Databases Reference
In-Depth Information
Remote Mode
In
Remote Mode
, we submit our topology to the Storm cluster, which is composed of
many processes, usually running on different machines. Remote Mode doesn't show
debugging information, which is why it's considered
Production Mode
. However, it is
possible to create a Storm cluster on a single development machine, and it's a good idea
to do so before deploying to production, to make sure there won't be any problems
running the topology in a production environment.
You'll learn more about Remote Mode in
Chapter 6
, and I'll show how to install a
cluster in
Appendix B
.
Hello World Storm
For this project, we'll create a simple topology to count words. We can consider this
the “Hello World” of Storm topologies. However, it's a very powerful topology because
it can scale to virtually infinite size, and with some small modifications we could even
use it to create a statistical system. For example, we could modify the project to find
trending topics on Twitter.
To create the topology, we'll use a spout that will be responsible for reading words, a
first bolt to normalize words, and a second bolt to count words, as we can see in
Figure 2-1
.
Figure 2-1. Getting started topology
You can download the source code of the example as a ZIP file at
https://github.com/
If you use
git
(a distributed revision control and source code manage-
ment), you can run
git clone
git@github.com
:
storm-book/examples-
ch02-getting_started.git
into the directory where you want to down-
load the source code.
