Hive Insert - Failed with exception Unable to alter table. java.lang.NullPointerException - insert

Question

We are using Cloudera 5.6. We have configured Sentry for Hive. Whenever we issue an insert statment, it fails with the below exception. But when we check the table, the row is inserted properly. We have set all the permissions to hive.
$$$ insert into beckman values('rinku');
INFO : Number of reduce tasks is set to 0 since there's no reduce operator
INFO : number of splits:1
INFO : Submitting tokens for job: job_1459405260708_0002
INFO : The url to track the job: http://xxx.xxx.xxx.xxx:8088/proxy/application_1459405260708_0002/
INFO : Starting Job = job_1459405260708_0002, Tracking URL = http://xxx.xxx.xxx.xxx:8088/proxy/application_1459405260708_0002/
INFO : Kill Command = /opt/cloudera/parcels/CDH-5.6.0-1.cdh5.6.0.p0.45/lib/hadoop/bin/hadoop job -kill job_1459405260708_0002
INFO : Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0
INFO : 2016-03-31 23:20:31,401 Stage-1 map = 0%, reduce = 0%
INFO : 2016-03-31 23:20:37,788 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 1.4 sec
INFO : MapReduce Total cumulative CPU time: 1 seconds 400 msec
INFO : Ended Job = job_1459405260708_0002
INFO : Stage-4 is selected by condition resolver.
INFO : Stage-3 is filtered out by condition resolver.
INFO : Stage-5 is filtered out by condition resolver.
INFO : Moving data to: hdfs://ip-172-31-0-203.us-west-2.compute.internal:8020/user/hive2/warehouse/test.db/beckman/.hive-staging_hive_2016-03-31_23-20-23_107_7263355827488393299-2/-ext-10000 from hdfs://ip-172-31-0-203.us-west-2.compute.internal:8020/user/hive2/warehouse/test.db/beckman/.hive-staging_hive_2016-03-31_23-20-23_107_7263355827488393299-2/-ext-10002
INFO : Loading data to table test.beckman from hdfs://ip-172-31-0-203.us-west-2.compute.internal:8020/user/hive2/warehouse/test.db/beckman/.hive-staging_hive_2016-03-31_23-20-23_107_7263355827488393299-2/-ext-10000
ERROR : Failed with exception Unable to alter table. java.lang.NullPointerException
org.apache.hadoop.hive.ql.metadata.HiveException: Unable to alter table. java.lang.NullPointerException
at org.apache.hadoop.hive.ql.metadata.Hive.alterTable(Hive.java:533)
at org.apache.hadoop.hive.ql.metadata.Hive.alterTable(Hive.java:519)
at org.apache.hadoop.hive.ql.metadata.Hive.loadTable(Hive.java:1685)
at org.apache.hadoop.hive.ql.exec.MoveTask.execute(MoveTask.java:312)
at org.apache.hadoop.hive.ql.exec.Task.executeTask(Task.java:160)
at org.apache.hadoop.hive.ql.exec.TaskRunner.runSequential(TaskRunner.java:88)
at org.apache.hadoop.hive.ql.Driver.launchTask(Driver.java:1645)
at org.apache.hadoop.hive.ql.Driver.execute(Driver.java:1404)
at org.apache.hadoop.hive.ql.Driver.runInternal(Driver.java:1190)
at org.apache.hadoop.hive.ql.Driver.run(Driver.java:1055)
at org.apache.hadoop.hive.ql.Driver.run(Driver.java:1050)
at org.apache.hive.service.cli.operation.SQLOperation.runQuery(SQLOperation.java:143)
at org.apache.hive.service.cli.operation.SQLOperation.access$100(SQLOperation.java:69)
at org.apache.hive.service.cli.operation.SQLOperation$1$1.run(SQLOperation.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1707)
at org.apache.hive.service.cli.operation.SQLOperation$1.run(SQLOperation.java:207)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: MetaException(message:java.lang.NullPointerException)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$alter_table_with_cascade_result$alter_table_with_cascade_resultStandardScheme.read(ThriftHiveMetastore.java:42087)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$alter_table_with_cascade_result$alter_table_with_cascade_resultStandardScheme.read(ThriftHiveMetastore.java:42064)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$alter_table_with_cascade_result.read(ThriftHiveMetastore.java:42006)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Client.recv_alter_table_with_cascade(ThriftHiveMetastore.java:1402)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Client.alter_table_with_cascade(ThriftHiveMetastore.java:1386)
at org.apache.hadoop.hive.metastore.HiveMetaStoreClient.alter_table(HiveMetaStoreClient.java:340)
at org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient.alter_table(SessionHiveMetaStoreClient.java:296)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.invoke(RetryingMetaStoreClient.java:91)
at com.sun.proxy.$Proxy10.alter_table(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.hive.metastore.HiveMetaStoreClient$SynchronizedHandler.invoke(HiveMetaStoreClient.java:1998)
at com.sun.proxy.$Proxy10.alter_table(Unknown Source)
at org.apache.hadoop.hive.ql.metadata.Hive.alterTable(Hive.java:531)
... 22 more
Error: Error while processing statement: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.MoveTask (state=08S01,code=1)

Answer 1

I have noticed this issue when you try altering table with format/syntax along with database name. I.e something like : "<DATABASE>.<TABLENAME>".. Somehow this looks like an issue.
In order to overcome it, explicitly mention the database before you execute the actual query. A sample illustration :
use sampledb;
alter employeeTable .... ; // This works
vs
[Do not use the below]
alter sampledb.employeeTable.... // This doesn't work