A nginx module to add a sticky cookie to be always forwarded to the same
When dealing with several backend servers, it's sometimes useful that one
client (browser) is always served by the same backend server (for session
persistance for example). A cookie is used to track the upstream server, since
balancing just by IP address, behind which multiple clients may live, can be
unfair to the load balancing.
The Sticky module can't apply when cookies are not supported by the browser.
When the sticky module can't apply, it switchs back to the classic Round Robin
Upstream or returns a "Bad Gateway" (depending on the no_fallback flag).