Re: [Savannah-hackers-public] Memo: HTTP/2 support for Savannah (and probably *.gnu.org) and the blockers

[Bob Proulx]

Jing Luo wrote:
> Now that it's almost 2024, HTTP/2 is support by apache2 is mature, it's
> probably time for savannah and *.gnu.org to support HTTP/2. It brings better
> performance and requires TLS 1.3, but I'll leave this discussion/decision to
> FSF admins.

HTTP/2 brings more performance but also brings more vulnerabilities
too.  The performance differences for a large site like Googles is
commensurately large.  But performance difference for a small site
such as Savannah or even all of gnu.org is small.  Therefore this
seems like a much less urgent priority than other priorities.  Such as
recruiting more volunteers! :-) And doing all of the rest of the work
that is needed.

> As a memo, *IF* savannah enables HTTP/2 support, a few things have to
> change:
>
> The first thing I encountered when deploying HTTP/2 on my own server, is the
> apache2 error.log saying:

I would not even consider deploying HTTP/2 without first migrating to
Nginx.  So that would be the first step.

> > [http2:warn] [pid 42376] AH10034: The mpm module (prefork.c) is not
> > supported by mod_http2. The mpm determines how things are processed in
> > your server. HTTP/2 has more demands in this regard and the currently
> > selected mpm will just not do. This is an advisory warning. Your server
> > will continue to work, but the HTTP/2 protocol will be inactive.
>
> HTTP/2 requires the apache2 module mpm_event to be enabled. mpm_event
> conflicts mpm_prefork, and mpm_prefork is required by "php" (e.g. "php8.2").
> So the solution is to use "php-fpm" (e.g. "php-fpm8.2") instead of "php",
> and enable mpm_event and mpm_worker.

However regardless I do apprecate you communicating these tidbits.
It's generally useful information.  It's "ground truth" information
and that's always invaluable.

> I assume savannah now runs on "php" instead of "php-fpm". IIRC php-fpm is
> considered to have better performance than php because it uses workers
> instead of threads to handle connections (?). ...

Savannah is a collection of services.  Savannah's web UI is currently
running Apache and libapache2-mod-php but it's long been on my want
list to convert it to php-fpm for the reasons you describe.  Most of
the other Savannah systems run Nginx already.

Bob