Moving the question to Apache Avro's user@ lists. Please use the right lists for the most relevant answers.
Avro is a different serialization technique that intends to replace the Writable serialization defaults in Hadoop. MR accepts a list of serializers it can use for its key/value structures and isn't limited to Writable in any way. Look up the property "io.serializations" in your Hadoop's core-default.xml for more information. The Avro project also offers fast comparator classes that are used for comparing the bytes/structures of Avro objects. This is mostly auto-set for you when you use the MR framework as described at http://avro.apache.org/docs/current/api/java/org/apache/avro/mapred/package-summary.html (via AvroJob helper class). On Tue, Apr 30, 2013 at 6:51 PM, Rahul Bhattacharjee <[email protected]> wrote: > Hi, > > When dealing with Avro data files in MR jobs ,we use AvroMapper , I noticed > that the output of K and V of AvroMapper isnt writable and neither the key > is comparable (these are AvroKey and AvroValue). As the general > serialization mechanism is writable , how is the K,V pairs in case of avro , > travel across nodes? > > Thanks, > Rahul -- Harsh J
