> Response latency makes scripting language unacceptable for some types of problems. But in my experience very few latency problems I've come across are down to language choice vs. badly written database queries, lack of caching etc.
5 ms you save in your runtime -- for free, without any work on your part -- is 5 ms longer you can now afford to spend waiting on the database.
> But there are also plenty of situations where in-memory queues are also not acceptable, and the moment you hit disk, the entire performance profile shifts so dramatically that you suddenly often have much more flexibility.
I can only disagree here. I view CPU cycles and memory as a bank account. If you waste them on an inefficient runtime, you can't spend them elsewhere, and there are always places where they can be spent.
Excluding huge sections of the problem domain -- such as "decoding/encoding framed packet data" -- is a cop-out. There's no valid reason for it, unless you're going to go so far as to claim that Ruby/Python et al increase developer efficiency over other language's baselines so dramatically that it outweighs the gross inefficiency of the languages.
5 ms you save in your runtime -- for free, without any work on your part -- is 5 ms longer you can now afford to spend waiting on the database.
> But there are also plenty of situations where in-memory queues are also not acceptable, and the moment you hit disk, the entire performance profile shifts so dramatically that you suddenly often have much more flexibility.
I can only disagree here. I view CPU cycles and memory as a bank account. If you waste them on an inefficient runtime, you can't spend them elsewhere, and there are always places where they can be spent.
Excluding huge sections of the problem domain -- such as "decoding/encoding framed packet data" -- is a cop-out. There's no valid reason for it, unless you're going to go so far as to claim that Ruby/Python et al increase developer efficiency over other language's baselines so dramatically that it outweighs the gross inefficiency of the languages.