[PIG-5387] Test failures on JRE 11

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.17.0
• Fix Version/s: 0.18.0
• Assignee: Nándor Kollár
• Reporter: Nándor Kollár
• Created: 08/May/19 14:11
• Updated: 21/May/19 11:53
• Resolved: 21/May/19 11:53

Description

I tried to compile Pig with JDK 8 and execute the test with Java 11, and faced with several test failures. For example TestCommit#testCheckin2 failed with the following exception:

2019-05-08 16:06:09,712 WARN  [Thread-108] mapred.LocalJobRunner (LocalJobRunner.java:run(590)) - job_local1000317333_0003
java.lang.Exception: java.io.IOException: Deserialization error: null
	at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:492)
	at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:552)
Caused by: java.io.IOException: Deserialization error: null
	at org.apache.pig.impl.util.ObjectSerializer.deserialize(ObjectSerializer.java:62)
	at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.setup(PigGenericMapBase.java:183)
	at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143)
	at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:799)
	at org.apache.hadoop.mapred.MapTask.run(MapTask.java:347)
	at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:271)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.NullPointerException
	at org.apache.pig.impl.plan.Operator.hashCode(Operator.java:106)
	at java.base/java.util.HashMap.hash(HashMap.java:339)
	at java.base/java.util.HashMap.readObject(HashMap.java:1461)
	at java.base/jdk.internal.reflect.GeneratedMethodAccessor12.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at java.base/java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1160)

It deserialization of one of the map plan failed, it appears we ran into JDK-8201131. I seems that the workaround in the issue report works, adding a readObject method to org.apache.pig.impl.plan.Operator:

    private void readObject(ObjectInputStream in) throws ClassNotFoundException, IOException {
        in.defaultReadObject();
    }

solves the problem, however I'm not sure that this is the optimal solution.