[PIG-5160] SchemaTupleFrontend.java is not thread safe, cause PigServer thrown NPE in multithread env

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.17.0
• Labels: patch
• Patch Info: Patch Available
• Flags: Patch
• Assignee: Anyi Li
• Reporter: Anyi Li
• Created: 28/Feb/17 20:37
• Updated: 03/Mar/17 15:57

Description

Calling PigServer in multi-thread environment will randomly throw NPE at

Caused by: org.apache.pig.backend.executionengine.ExecException: ERROR 0: java.lang.NullPointerException
    at org.apache.pig.backend.hadoop.executionengine.HExecutionEngine.launchPig(HExecutionEngine.java:310)
    at org.apache.pig.PigServer.launchPlan(PigServer.java:1390)
    at org.apache.pig.PigServer.executeCompiledLogicalPlan(PigServer.java:1375)
    at org.apache.pig.PigServer.storeEx(PigServer.java:1034)
    ... 6 more
Caused by: java.lang.NullPointerException
    at org.apache.pig.data.SchemaTupleFrontend.registerToGenerateIfPossible(SchemaTupleFrontend.java:255)
    at org.apache.pig.newplan.logical.relational.LogToPhyTranslationVisitor.visit(LogToPhyTranslationVisitor.java:876)
    at org.apache.pig.newplan.logical.relational.LOForEach.accept(LOForEach.java:87)
    at org.apache.pig.newplan.DependencyOrderWalker.walk(DependencyOrderWalker.java:75)
    at org.apache.pig.newplan.PlanVisitor.visit(PlanVisitor.java:52)
    at org.apache.pig.backend.hadoop.executionengine.HExecutionEngine.compile(HExecutionEngine.java:260)
    at org.apache.pig.backend.hadoop.executionengine.HExecutionEngine.launchPig(HExecutionEngine.java:295)
    ... 9 more

because SchemaTupleFrontend.java has lots of static methods which refer to static variables. Need a patch to create threadlocal variables to make it thread safe