You can view the current HBase logs by using SSH to connect to the master node, and navigating to the mnt/var/log/hbase directory. These logs will not be available after the cluster ends unless you enable logging to Amazon S3 when the cluster is launched. For information about how to connect to the master node using SSH see, Connect to the Master Node Using SSH. After you have connected to the master node using SSH, you can navigate to the log directory using a command like the following.

    cd mnt/var/log/hbase

To view HBase logs on Amazon S3

  • To access HBase logs and other cluster logs on Amazon S3, and to have them available after the cluster ends, you must specify an Amazon S3 bucket to receive these logs when you create the cluster. This is done using the --log-uri option. For more information on enabling logging for your cluster, see Configure Logging and Debugging (Optional).