>> java.lang.IncompatibleClassChangeError: Found class org.apache.hadoop.mapreduce.TaskAttemptContext, but interface was expected
This error is about binary incompatibility between Hadoop 1 and 2. I suspect that the following jar that you register is the culprit- >> REGISTER mongo-hadoop-pig-1.2.1-SNAPSHOT-hadoop_2.4.jar This conflicts with Hadoop 1.0.3 that you're using. On Wed, Jul 16, 2014 at 7:48 AM, Sharon Rapoport <sha...@plaid.com> wrote: > Hello, > > I am trying to store an alias into mongo and getting an error. > > Example script: > > REGISTER mongo-hadoop-pig-1.2.1-SNAPSHOT-hadoop_2.4.jar > REGISTER mongo-2.4.jar > > categories_raw = LOAD > 'mongodb://username:password@mydb...:27017/db.categories?authSource=admin' > USING com.mongodb.hadoop.pig.MongoLoader(); > > doing a dump the load went fine, I indeed have my data. > Now just trying to dump it back: > > store categories_raw into > 'mongodb://username:password@mydb...:27017/db.categories_pig?authSource=admin' > USING com.mongodb.hadoop.pig.MongoInsertStorage(); > > I get this error: > FATAL org.apache.hadoop.mapred.Child (main): Error running child : > java.lang.IncompatibleClassChangeError: Found class > org.apache.hadoop.mapreduce.TaskAttemptContext, but interface was expected > at > com.mongodb.hadoop.MongoOutputFormat.getRecordWriter(MongoOutputFormat.java:48) > at > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigOutputFormat.getRecordWriter(PigOutputFormat.java:84) > at > org.apache.hadoop.mapred.MapTask$NewDirectOutputCollector.<init>(MapTask.java:635) > at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:760) > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:375) > at org.apache.hadoop.mapred.Child$4.run(Child.java:255) > at java.security.AccessController.doPrivileged(Native Method) > at javax.security.auth.Subject.doAs(Subject.java:415) > at > org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1132) > at org.apache.hadoop.mapred.Child.main(Child.java:249) > I am using EMR with > Pig 0.11.1.1 > AMI version 2.4.2, Hadoop 1.0.3 > > I am somewhat new to pig… Switched after I’ve had enough of Hive bugs, but > starting to regret that ;) > > Any help is appreciated! > > Sharon > >
