[rabbitmq-discuss] Some bugs in management plugin and HA

Thu Jul 12 14:32:39 BST 2012

Hi Michał,
At Tue, 10 Jul 2012 15:29:55 +0200,
Michał Kiędyś wrote:
> I found some bugs in management plugin and HA:
> 
> Configuration:
> Cluster with 4 nodes:
> arch-task-mq-1 (disk), arch-task-mq-2 (ram), arch-task-mq-3 (disk), arch-task-mq-4 (ram)
> Version 2.8.4
> Erlang R14A
> 
> 1.
> On node arch-task-mq-3 I execute iptables commands:
> 
> iptables -A INPUT -s arch-task-mq-1 -j DROP
> iptables -A OUTPUT -p tcp -d arch-task-mq-1 -j DROP
> [...]

What you're doing here is simulating a netsplit with iptables. RabbitMQ clusters
(or in other words, mnesia clusters) are not tolerant to that, as we state
clearly: http://www.rabbitmq.com/clustering.html . The behaviour if that happens
is pretty much undefined but it'll definitely lead to bad things. If you are
expecting netsplits, use federation or shovel.

--
Francesco * Often in error, never in doubt