[HIVE-2182] Avoid null pointer exception when executing UDF

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.5.0, 0.8.0
• Fix Version/s: 0.8.0
• Component/s: Query Processor

Environment

Hadoop 0.20.1, Hive0.8.0 and SUSE Linux Enterprise Server 10 SP2 (i586) - Kernel 2.6.16.60-0.21-smp (5)

• Hadoop Flags: Reviewed
• Assignee: Chinna Rao Lalam
• Reporter: Chinna Rao Lalam
• Created: 25/May/11 06:17
• Updated: 16/Dec/11 23:56
• Resolved: 14/Sep/11 17:13

Description

For using UDF's executed following steps

add jar /home/udf/udf.jar;
create temporary function grade as 'udf.Grade';
select m.userid,m.name,grade(m.maths,m.physics,m.chemistry) from marks m;

But from the above steps if we miss the first step (add jar) and execute remaining steps

create temporary function grade as 'udf.Grade';
select m.userid,m.name,grade(m.maths,m.physics,m.chemistry) from marks m;

In tasktracker it is throwing this exception

Caused by: java.lang.RuntimeException: Map operator initialization failed
		 at org.apache.hadoop.hive.ql.exec.ExecMapper.configure(ExecMapper.java:121)
		 ... 18 more
Caused by: java.lang.RuntimeException: java.lang.NullPointerException
		 at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:115)
		 at org.apache.hadoop.hive.ql.udf.generic.GenericUDFBridge.initialize(GenericUDFBridge.java:126)
		 at org.apache.hadoop.hive.ql.exec.ExprNodeGenericFuncEvaluator.initialize(ExprNodeGenericFuncEvaluator.java:133)
		 at org.apache.hadoop.hive.ql.exec.Operator.initEvaluators(Operator.java:878)
		 at org.apache.hadoop.hive.ql.exec.Operator.initEvaluatorsAndReturnStruct(Operator.java:904)
		 at org.apache.hadoop.hive.ql.exec.SelectOperator.initializeOp(SelectOperator.java:60)
		 at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:357)
		 at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:433)
		 at org.apache.hadoop.hive.ql.exec.Operator.initializeChildren(Operator.java:389)
		 at org.apache.hadoop.hive.ql.exec.TableScanOperator.initializeOp(TableScanOperator.java:133)
		 at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:357)
		 at org.apache.hadoop.hive.ql.exec.MapOperator.initializeOp(MapOperator.java:444)
		 at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:357)
		 at org.apache.hadoop.hive.ql.exec.ExecMapper.configure(ExecMapper.java:98)
		 ... 18 more
Caused by: java.lang.NullPointerException
		 at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:768)
		 at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:107)
		 ... 31 more

Instead of null pointer exception it should throw meaning full exception