It seems to be coming from the region server side... so one thing you can check is the region server logs and see if the NPEs are there. If not, and there's nothing suspicious, then consider enabling DEBUG for hbase and re-run the job to hopefully get more information.
J-D On Wed, Jan 26, 2011 at 8:44 AM, Venkatesh <[email protected]> wrote: > > > > Using 0.20.6..any solutions? Occurs during mapper phase..will increasing > retry count fix this? > thanks > > here's the stack trace > > org.apache.hadoop.hbase.client.RetriesExhaustedException: Trying to contact > region server null for region , row '', but failed after 10 attempts. > > Exceptions: > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > java.lang.NullPointerException > > > > at > org.apache.hadoop.hbase.client.HConnectionManager$TableServers.getRegionServerWithRetries(HConnectionManager.java:1045) > > at > org.apache.hadoop.hbase.client.HTable$ClientScanner.nextScanner(HTable.java:2003) > > at > org.apache.hadoop.hbase.client.HTable$ClientScanner.initialize(HTable.java:1923) > > at org.apache.hadoop.hbase.client.HTable.getScanner(HTable.java:403) > > at > org.apache.hadoop.hbase.mapreduce.TableInputFormatBase$TableRecordReader.restart(TableInputFormatBase.java:110) > > at > org.apache.hadoop.hbase.mapreduce.TableInputFormatBase$TableRecordReader.nextKeyValue(TableInputFormatBase.java:210) > > at > org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.nextKeyValue(MapTask.java:423) > > at org.apache.hadoop.mapreduce.MapContext.nextKeyValue(MapContext.java:67) > > at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143) > > at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:621) > > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:305) > > at org.apache.hadoop.mapred.Child.main(Child.java:170) > >
