[EMAIL PROTECTED] (Perrin Harkins) wrote:
>Hi Sam,
[snip]
>> I am saying that since SpeedyCGI uses MRU to allocate requests to perl
>> interpreters, it winds up using a lot fewer interpreters to handle the
>> same number of requests.
>
>What I was saying is that it doesn't make sense for one to need fewer
>interpreters than the other to handle the same concurrency. If you have
>10 requests at the same time, you need 10 interpreters. There's no way
>speedycgi can do it with fewer, unless it actually makes some of them
>wait.
Well, there is one way, though it's probably not a huge factor. If
mod_perl indeed manages the child-farming in such a way that too much
memory is used, then each process might slow down as memory becomes
sparse, especially if you start swapping. Then if each request takes
longer, your child pool is more saturated with requests, and you might
have to fork a few more kids.
So in a sense, I think you're both correct. If "concurrency" means the
number of requests that can be handled at once, both systems are
necessarily (and trivially) equivalent. This isn't a very useful
measurement, though; a more useful one is how many children (or perhaps
how much memory) will be necessary to handle a given number of incoming
requests per second, and with this metric the two systems could perform
differently.
------------------- -------------------
Ken Williams Last Bastion of Euclidity
[EMAIL PROTECTED] The Math Forum
