Casey,
It sounds like the JVM is behaving. Perhaps turn off mmapped
disk_access to double check that the number you are seeing as resident does not
include the mapped memory?
Aaron
On 10/03/2011, at 6:36 AM, Jonathan Ellis wrote:
> I edited Peter Schuller's reply last time this came up into a FAQ:
> http://wiki.apache.org/cassandra/FAQ#mmap
>
> On Wed, Mar 9, 2011 at 11:10 AM, Casey Deccio <ca...@deccio.net> wrote:
>> On Sat, Mar 5, 2011 at 7:37 PM, aaron morton <aa...@thelastpickle.com>
>> wrote:
>>>
>>> There is some additional memory usage in the JVM beyond that Heap size, in
>>> the permanent generation. 900mb sounds like too much for that, but you can
>>> check by connecting with JConsole and looking at the memory tab. You can
>>> also check the heap size there to see that it's under the value you've set.
>>
>> Thanks for the tip!
>>
>> From JConsole:
>> Heap memory usage: Current 46M; Max 902M
>> Non-Heap memory usage: Current 34M; Max 200MB
>>
>> Both of these seem reasonable and don't reach the (current) 2.1 GB resident
>> usage I am seeing.
>>
>>> Check you are using standard disk access (in conf/cassandra.yaml) rather
>>> than memory mapped access. However the memory mapped memory is reported as
>>> virtual memory, not resident. So I'm just mentioning it to be complete.
>>
>> At the moment, it's set to "auto", but it's a 64-bit machine, so I believe
>> it's using memory mapped. The virtual memory usage says that it is 54.6 GB.
>>
>>> If you think you've configured things correctly and the JVM is not
>>> behaving (which is unlikely) please include some information on the JVM and
>>> OS versions and some hard numbers about what the process is using.
>>
>> Debian 6.0 using openjdk-6-jre-lib-6b18-1.8.3-2+squeeze1
>>
>> Thanks for your help.
>>
>> Casey
>>
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com
