Hadoop DFS (HDFS) bindings for Ruby
This library provides native C bindings to Hadoop's libhdfs, for interacting with Hadoop DFS.
You will need:
Java JDK and JRE (yes, both). The build file will attempt to find it for you.
Hadoop's libhdfs. On Ubuntu/Debian you will need libhdfs0 and libhdfs0-dev.
Hadoop Core and DFS libraries.
Install from gems. Note that you will need to provide JAVA_HOME so the compiler can find the required libraries.
The installation will attempt to discover the location of the libaries, but if it fails, you can try setting the environment variable JAVA_LIB to the library path of the JDK/JRE.
Installing with a specific Java JDK:
sudo env JAVA_HOME=/usr/lib/jvm/java-6-openjdk gem install ruby-hdfs
The library also depends on an installation of Hadoop DFS. The Cloudera distribution of Hadoop is pretty good:
Sample classpath setup (yes, welcome to JAR hell):
export CLASSPATH=$CLASSPATH:/usr/lib/hadoop/hadoop-0.18.3-6cloudera0.3.0-core.jar for jarfile in /usr/lib/hadoop/lib/*.jar; do export CLASSPATH=$CLASSPATH:$jarfile done
Wait, there's more. You will also need libjvm.so in your library path, which comes with the JRE. This might work:
Not all APIs have been implemented yet.
libhdfs will sometimes throw exceptions, which will be output instead of caught by Ruby. This is annoying but harmless.
Building from source
To build from source:
On completion, the compiled extension will be available in ext/hdfs.
Copyright © 2010 Alexander Staubo. See LICENSE for details.