Update notifications

New type of notifications is added to nginx-rtmp - update notifications. They are called periodically with given timeout while stream is in play or publish state. If result code is other than 2xx then connection is terminated. All usual parameters are passed with this call (including client request arguments).

application myapp {
    live on;
    notify_update_timeout 20s;
    on_update http://localhost/update;
}

Default update timeout is 30 seconds, but it can be changed with notify_update_timeout directive.
This notification can be used to synchronize expired sessions.

Update: on_update ignores server access errors, empty or broken HTTP responses. Connection is terminated only on non-2xx HTTP return code.

Update2: Added notify_update_strict directive toggling strict mode. When in strict mode all network errors and bad HTTP responses are treated as update errors. Default is off.