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On Wed, Dec 23, 2020 at 5:05 PM James Smith <j...@sanger.ac.uk> wrote:
>
> > This costs memory, and all the more since many perl modules are not
> thread-safe, so if you use them in your code, at this moment the only safe
> way to do it is to use the Apache httpd prefork model. This means that each
> Apache httpd child process has its own copy of the perl interpreter, which
> means that the memory used by this embedded perl interpreter has to be
> counted n times (as many times as there are Apache httpd child processes
> running at any one time).
>
> This isn’t quite true - if you load modules before the process forks then
> they can cleverly share the same parts of memory. It is useful to be able
> to "pre-load" core functionality which is used across all functions {this
> is the case in Linux anyway}. It also speeds up child process generation as
> the modules are already in memory and converted to byte code.
>
> One of the great advantages of mod_perl is Apache2::SizeLimit which can
> blow away large child process - and then if needed create new ones. This is
> not the case with some of the FCGI solutions as the individual processes
> can grow if there is a memory leak or a request that retrieves a large
> amount of content (even if not served), but perl can't give the memory
> back. So FCGI processes only get bigger and bigger and eventually blow up
> memory (or hit swap first)
>
>
>
>
>
> --
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> company registered in England with number 2742969, whose registered
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