In short the question is whether the row_cache_size_in_mb can exceed the heap setting for cassandra 1.1.4 if jna.jar is present in the libs? 
Yes. 
AFAIK jna.jar is not required for off heap row cache in 1.1.X

My heap settings are 8G and new heap size is 1600M. 
You can reduce the size of the heap in 1.1X. The default settings max out of 4G. 

Cheers

-----------------
Aaron Morton
Freelance Developer
@aaronmorton

On 4/10/2012, at 3:21 PM, Ananth Gundabattula <agundabattula@gmail.com> wrote:

Hello,

I have configured cassandra 1.1.4 to use row cache of 10GB ( the RAM on the machine is pretty big and hence the row cache size is high).  My heap settings are 8G and new heap size is 1600M. 

As I read from the forum and documentation, jna.jar allows to use non-heap memory for the row caches. 

The question I have is how is the configuration in cassandra.yaml for row_cache_size_in_mb interpreted? Is it referring to the non-heap setting or the memory used inside the heap to maintain book-keeping information about the non-heap memory ( as I gather from the postings that heap is indeed used to some extent while still using the non-heap memory for row caches). 

In short the question is whether the row_cache_size_in_mb can exceed the heap setting for cassandra 1.1.4 if jna.jar is present in the libs? 

Thanks for your time. 

Regards,
Ananth