2012/3/25 Radim Kolar <[EMAIL PROTECTED]>:
> current implementation of MapWritable and AbstractMapWritable do not track
> class usage. Class name is still serialized in write() to disk even if no
> instance of such class exists in stored table anymore.
> I propose to add usage tracking to AbstractMapWritable addToMap(Class
> clazz) and provide function removeFromMap which will be called by
> MapWritable. I can code such patch,. but i am inexperienced in hadoop
> development, What hadoop branch should i target?
I would first search to see if a JIRA
(https://issues.apache.org/jira/secure/Dashboard.jspa) has already
been raised and if not create one. Generally you want to target trunk
with your patch. Much more information here:
Apache MRUnit - Unit testing MapReduce - http://incubator.apache.org/mrunit/