Fork!

Ever heard of fork?

using GLib;
using VSGI.HTTP;

var server = new Server ("", () => {
    return res.expand_utf8 ("Hello world!");
});

server.listen (new VariantDict ().end ());
server.fork ();

new MainLoop ().run ();

Yeah, there’s a new API for listening and forking with custom options…

The fork system call will actually copy the whole process into a new process, running the exact same program.

Although memory is not shared, file descriptors are, so you can have workers listening on common interfaces.

I notably tested the whole thing on our cluster at IRIC. It’s a 64 cores Xeon Core i7 setup.

wrk -c 1024 -t 32 http://0.0.0.0:3003/hello

With a single worker:

Running 10s test @ http://0.0.0.0:3003/hello
  32 threads and 1024 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    54.35ms   95.96ms   1.93s    98.78%
    Req/Sec   165.81    228.28     2.04k    86.08%
  41741 requests in 10.10s, 5.89MB read
  Socket errors: connect 35, read 0, write 0, timeout 13
Requests/sec:   4132.53
Transfer/sec:    597.28KB

With 63 forks (64 workers):

Running 10s test @ http://0.0.0.0:3003/hello
  32 threads and 1024 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    60.83ms  210.70ms   2.00s    93.58%
    Req/Sec     2.99k   797.97     7.44k    70.33%
  956577 requests in 10.10s, 135.02MB read
  Socket errors: connect 35, read 0, write 0, timeout 17
Requests/sec:  94720.20
Transfer/sec:     13.37MB

It’s about 1500 req/sec per worker and an speedup of a factor of 23. The latency is almost not affected.

A Day in a Pile of Work

Fork! in Valum