[rabbitmq-discuss] Memory High Watermark.

[Duncan McIntyre]

Because of this:

The default memory threshold is set to 40% of installed RAM. Note that this
does not prevent the RabbitMQ server from using more than 40%, it is merely
the point at which publishers are throttled. Erlang's garbage collector
can, in the worst case, cause double the amount of memory to be used (by
default, 80% of RAM). It is strongly recommended that OS swap or page files
are enabled.