[rabbitmq-discuss] 2.7.1 mirrored queues leak a lot of memory on slave nodes

[Reverend Chip]

I have a four-node 2.7.1 cluster.  I just started experimenting with
mirrored queues.  One queue is mirrored across nodes 1&2, a second queue
is mirrored across nodes 3&4.  I've been feeding a lot of large messages
through, using delivery-mode 2.  Most of the messages I've purged, since
the reader process can't keep up yet.

Here's the problem: Memory usage.  Nodes 1 & 3, presumably the master
nodes for the queues, have maintained a normal memory profile, 3-6GB. 
But nodes 2 & 4, the presumable slaves, have had their memory grow to
58GB each.  Worse, when I purged and then even deleted the queues, the
memory usage did not go down.  It seems I may have to reboot these nodes
to get the memory back, and obviously I can't use mirrored queues if
they're going to make my nodes do this, which is disappointing.  I do
have a workaround involving alternate exchanges, but the workaround can
leave data stranded if a node is lost forever.

Is there any other info I can provide to help diagnose and/or fix this?