Erlang: The Movie

There’s also “Erlang the Movie”; the designers of Erlang demo some of the qualities of the Erlang system in a delightful way: this video

The author doesn't talk a lot about preemptive scheduling, which is probably the best thing about the Erlang virtual machine. This video explains what preemptive scheduling is and why it is extremely useful: link First, the speaker creates an application endpoint that runs into an infinite loop on invalid input. Then, he shows how that doesn't block the rest of the requests. Using native BEAM (EDIT: BEAM = EVM = Erlang Virtual Machine) tools, he looks for the misbehaving process (the one running the infinite loop), prints some debug information and kills it. It's pretty impressive. Another great (and lighter) resource, is "Erlang the Movie" ( this video ). It shows the power of concurrency through independent processes, the default debug tools, and the power of hot code reloading. Don't miss the twist at the end.

It is one of the core features of Erlang (a language developed by Ericsson), being able to rewrite code in production, with errors/crashes that break one thread not affecting another. Obligatory link to Erlang: The Movie (10min)- this video Note that they start crashing things in Erlang around minute 7, and fix them shortly thereafter. Meanwhile, their setup keeps calls that weren't directly involved in the crash alive and running unaffected.