Impala Administration and Performance Improvements - Learning Cloudera Impala - page 109

Chapter 5. Impala Administration and

Performance Improvements

After going through all the examples in the previous chapter, I am sure you are able
to process data through Impala queries. Now you will have questions about how to
improve query performance, and this is one of the two key objectives of this chapter.
The other objective is to show effective management of our Impala cluster that will
keep it up and running.

In this chapter, we will cover two important topics: Impala administration and perform-
ance improvements. Within the Impala administration section, I will show you how you
can administer Impala using Cloudera Manager. After that, using debug web server,
I will teach you to verify Impala-specific information for its correctness. We will see
Impala logs and daemons using the statestore UI. The next part of the Impala admin
is about Impala High Availability. We will learn key traits of how to keep Impala going
in the event of a problem.

In the Improving performance section, we will cover various ways to improve and tune
query performance. We will learn to test Impala queries to understand if they are per-
forming well or not and, if not, what you can do to improve their performance—either
fine-tune the cluster or modify the query statement or its execution. Finally, let's start
with Impala administration.

Impala administration

We have already discussed in previous chapters that you can install and run Impala
with or without Cloudera Manager; however, for simplicity, it is good to have Cloudera
Manager manage your Impala cluster. This will help you spend your crucial time work-
ing with data transformation rather than cluster administration. In this chapter, I will
assume that you are managing your Impala cluster using Cloudera Manager and
provide more information based on that assumption.

Administration with Cloudera Manager

While describing Cloudera Manager in detail is beyond the scope of this topic, I will
try to provide some guidance to you so you can use Cloudera Manager to administer