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From "Giridhar Addepalli" <giridhar.addepa...@komli.com>
Subject DBOutputFormat with one reducer
Date Wed, 25 May 2011 20:57:43 GMT
Hi,

 

We have MapReduce program which writes data to mysql database using
DBOutputFormat.

Our program has one reducer.

I understand that all the inserts happen during the close() operation of
the reducer.

Is it gauranteed that this operation is atomic ? i.e; what happens if
the writes fail in the middle of the operation.

Does it mean that only partial number of rows get in to mysql database?

 

What does it take to make the write operation atomic ?

 

Any suggestions around our situation( alternative solutions ) are
welcome.

 

Thanks,

Giridhar.


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