rabbitmq tracers

1. ymt-tracer can trace message in 10.1.0.2 cluster  in a local VM or
an openstack instance in 10.1.1.250 cluster (10.2.1.155); but the
rabbitmq (10.1.0.148) of 10.1.1.180 is in an error condition, we expect
the this tracer also work, but we have not tested it.
2. smallfish-tracer is not well tested
rally in openstack instance

this rally works in an openstack instance, definitely works in a local
VM. for 10.1.1.180 cluster, you need to explicitly assign the
shared-internal network to run rally instance, while it is not required
in 10.1.0.2. After a series of trial-and-error, we found out that in
10.1.1.180 cluster, ANY user in ANY tenant/project with an ADMIN role
can launch rally in an EXPLICIT SHARED NON-EXTERNAL network.
simple trace analysis

There are three parts included:
1. trace-split.sh to split the trace into header and payload
2. exchange-count.py to count each exchange and develop the pattern
3. exchange-plot.m to plot the exchange pattern in matlab

This is only a tentative analysis that focus on the headers which may
convey some pattern information. for a deeper analysis, we need to look
into the payload which is similar to the TCP part in an IP datagram