Tuning Namenode

In this recipe, we will look at tuning Namenode by making some important configuration changes. Namenode is more CPU and memory bound and must run on hardware with multi-core CPU and large memory to accommodate the entire namespace.

We will look at parameters only for the Namenode, which in production will come into effect in conjunction with HDFS and Datanode parameters, discussed in this chapter.

Getting ready

To complete the recipe, the user must have a running cluster with HDFS and YARN setup. Users can refer to Chapter 1, Hadoop Architecture and Deployment, for installation details.

The assumption here is that the user is well familiar with Namenode functionality and can edit and restart services for changes to be effective.

Note

It is recommended that users explore the load characteristics of Namenode and understand its memory usage, thread count, and GC cycle.

How to do it...

1. Connect to the master node master1.cyrus.com and switch to the hadoop user.

   The first thing to make...