Benjamin Mayo, 9to5Mac:
After many complaints from the developer community about poor networking performance on Yosemite, the latest beta of OS X 10.10.4 has dropped discoveryd in favor of the old process used by previous versions of the Mac operating system. This should address many of the network stability issues introduced with Yosemite and its new networking stack.
The discoveryd process has been subject to much criticism in recent months as it causes users to regularly drop WiFi access and causes network shares to list many times over, due to bugs.
There are two weeks until WWDC, where Apple will probably introduce OS X 10.11. While that won’t be released to the public until, most likely, autumn, 10.10.4 isn’t publicly available yet either. That means that developers, at least, have been using and complaining about discoveryd for about a year, and it’s still busted for consumers.
Furthermore, I haven’t heard a compelling reason for discoveryd’s existence. It must be “better”, in some way, because I can’t think of another reason why Apple would task their engineers with rewriting the networking stack. I always assumed it was to unify iOS and OS X and to enable Continuity features, but those seem to work just fine under mDNSresponder.
Given the importance of WiFi to Apple’s computer strategy, particularly since the consumerisation of the MacBook Air in 2010, I am surprised discoveryd shipped at all.