How to reduce the memory consumed by cassandra (so as to prevent crashes & OOMs) ?

[Aditya Gupta <ad...@gmail.com>]

I'm running a 4 nodes cassandra cluster of VMware ubuntu instances each
768MB memory (on a single machine for development purposes). I need to
reduce heap size appropriately as  my nodes have been crashing at times
with OOMs. How do I configure for this ? I think I would need to make some
tweaks with MAX_HEAP_SIZE & HEAP_NEWSIZE in cassandra-env.sh !? but I not
sure what should be the correct values I should put here for my case.

What would have been the values for these parameters in case I had just
512mb for each node?

Re: How to reduce the memory consumed by cassandra (so as to prevent crashes & OOMs) ?

[aaron morton <aa...@thelastpickle.com>]

MAX_HEAP_SIZE="500M"
HEAP_NEWSIZE="100M"

That is a very small amount of memory for java, you are probably going to have problems. Take a look at reducing these settings in cassandra.yaml to reduce the amount of memory used. 

memtable_total_space_in_mb
memtable_flush_queue_size
in_memory_compaction_limit_in_mb
concurrent_compactors 


You may also find this useful https://github.com/pcmanus/ccm

Cheers

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

On 28/02/2012, at 6:50 AM, Aditya Gupta wrote:

> I'm running a 4 nodes cassandra cluster of VMware ubuntu instances each 768MB memory (on a single machine for development purposes). I need to reduce heap size appropriately as  my nodes have been crashing at times with OOMs. How do I configure for this ? I think I would need to make some tweaks with MAX_HEAP_SIZE & HEAP_NEWSIZE in cassandra-env.sh !? but I not sure what should be the correct values I should put here for my case.
> 
> What would have been the values for these parameters in case I had just 512mb for each node?