Fiber based HTTP client for load testing

[ikod]

On Thursday, 1 October 2020 at 00:35:49 UTC, Arun wrote:
> I have a REST client that can do load test of my REST services. 
> It uses ikod's dlang-requests under the hood. 
> https://github.com/ikod/dlang-requests
>
> At the moment I use a thread pool to dispatch the runtime 
> operation and send the requests to the server.

> As seen, the downside is that the more threads we use the more 
> memory the app consumes. Is there a way to replace the threads 
> with fibers in this particular case so that instead of spawning 
> 1000 threads, we spawn 1000 fibers with just 1 thread?

Hello, you can use requests with vibe.d sockets. You'll get the 
idea from example:

---
dub.json:
{
	"authors": [
		"me"
	],
	"copyright": "Copyright © 2020, me",
	"dependencies": {
		"requests": "~>1.1.7",
		"vibe-d": "~>0.9.2"
	},
	"description": "A minimal D application.",
	"license": "proprietary",
	"name": "t",
	"subConfigurations": {
     	    "requests": "vibed"
	}
}

---
import vibe.core.core;
import vibe.core.log;
import requests;

static void workerFunc(string url)
{
     logInfo("Param: %s", url);
     Request rq;
     rq.verbosity = 1;
     auto rs=rq.get(url);
     logInfo("response code: %s", rs.code);
}

void main()
{
     auto urls = ["http://httpbin.org/", 
"http://httpbin.org/image"];
     foreach(url; urls)
     {
         runWorkerTask(&workerFunc, url);
     }
     runApplication();
}
---
> GET / HTTP/1.1
> User-Agent: dlang-requests
> Host: httpbin.org
> Connection: Keep-Alive
> Accept-Encoding: gzip,deflate
> 
> GET /image HTTP/1.1
> User-Agent: dlang-requests
> Host: httpbin.org
> Connection: Keep-Alive
> Accept-Encoding: gzip,deflate
> 
< HTTP/1.1 200 OK
< date: Thu, 01 Oct 2020 03:07:33 GMT
< content-type: image/png
< content-length: 8090
< connection: keep-alive
< server: gunicorn/19.9.0
< access-control-allow-origin: *
< access-control-allow-credentials: true
< HTTP/1.1 200 OK
< date: Thu, 01 Oct 2020 03:07:33 GMT
< content-type: text/html; charset=utf-8
< content-length: 9593
< connection: keep-alive
< server: gunicorn/19.9.0
>> Connect time: 210 ms, 805 μs, and 9 hnsecs
>> Request send time: 293 μs and 2 hnsecs
>> Response recv time: 205 ms, 378 μs, and 9 hnsecs
< access-control-allow-origin: *
[vibe-6(ZLjs) INF] < access-control-allow-credentials: true
response code: 200
>> Connect time: 210 ms, 749 μs, and 6 hnsecs
>> Request send time: 307 μs and 6 hnsecs
>> Response recv time: 205 ms and 922 μs
[vibe-3(cfzw) INF] response code: 200