[HIVE-15204] Hive-Hbase integration thorws "java.lang.ClassNotFoundException: NULL::character varying" (Postgres)

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.1.0
• Component/s: HBase Handler
• Labels: Postgres

Environment

apache-hive-2.1.0-bin
hbase-1.1.1

• Flags: Important
• Assignee: Unassigned
• Reporter: Anshuman
• Created: 15/Nov/16 07:27
• Updated: 16/Nov/16 06:47

Description

When doing hive to hbase integration, we have observed that current Apache Hive 2.x is not able to recognise 'NULL::character varying' (Variant data type of NULL in prostgres) properly and throws the java.lang.ClassNotFoundException exception.

Exception:
ERROR ql.Driver: FAILED: RuntimeException java.lang.ClassNotFoundException: NULL::character varying
java.lang.RuntimeException: java.lang.ClassNotFoundException: NULL::character varying
....
Caused by: java.lang.ClassNotFoundException: NULL::character varying
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)

Reason:

org.apache.hadoop.hive.ql.metadata.Table.java

final public Class<? extends InputFormat> getInputFormatClass() {
if (inputFormatClass == null) {
try {
String className = tTable.getSd().getInputFormat();

if (className == null) { /If the className is one of the postgres variant of NULL i.e. 'NULL::character varying' control is going to else block and throwing error./

if (getStorageHandler() == null)

{ return null; }

inputFormatClass = getStorageHandler().getInputFormatClass();
} else

{ inputFormatClass = (Class<? extends InputFormat>) Class.forName(className, true, Utilities.getSessionSpecifiedClassLoader()); }

} catch (ClassNotFoundException e)

{ throw new RuntimeException(e); }

}
return inputFormatClass;
}

Steps to reproduce:
Hive 2.x (e.g. apache-hive-2.1.0-bin) and HBase (e.g. hbase-1.1.1)

1. Install and configure Hive, if it is not already installed.
2. Install and configure HBase, if it is not already installed.
3. Configure the hive-site.xml File (as per recommended steps)
4. Provide necessary jars to Hive (as per recommended steps)
4. Create table in HBase as shown below -

create 'hivehbase', 'ratings'
put 'hivehbase', 'row1', 'ratings:userid', 'user1'
put 'hivehbase', 'row1', 'ratings:bookid', 'book1'
put 'hivehbase', 'row1', 'ratings:rating', '1'

put 'hivehbase', 'row2', 'ratings:userid', 'user2'
put 'hivehbase', 'row2', 'ratings:bookid', 'book1'
put 'hivehbase', 'row2', 'ratings:rating', '3'

put 'hivehbase', 'row3', 'ratings:userid', 'user2'
put 'hivehbase', 'row3', 'ratings:bookid', 'book2'
put 'hivehbase', 'row3', 'ratings:rating', '3'

put 'hivehbase', 'row4', 'ratings:userid', 'user2'
put 'hivehbase', 'row4', 'ratings:bookid', 'book4'
put 'hivehbase', 'row4', 'ratings:rating', '1'

5. Create external table as shown below
CREATE EXTERNAL TABLE hbasehive_table
(key string, userid string,bookid string,rating int)
STORED BY 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'
WITH SERDEPROPERTIES
("hbase.columns.mapping" = ":key,ratings:userid,ratings:bookid,ratings:rating")
TBLPROPERTIES ("hbase.table.name" = "hivehbase");

6. select * from hbasehive_table;
FAILED: RuntimeException java.lang.ClassNotFoundException: NULL::character varying

Issue Links

• is related to: HIVE-14322 Postgres db issues after Datanucleus 4.x upgrade