Open Stack

Hi ops and dev-folks,

We over at godaddy (running rabbitmq with openstack) have been hitting a 
issue that has been causing the `rabbit_mgmt_db` consuming nearly all 
the processes memory (after a given amount of time),

We've been thinking that this bug (or bugs?) may have existed for a 
while and our dual-version-path (where we upgrade the control plane and 
then slowly/eventually upgrade the compute nodes to the same version) 
has somehow triggered this memory leaking bug/issue since it has 
happened most prominently on our cloud which was running nova-compute at 
kilo and the other services at liberty (thus using the versioned objects 
code path more frequently due to needing translations of objects).

The rabbit we are running is 3.4.0 on CentOS Linux release 7.2.1511 with 
kernel 3.10.0-327.4.4.el7.x86_64 (do note that upgrading to 3.6.2 seems 
to make the issue go away),

# rpm -qa | grep rabbit

rabbitmq-server-3.4.0-1.noarch

The logs that seem relevant:

```
**********************************************************
*** Publishers will be blocked until this alarm clears ***
**********************************************************

=INFO REPORT==== 1-Jul-2016::16:37:46 ===
accepting AMQP connection <0.23638.342> (127.0.0.1:51932 -> 127.0.0.1:5671)

=INFO REPORT==== 1-Jul-2016::16:37:47 ===
vm_memory_high_watermark clear. Memory used:29910180640 allowed:47126781542
```

This happens quite often, the crashes have been affecting our cloud over 
the weekend (which made some dev/ops not so happy especially due to the 
july 4th mini-vacation),

Looking to see if anyone else has seen anything similar?

For those interested this is the upstream bug/mail that I'm also seeing 
about getting confirmation from the upstream users/devs (which also has 
erlang crash dumps attached/linked),

https://groups.google.com/forum/#!topic/rabbitmq-users/FeBK7iXUcLg

Thanks,

-Josh