The goal is to expand on our Word Count example in Cascading, and show how to write a custom Operation.
We'll keep building on this example until we have a MapReduce implementation of TF-IDF.
More detailed background information and step-by-step documentation is provided at https://github.com/cascading/impatient/wiki
To generate an IntelliJ project use:
To build the sample app from the command line use:
gradle clean jar
Before running this sample app, be sure to set your
HADOOP_HOME environment variable. Then clear the
output directory, then to run on a desktop/laptop with Apache Hadoop in standalone mode:
rm -rf output hadoop jar ./build/libs/impatient.jar data/rain.txt output/wc
To view the results:
To run the Pig version of the script, make sure
PIG_HOME is set and run :
rm -rf output mkdir -p dot pig -p docPath=./data/rain.txt -p wcPath=./output/wc ./src/scripts/wc.pig
An example of log captured from a successful build+run is at https://gist.github.com/3021655
For more discussion, see the cascading-user email forum.
Stay tuned for the next installments of our Cascading for the Impatient series.