4 ms·

My last project saturated a cluster of computers for days at a time. Not everyone writes crud screens for day to day work, honest. Parallelism is about perfor

• ramchip 10y ago
  Erlang was built as a concurrent language for fault tolerance, not performance. The best example of a trade-off I can think of is the preemptive scheduling: Erlang switches between processes very often, which has a cost in performance but ensure the system stays responsive even if some tasks are doing intensive work (or even stuck in an infinite loop). Every function call, allocation, etc. increments a counter which is used to decide when a process is scheduled out, so that's significant overhead you pay to get a more predictable system. Some other examples are live code loading, which means you can upgrade a system without restarting or interrupting it, the extensive tracing and statistics, etc. All these little things make it very nice to build and maintain a long-running service, but add up to make the VM slower. If you're doing batch jobs and have no realtime requirement, then the trade-off may not be so attractive.