MR-Job: Exception in DBOutputFormat

[Steinmaurer Thomas <Th...@scch.at>]

Hello,

 

I'm writing a MR-Job to write HBase data to Oracle. The mapper works,
but the reducer produces the following exception:

 

java.io.IOException

        at
org.apache.hadoop.mapreduce.lib.db.DBOutputFormat.getRecordWriter(DBOutp
utFormat.java:180)

        at
org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:559)

        at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:414)

        at org.apache.hadoop.mapred.Child$4.run(Child.java:270)

        at java.security.AccessController.doPrivileged(Native Method)

        at javax.security.auth.Subject.doAs(Subject.java:396)

        at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformatio
n.java:1127)

        at org.apache.hadoop.mapred.Child.main(Child.java:264)

 

 

I'm doing the JDBC plumbing like that:

 

        DBConfiguration.configureDB(

            conf

            , "oracle.jdbc.driver.OracleDriver"

            , "jdbc:oracle:thin:@//xxx.com:1521/SID "

            , "user"

            , "pwd"

        );

        String[] fields = {"HBASE_KEY", "VALUE_COUNT", "VALUE_SUM",
"VALUE_AVG", "VALUE_MIN", "VALUE_MAX"}; 

        DBOutputFormat.setOutput(

            job

            , "HBASE_AGGREGATES"

            , fields

        );

 

So I think, basically this is right. I've also copied ojdbc6.jar into
the hadoop lib/ directory.

 

Any ideas on what might be wrong?

 

Thanks,

Thomas