Apache-Open-Source-Project

Option to print MR/Tez plan before launching [PIG-5210]

An Improvement for Apache Open Source Software Pig

Why do we add this patch?

For pig script, users need to use pig -e explain -script test.pigto print out MR/Tez Plan. But for Python script, it is a hard thing for PIG to explain the plan automatically. This option can help to print out MR/Tez plan automatically before implementing MapReduce.

Steps to creat a Jira issue and upload the patch

• Get clone of 0.17.0 version PIG by git pull 
• Set up Eclipse ant build.xml
• Import Pig src to Eclipse, and set pig.print.exec.plan "true" in file JobControlCompiler.java,TezJobCompiler.java before Mapreduce starts

// Set pig.print.exec.plan "true" in mapReduce engine
if (conf.getBoolean(PigConfiguration.PIG_PRINT_EXEC_PLAN, false)) {  log.info(mro.toString()); }

// Set pig.print.exec.plan "true" in Tez engine
if (conf.getBoolean(PigConfiguration.PIG_PRINT_EXEC_PLAN, false)) { log.info(tezPlanNode.getTezOperPlan()); }

• Check for compiling ant
• Start remote debugger in Eclipse

export PIG_OPTS="- agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=8000" 

• Or start to run pig only in terminal

unset PIG_OPTS

• Test for MR engine -x local test.pig; Test for Tez engine -x tez_local test.pig
• MapReduce plan printed as expected for MR/Tez engine

• Upload Patch to Jira