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Posted to mapreduce-user@hadoop.apache.org by Radim Kolar <hs...@filez.com> on 2012/03/25 12:16:00 UTC

class usage counter in MapWritable

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?

Re: class usage counter in MapWritable

Posted by Brock Noland <br...@cloudera.com>.

Hi,

inline...

2012/3/25 Radim Kolar <hs...@filez.com>:
> 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:
http://wiki.apache.org/hadoop/HowToContribute

Cheers,
 Brock

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