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Posted to user@cassandra.apache.org by Ian Danforth <id...@numenta.com> on 2011/08/16 03:08:07 UTC

Max heap not sticking?

All,

 When I connect to a node through jconsole it's telling me that my max heap
is only 1.7gb. (eg http://screencast.com/t/7DP8ovdUv) However I believe I
have properly specified that it should be 4GB in cassandra-env.sh. Total
memory is 7.5GB

 I see greatly increased GC activity as the heap approaches 1.7GB.

Can anyone suggest why the heap might not use all the memory as specified?

Ian


>From cassandra-env.sh

MAX_HEAP_SIZE="4096M"
HEAP_NEWSIZE="400M"

JVM_OPTS="$JVM_OPTS -Xms${MAX_HEAP_SIZE}"
JVM_OPTS="$JVM_OPTS -Xmx${MAX_HEAP_SIZE}"
JVM_OPTS="$JVM_OPTS -Xmn${HEAP_NEWSIZE}"

Re: Max heap not sticking?

Posted by aaron morton <aa...@thelastpickle.com>.

Ian did you sort this out ? 

What values do you see passed in when you run ps aux | grep cassandra ? 

Cheers

-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com

On 16/08/2011, at 1:08 PM, Ian Danforth wrote:

> All,
> 
>  When I connect to a node through jconsole it's telling me that my max heap is only 1.7gb. (eg http://screencast.com/t/7DP8ovdUv) However I believe I have properly specified that it should be 4GB in cassandra-env.sh. Total memory is 7.5GB
> 
>  I see greatly increased GC activity as the heap approaches 1.7GB. 
> 
> Can anyone suggest why the heap might not use all the memory as specified? 
> 
> Ian
>  
> 
> From cassandra-env.sh
> 
> MAX_HEAP_SIZE="4096M"
> HEAP_NEWSIZE="400M"
> 
> JVM_OPTS="$JVM_OPTS -Xms${MAX_HEAP_SIZE}"
> JVM_OPTS="$JVM_OPTS -Xmx${MAX_HEAP_SIZE}"
> JVM_OPTS="$JVM_OPTS -Xmn${HEAP_NEWSIZE}"
>