rr.vcl

vcl 4.0;

import std;
import directors;

backend a1 { .host = "192.0.2.11"; }
backend a2 { .host = "192.0.2.12"; }
backend a3 { .host = "192.0.2.13"; }
backend a4 { .host = "192.0.2.14"; }

backend b1 { .host = "192.0.2.11"; }
backend b2 { .host = "192.0.2.12"; }
backend b3 { .host = "192.0.2.13"; }
backend b4 { .host = "192.0.2.14"; }

sub vcl_init {
    new rrA = directors.round_robin();
    rrA.add_backend(a1); rrA.add_backend(a2);
    rrA.add_backend(a3); rrA.add_backend(a4);

    new rrB = directors.round_robin();
    rrB.add_backend(b1); rrA.add_backend(b2);
    rrB.add_backend(b3); rrA.add_backend(b4);
}


sub vcl_recv {
    set req.backend_hint = rrA.backend();
    if (req.http.AppVersion == "aabbcc") {
        set req.backend_hint = rrB.backend();
    }