Book Image

Cloudera Administration Handbook

By : Menon
Book Image

Cloudera Administration Handbook

By: Menon

Overview of this book

An easy-to-follow Apache Hadoop administrator’s guide filled with practical screenshots and explanations for each step and configuration. This book is great for administrators interested in setting up and managing a large Hadoop cluster. If you are an administrator, or want to be an administrator, and you are ready to build and maintain a production-level cluster running CDH5, then this book is for you.
Table of Contents (11 chapters)
10
Index

Understanding the secondary namenode UI

The secondary namenode is a checkpoint service for the namenode daemon that performs periodic merging of the edits log and the fsimage file. The secondary namenode UI can be accessed using the following URL:

http://<secondary-namenode-server>:50090/

The following screenshot shows the secondary namenode UI:

Understanding the secondary namenode UI

Just like the namenode UI, the secondary namenode UI also displays the Hadoop version. All checkpoint related information is available in this UI, which are given as follows:

  • Name Node Address: This is the RPC address of the primary namenode daemon. Secondary namenode uses this address to connect to primary namenode.
  • Start Time: This is the start timestamp of the secondary namenode service.
  • Last Checkpoint Time: This the timestamp of the last checkpoint action performed by the secondary namenode daemon.
  • Checkpoint Period: This property defines the schedule to perform the checkpoint. In the preceding screenshot, the value is 3,600 seconds. This...