[rabbitmq-discuss] rabbitmq-server dies from out of memory

Thu Oct 31 17:07:57 GMT 2013

On 31/10/13 15:24, François Beausoleil wrote:
> I changed overcommit_memory from 2 to 0, and RabbitMQ stays up for
> more than 15 seconds now. That seems to have been my error.

Ah, thanks for getting back to us.

I have to admit to being ignorant of Linux overcommit settings. Reading
the man page I see that /proc/sys/vm/overcommit_memory is described thus:

> In mode 2 (available since Linux 2.6), the total virtual address
> space on the system is limited to (SS + RAM*(r/100)), where SS is the
> size of the swap space, and RAM is the size of the physical memory,
> and r is the contents of the file /proc/sys/vm/overcommit_ratio.

So with your settings:

# cat /proc/sys/vm/overcommit_ratio
50
# cat /proc/sys/vm/overcommit_memory
2

it sounds like the kernel would refuse to use more than (16GB + swap) of 
memory. What was the swap space if you don't mind me asking?

Unfortunately I don't know if RabbitMQ can detect a situation like this, 
so it's very possible it went over the kernel's limit while still being 
within 32GB...

Cheers, Simon

-- 
Simon MacMullen
RabbitMQ, Pivotal