Ceph

use Colin's multiprocess framework to do a messenger test for reconnects, with socket failure injects.

types:
- client->server (lossy, e.g. client/osd, client/mon)
- client->server (lossless, e.g. client/mds)
- server/server (mds, osd, mon intracluster)
- racing connections. someting like barrier, send messages to each other, make sure they both arrive, barrier, mark down, repeat.

- inject socket errors, verify all messages go through (all types)