My Fancy Blog

Mustafa Paltun

Why Joe Armstrong hates shared state?

I stumbled across an awesome quote by Joe Armstrong when he was explaining the reason why he hates threads and shared state on a Hacker News Thread (It was an email conversation actually):


In distributed systems there is no real shared state (imagine one machine in the USA another in Sweden) where is the shared state? In the middle of the Atlantic? - shared state breaks laws of physics. State changes are propagated at the speed of light - we always know how things were at a remote site not how they are now. What we know is what they last told us. If you make a software abstraction that ignores this fact you’ll be in trouble.


I heard/read similar ideas from him but not in those words and I actually quite like it.

I’ll miss him even though I never met him in person but read his writings, watched presentations, retweeted him and (of course) implemented fair amount of programs with Erlang.

RIP Joe.