use with sinatra and don't block

[jots]

I'm using falcon with sinatra (set :server, %w[falcon] ) and trying to get it to handle multiple requests in a non blocking fashion.

I have this route:

get "/r/:name" do |name|
  r = R.do_all(name) # this is blocking for about a second
  r.to_json
end

I test it with:
ab -c 10 -n 10 http://localhost:4567/r/name
I would expect that to take about 1 second, but it takes about 10.

Is there something else I need to do to make it not block?

[ioquatix]

What does R.do_all do?

[tobidelius]

@jots just found this and after a quick peek it looks like it's only the IO operations that are run async, á la node.js :). That means that reading the file system, doing database calls etc will allow another fiber to do its work.

Would you mind describing what R.do_all is doing?

@ioquatix or perhaps I got it wrong?

[ioquatix]

@sandelius Even reading from the file system will block the entire reactor. There are trade-offs in the design of such a system and also limitations within Ruby itself. Ideally, we could yield while reading from the file system. In practice, network operations are the highest latency.

[tobidelius]

@ioquatix ahh sounds fair

[ioquatix]

It's trivial enough to design a thread pool to handle blocking / computational workloads, e.g.

https://github.com/socketry/async-process/blob/master/lib/async/process/child.rb