Today memory is not serious problem, each of our server has 64GB memory.
> Forgot to add - so our FCGI servers need a lot (and I mean a lot) more
> memory than the mod_perl servers to serve the same level of content (just
> in case memory blows up with FCGI backends)
>
> -----Original Message-----
> From: James Smith <j...@sanger.ac.uk>
> Sent: 23 December 2020 11:34
> To: André Warnier (tomcat/perl) <a...@ice-sa.com>; modperl@perl.apache.org
> Subject: RE: Confused about two development utils [EXT]
>
>
> > 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)
>
>
>
>
>
> --
> The Wellcome Sanger Institute is operated by Genome Research Limited, a
> charity registered in England with number 1021457 and a company registered
> in England with number 2742969, whose registered office is 215 Euston
> Road, London, NW1 2
> <https://www.google.com/maps/search/s+215+Euston+Road,+London,+NW1+2?entry=gmail&source=g>
> BE.
>
>
>
> --
> The Wellcome Sanger Institute is operated by Genome Research
> Limited, a charity registered in England with number 1021457 and a
> company registered in England with number 2742969, whose registered
> office is 215 Euston Road, London, NW1 2
> <https://www.google.com/maps/search/s+215+Euston+Road,+London,+NW1+2?entry=gmail&source=g>
> BE.
