Databases Reference
In-Depth Information
Though the usefulness of these tools may not be immediately apparent at this stage,
they'll come in handy as you begin to perform more sophisticated tasks on your
cluster. You'll realize their importance as we study Hadoop more in depth.
2.5
Summary
In this chapter we've discussed the key nodes and the roles they play within the
Hadoop architecture. You've learned how to configure your cluster, as well as manage
some basic tools to monitor your cluster's overall health.
Overall, this chapter focuses on one-time tasks. Once you've formatted the
NameNode for your cluster, you'll (hopefully) never need to do so again. Likewise,
you shouldn't keep altering the hadoop-site.xml configuration file for your cluster
or assigning daemons to nodes. In the next chapter, you'll learn about the aspects of
Hadoop you'll be interacting with on a daily basis, such as managing files in HDFS.
With this knowledge you'll be able to begin writing your own MapReduce applications
and realize the true potential that Hadoop has to offer.
