Question & Answer
Question
In IBM InfoSphere BigInsights can I have a DataNode on the same machine as the NameNode?
Answer
Yes, you can have a DataNode on the same machine as the NameNode. However, it is recommended only when you have a small cluster (a few machines, for example, fewer than 10). When using the HDFS, the name node keeps track of all the data in the Hadoop file system. Because this data is kept in memory, when you also have a DataNode on the NameNode, you run a greater risk of running out of memory on the NameNode machine, and thus crashing your BigInsights environment.
When you have a limited amount of data and very few DataNodes, the risk is not very large.
Here is a recommended setup from the Hadoop setup guide.
- Typically one machine in the cluster is designated as the NameNode and another machine the as JobTracker, exclusively. These are the masters. The rest of the machines in the cluster act as both DataNode and TaskTracker. These are the slaves.
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Document Information
Modified date:
18 July 2020
UID
swg21567753