| 2011/04/20 - List of keep-alive / close options with associated behaviours. |
| |
| PK="http-pretend-keepalive", HC="httpclose", SC="http-server-close", |
| |
| 0 = option not set |
| 1 = option is set |
| * = option doesn't matter |
| |
| Options can be split between frontend and backend, so some of them might have |
| a meaning only when combined by associating a frontend to a backend. Some forms |
| are not the normal ones and provide a behaviour compatible with another normal |
| form. Those are considered alternate forms and are marked "(alt)". |
| |
| SC HC PK Behaviour |
| 0 0 X tunnel mode |
| 0 1 0 passive close, only set headers then tunnel |
| 0 1 1 forced close with keep-alive announce (alt) |
| 1 0 0 server close |
| 1 0 1 server close with keep-alive announce |
| 1 1 0 forced close (alt) |
| 1 1 1 forced close with keep-alive announce (alt) |
| |
| At this point this results in 4 distinct effective modes for a request being |
| processed : |
| - tunnel mode : Connection header is left untouched and body is ignored |
| - passive close : Connection header is changed and body is ignored |
| - server close : Connection header set, body scanned, client-side keep-alive |
| is made possible regardless of server-side capabilities |
| - forced close : Connection header set, body scanned, connection closed. |
| |
| The "close" modes may be combined with a fake keep-alive announce to the server |
| in order to workaround buggy servers that disable chunked encoding and content |
| length announces when the client does not ask for keep-alive. |
| |
| Note: "http-pretend-keepalive" alone has no effect. However, if it is set in a |
| backend while a frontend is in "http-close" mode, then the combination of |
| both will result in a forced close with keep-alive announces for requests |
| passing through both. |
| |