I have merged https://github.com/icing/mod_h2/pull/280 to the mod-h2 on github. With mpm_event, this will return HTTP/2 connections more often to the mpm, thus freeing a worker.
While this sounds good, I am not sure this is beneficial for a server under load. The current connection state handling is designed for HTTP/1.x where a connection is "given back" to the MPM at the end of a request. AFAICT, the MPM assumes that, once any pending output is written, it may close the connection under load. Because in HTTP/1.x it means the connection has served the last response completely. The client should be grateful and cope well with the connection being closed subsequently due to other clients demands. In HTTP/2 so far, we did return to the MPM only when all requests had been served. The connection is therefore really in a similar state to HTTP/1.x. The client has got its responses, we are free to close. With the change in PR 280, we return on being flow blocked. The response(s) are *not* finished. If MPM now closes such a connection under load, the client will most likely try again. This seems counter productive. Therefore I am hesitant if this change is beneficial for us. It frees up a worker thread - that is good - but. Do we need a new "connection state" here? WDYT? Cheers, Stefan
