Hi, I'm currently working on a simple Cassandra Loader that reads an index and then works on that data. Now whenever I try to work on the retrieved data I get a strange error:
java.io.IOException: Type mismatch in key from map: expected > org.apache.pig.impl.io.NullableBytesWritable, recieved > org.apache.pig.impl.io.NullableText > at > org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:845) > at > org.apache.hadoop.mapred.MapTask$NewOutputCollector.write(MapTask.java:541) > at > org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80) > at > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce$Map.collect(PigMapReduce.java:115) > at > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapBase.runPipeline(PigMapBase.java:234) > at > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapBase.map(PigMapBase.java:227) > at > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapBase.map(PigMapBase.java:52) > at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144) > at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:621) > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:305) > at > org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:177) > The script is pretty simple right now: rows = LOAD 'cassandra://localhost:9160/...' USING CassandraIndexReader() as > (col1, col2, col3); > dump rows; > grouped = GROUP rows BY col1; > dump grouped; > The first dump works fine,while the second just dies with the above error. Strangely when I store it on disc and then load it with PigStorage() again it just works as expected. Am I doing something wrong with my Custom Loader? Regards, Chris
