Benjamin Mayo, writing for 9 to 5 Mac:
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.
Yosemite was not Apple’s finest hour, but I’m happy they’re willing to do what’s necessary to make it right.