Dedicated threads for handling requests to endpoints with HTTP.jl

General Usage
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1

Say I’m running a HTTP.jl server, that serves two endpoints /one and /two.

Requests to /one will start a computation-based task asynchronously and return a Response with a 200 status code. This task can be assumed to take some time to execute.

On the other hand, /two is as an endpoint that doesn’t start a compute-intensive task but is used for logging purposes (i.e., the client uses the response to perform updates/logging that is based on the server’s internal state that is returned). This response can essentially be instantaneously returned.

using HTTP
const ROUTER = HTTP.Router()
HTTP.@register(ROUTER, "POST", "/one", start_compute_intensive_task)
HTTP.@register(ROUTER, "GET", "/two", get_logging_values)

Now, suppose a client makes a POST request to /one, followed by a GET request to /two.
The task started by start_compute_intensive_task essentially takes up all the compute provided by the server and thus significantly delays the request(s) made to /two from being handled.

Is there any way, to assign say one thread dedicated to handling requests made to /two?

Is there any other way I can ensure that requests made to /two are always instantly handled, even if there’s a computationally intensive task started by start_compute_intensive_task running already?

2

You may want to consider Threads.foreach (Multi-Threading · The Julia Language), specifying limit to n-1 of available threads. That is for start_compute_intensive_task function.

So always have 1 spare thread available for get_logging_values

1 Like
3

You can probably adapt the example I posted here: HTTP.jl#798.

2 Likes
4

Thanks, @fredrikekre! A slightly different variant of your example that was more compatible with my use case is what I ended up doing. :slightly_smiling_face: