Hi, all
I wrote a spark program which uses the Kryo serialization. When I count a rdd which type is RDD[(String,String)], it reported an Exception like the following : * Class is not registered: org.apache.spark.util.collection.CompactBuffer[] * Note: To register this class use: kryo.register(org.apache.spark.util.collection.CompactBuffer[].class); I found that CompactBuffer is a private class that I could not use the API sparkConf.registerKryoClasses to register it. Although I found a solution from Andras Barjak that is using the statement : kryo.register(ClassTag(Class.forName("org.apache.spark.util.collection.CompactBuffer")).wrap.runtimeClass), I tried it with sparkConfg.registerKryoClasses, and only got another Exception : * Class is not registered: scala.reflect.ManifestFactory$$anon$1 Could anybody tell me : 1.Why should I register CompactBuffer[] ? My program never used it. 2.How to solve this problem? Many Thanks!