[stefantalpalaru]

Take a look at the instructions: https://www.varnish-cache.org/docs/trunk/whats-new/upgrading...

[ruben_varnish]

Ok, 5-10 min reading it.

5 min writing vcl3to4.pl and 5 min testing it.

5-10 min playing with the new varnishstat.

In total a 30 min job.

;-)

[ruben_varnish]

See, it did not take that long:

https://github.com/fgsch/varnish3to4