Re: GLIB for a webserver

[Liam R E Quin <liam holoweb net>]

On Thu, 2011-12-08 at 11:13 -0200, Marcelo Elias Del Valle - SYSMAP
SOLUTIONS - Claro MA-SP - wrote:

> - On Apache ARP project, they said they created it instead of using
> glib because the lack of IPC functions like memory mapping.

This makes no sense since they could use glib and also write mmap
functions...

> - In some forums, people were complaining about the fact glib aborts
> when memory allocation fails, which is bad for a 24/7 running web
> server.

A robust Web server would probably have a framework that restarted
components as needed; Apache already does some of this with "workers".

The main problem with memory allocation comes when someone else's
process is using all the memory.

If you are writing a new Web server (why?) glib is probably fine.

Don't fight it, though. There's no portable way to find the system's
free memory, and even if there were, it wouldn't help -

    if (amount_of_memory < amount_available) {
         // imagine that after that test succeeds,
         // your program happens to get swapped out,
         // and another program allocates all of memory

         allocate_memory(); // fails
    }

So it's better to assume that things will fail. Robustness does not come
from avoiding failure - it comes from recovering from failure.

For a Web server that may just mean restarting. Sure, some users will
have to reload Web pages; if that's actually a problem, use persistent
storage to record state.

Apache and IIS are fairly large codebases for a reason, though -- a
secure reliable production Web server would have a lot of catching up to
do.

But, it's fun writing Web servers :-)

Liam

-- 
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/