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Comment by veesahni | Hacker News Reader

Does Falcon + Async allow a second request to be processed while the first is blocked on a network call?

For example:

* HTTP request 1 requires information for which we can't respond immediately.. so we hold the connection open and respond in a few seconds.

* Can HTTP request 2 come in at the same time?

EventMachine enabled the above with what they called "streaming responses"

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That seems mostly like the question of "Does this HTTP framework support HTTP pipelining". While I don't know the answer, it doesn't seem highly relevant. Most clients went away from using pipelining, since follow-up requests on the same connection are subject to unknown latency (stuck behind the first request) and a connection failure can impact all of those requests.

The better approach is to use either more connections, or proper request multiplexing via HTTP/2 or /3. In the latter case a server framework would just see multiple request invocations in parallel.

> subject to unknown latency (stuck behind the first request)

Also known as "head of line blocking" https://en.wikipedia.org/wiki/Head-of-line_blocking

No, that's a different thing. HTTP request 2 from this scenario is from an entirely different client on an entirely different socket connection.

(This kind of architecture might also be useful for http pipelining, but that's not the question in this scenario)

Yes, this is possible!

In fact this is a perfect use case for Falcon + Async.

I just tried this out. Falcon with count=1 & sinatra. Worked perfectly. It seems every request is processed in an async block so literally no special code is required. A request waiting on network will allow others to go through.

This is awesome! :)

It does, and that’s specifically why I’m really looking forward to benchmarks for rack frameworks switching to falcon - while it may not take Rails to Phoenix’s performance and latency, I bet it would close the gap considerably.

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