Databases Reference
In-Depth Information
• There are other ways to get code, but these examples show use of Git.
• Install according to vendor instructions.
Our use of Gradle and Git implies that these commands will be downloading JARs,
checking code repos, etc., so you will need an Internet connection for most of the ex‐
amples in this topic.
Next, set up your command-line environment. You will need to have the following
environment variables set properly, according to the installation instructions for each
project and depending on your operating system:
•
JAVA_HOME
•
HADOOP_HOME
•
GRADLE_HOME
Assuming that the installers for both Java and Git have placed binaries in the appropriate
directories, now extend your
PATH
definition for the other tools that depend on Java:
$
export
PATH
=
$PATH
:
$HADOOP_HOME
/bin:
$GRADLE_HOME
/bin
OK, now for some tests. Try the following command lines to verify that your installations
worked:
$
java -version
$
hadoop -version
$
gradle --version
$
git --version
Each command should print its version information. If there are problems, most likely
you'll get errors at this stage. Don't worry if you see a warning like the following—that
is a known behavior in Apache Hadoop:
Warning:
$HADOOP_HOME
is deprecated.
the sample apps in this topic. However, it will help you follow project updates for the
example code, participate within the developer community, ask questions, etc.
Also note that you do not need to install Cascading. Certainly you can, but the Gradle
build scripts used in these examples will pull the appropriate version of Cascading from
the
Conjars Maven repo
automatically. Conjars has lots of interesting JARs for related
projects—take a peek sometime.
OK, now you are ready to download source code. Connect to a directory on your com‐
puter where you have a few gigabytes of available disk space, and then clone the whole
source code repo for this multipart series:
