The Swift Proxy Server is responsible for tying together the rest of the Swift architecture.
For each request, it will look up the location of the account, container, or object in the
ring and route the request accordingly. The public API is also exposed through the Proxy
Server. A large number of failures are also handled in the Proxy Server. For example,
if a server is unavailable for an object PUT, it will ask the ring for a handoff server
and route there instead. When objects are streamed to or from an object server, they are
streamed directly through the proxy server to or from the user the proxy server does
not spool them.