[MAPREDUCE-2225] MultipleOutputs should not require the use of 'Writable'

• Type: Improvement
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.20.1
• Fix Version/s: 0.23.0
• Component/s: job submission

Environment

Linux

• Hadoop Flags: Reviewed
• Release Note: MultipleOutputs should not require the use/check of 'Writable' interfaces in key and value classes.
• Tags: multipleoutputs, writable, serialization
• Assignee: Harsh J
• Reporter: Harsh J
• Created: 19/Dec/10 17:07
• Updated: 15/Nov/11 00:48
• Resolved: 02/Mar/11 05:32

Description

MultipleOutputs right now requires for Key/Value classes to utilize the Writable and WritableComparable interfaces, and fails if the associated key/value classes aren't doing so.

With support for alternates like Avro serialization, using Writables isn't necessary and thus the MO class must not strictly check for them.

And since comparators may be given separately, key class doesn't need to be checked for implementing a comparable (although it is good design if the key class does implement Comparable at least).

Am not sure if this brings about an incompatible change (does Java have BIC? No idea).