| Subject: | Defect |
| Date: | Tue, 14 Jul 2015 01:35:49 -0400 |
| To: | bug-DBD-JDBC [...] rt.cpan.org |
| From: | mat bentley <mathewkbentley [...] gmail.com> |
Description:
DBD-JDBC throws an exception when connecting to a HiveQL service in any
Hadoop distribution. This is due to Apache's decision to throw exceptions
from the DatabaseMetaData implementation in their driver for the method
"supportsGetGeneratedKeys()" instead of returning false. Ideally this would
be fixed in Apache's Hive drivers, however that isn't an option for those
using DBD with a commercial distribution of Apache's Hive Drivers where
source code is not available (in violation of the GPL, talking about IBM's
BigInsights specifically).
Desired behavior:
I can load hive-jdbc jar and connect to hive through DBD without errors.
Actual behavior:
I can load hive-jdbc and start a dbd service, however when connecting an
exception is thrown and DBD effectively dies:
com.vizdom.dbd.jdbc.Connection - Error
java.sql.SQLException: Method not supported
at
org.apache.hive.jdbc.HiveDatabaseMetaData.supportsGetGeneratedKeys(HiveDatabaseMetaData.java:931)
at com.vizdom.dbd.jdbc.Connection.handleRequest(Connection.java:425)
at com.vizdom.dbd.jdbc.Connection.run(Connection.java:211)
at java.lang.Thread.run(Thread.java:636)
Solution:
catch SQLException when calling supportsGetGeneratedKeys on
DatabaseMetaData instance within the com.vizdom.dbd.jdbc.Connection class.
Changed:
mSupportsGetGeneratedKeys = dbmd.supportsGetGeneratedKeys();
to:
try{
mSupportsGetGeneratedKeys = dbmd.supportsGetGeneratedKeys();
}catch(SQLException x){
gLog.debug("Driver threw exception checking if generated keys are
supported. (\"DatabaseMetaData.supportsGetGeneratedKeys()\")", x);
}
mSupportsGetGeneratedKeys is a boolean primitive which defaults to false,
if the invocation causes an exception to throw, that can be inferred as
false without a negative impact to application behavior.
This impacts at least 0,71 of DBD.
Cheers,
Mat