Question

I am new to pig script, Hadoop, Hbase. Here’s what i need to know. I wanted to run a pig script, I don’t want to embed the pig script in my java program and wanted to run it through any Pig Execution methods passing the necessary pig script and parameters (possibly parameter file). Does the core pig library or any other library provides that way to execute a pig script. I already tried with java run-time exec method, I pass some parameters with space separated strings so i dropped calling pig grunt command through run-time exec method since it is not the proper way to execute pig commands.

Answer 1

You can use org.apache.pig.PigServer to run pig scripts from Java programs.

PigServer pigServer = new PigServer(ExecType.MAPREDUCE);
pigServer.registerScript("scripts/test.pig");

Requires ‘pig.properties’ on classpath.

fs.default.name=hdfs://<namenode-hostname>:<port>
mapred.job.tracker=<jobtracker-hostname>:<port>

Or pass an instance of java.util.Properties to PigServer constructor.

Properties props = new Properties();
props.setProperty("fs.default.name", "hdfs://<namenode-hostname>:<port>");
props.setProperty("mapred.job.tracker", "<jobtracker-hostname>:<port>");
PigServer pigServer = new PigServer(ExecType.MAPREDUCE, props);