If cluster_tests.py, test_management is modified to enable durable messages, it fails the log comparison test shows messages like this on one broker but not the others:
trace Changed V1 statistics org.apache.qpid.broker:connection:127.0.0.1:52742-127.0.0.1:44104 len=NN
trace Changed V2 statistics org.apache.qpid.broker:connection:127.0.0.1:52742-127.0.0.1:44104
To date this hasn't been seen to actually cause a cluster crash but in principle it is possible it could.
To reproduce, build the message store at: http://anonsvn.jboss.org/repos/rhmessaging/store/
In the tests/cluster directory, run this in a loop:
make check TESTS=run_python_cluster_tests CLUSTER_TESTS='.test_management -DDURATION=2'
It will fail, usually on the first iteration, showing the log files that don't match. Use diff or other such tool to confirm that the mismatched lines are as above. The file may also contain some other mismatches showing a different number of stats in a periodic update - that is a consequence of the above.