Category Archives: HDFS

Multi-host SecondaryNameNode Configuration

Categories: Hadoop HDFS

You might think that the SecondaryNameNode is a hot backup daemon for the NameNode. You’d be wrong. The SecondaryNameNode is a poorly understood component of the HDFS architecture, but one which provides the important function of lowering NameNode restart time. This blog post describes how to configure this daemon in a large-scale environment. The default Hadoop configuration places an instance of the SecondaryNameNode on the same node as the NameNode. A more scalable configuration involves configuring the SecondaryNameNode on a different machine.

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