concurrency - Writing scaleable code -

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can describe in simple terms how scale service (lets assume service simple , function x() ).

to make scalable fire off new node (upto maximum depending on hardware) each client wants run x?

so if had 4 hardware boxes, may fire 4 nodes run service x(), on 5th client request run x() on first node, 6th client on second node etc?

following on this, know how spawn processes locally, how both 1st , 5th clients use same node 1- spawning process remotely on node client each time?

any simple examples welcome!

this depends on x is. if x independent, instance x() -> 37. don't need connect nodes. place standard load balancer in front of system (haproxy, varnish, etc) , forget kind of distributed communication. in fact, there no need use erlang that. replace erlang other language of choice. equally good.

where erlang shines when several x functions have dependencies on each others result , when x might live on physical machine. in case erlang can communicate other x seamlessly, if lives on different node.

if want implement round-robin scheme in erlang, easiest way have single point of entry , let forward requests out multiple nodes. bad if there pattern node ends long-running processes. need build mechanism of feedback know how weight round-robin queue.


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