Hi Du,
I don't think NullWritable has ever been serializable, so you must be doing
something differently from your previous program. In this case though, just use
a map() to turn your Writables to serializable types (e.g. null and String).
Matie
On September 12, 2014 at 8:48:36 PM, Du Li (l...@yahoo-inc.com.invalid) wrote:
Hi,
I was trying the following on spark-shell (built with apache master and hadoop
2.4.0). Both calling rdd2.collect and calling rdd3.collect threw
java.io.NotSerializableException: org.apache.hadoop.io.NullWritable.
I got the same problem in similar code of my app which uses the newly released
Spark 1.1.0 under hadoop 2.4.0. Previously it worked fine with spark 1.0.2
under either hadoop 2.40 and 0.23.10.
Anybody knows what caused the problem?
Thanks,
Du
----
import org.apache.hadoop.io.{NullWritable, Text}
val rdd = sc.textFile("README.md")
val res = rdd.map(x => (NullWritable.get(), new Text(x)))
res.saveAsSequenceFile("./test_data")
val rdd2 = sc.sequenceFile("./test_data", classOf[NullWritable], classOf[Text])
rdd2.collect
val rdd3 = sc.sequenceFile[NullWritable,Text]("./test_data")
rdd3.collect
