Clients sometimes hold open connections "just in case" they might later
pipeline requests. This can cause issues for proxies, especially if
operators restrict max_clients in an effort to improve response times
for the requests that *do* get serviced.
Add a new keepalive_timeout option to give proxies a way to drop these
established-but-idle connections without impacting active connections
(as may happen when reducing client_timeout). Note that this requires
eventlet 0.33.4 or later.
Change-Id: Ib5bb84fa3f8a4b9c062d58c8d3689e7030d9feb3
469c38e9fb