[Mono-list] mod_mono and swapping out web application assemblies

Gonzalo Paniagua Javier gonzalo.reply.to.the.list.iam.subscribed@ximian.com
Wed, 14 Jul 2004 01:31:39 +0200

El mar, 13-07-2004 a las 18:23, Jim Erwin escribió:
> I know mod_mono is a bit behind the core release of mono in terms of
> maturity, however there is an issue I've come across that I'd like to
> find a way to resolve, or at least find a best practice to handle it.
> If I simply want to change the assemblies in the bin folder of a web
> application with IIS/Windows from a VS.NET compiled project, I can
> simply copy over the old ones. At this point, JIT compilation and
> caching occur as soon as the next page hit occurs without any other need
> for admin intervention. The same is not true when using mod_mono.

There are bug reports covering this issue. Search for ShadowCopy in

> When I simply swap out assemblies with mod_mono, I get errors that the
> classes can't be found. At this point, the only thing I know to do that
> works is to run "killall mono" from a root prompt. At this point, the
> server processes are restarted and on the next page hit, the JIT
> compilation takes place. All is well. The down side of this as I see it
> is that this will kill ALL mono applications on the box. So if I'm
> running multiple web applications, or other non-web mono applications on
> the server, all of them get killed at this point.

Last week I did some changes to mod_mono. Now, if you let mod_mono fork
mod-mono-server when needed, reloading/restarting/stopping apache will
properly finish it and relaunch when necessary. Killing by hand is not
needed any more.

> A perfect resolution would be to have mod_mono treat new assemblies the
> same way IIS does on Windows. I'm assuming that this may take quite a
> bit of work to implement or may never be done. The next option would be
> to have a utility where you can pass which application needs to be
> reloaded for a web application and have all of the behavior for that
> handled in the background. The question is then how to determine which
> instances of "mono mod-mono-server.exe" are attached to a specific web
> application.
> Thoughts and ideas on how to resolve this would be greatly appreciated.

Ideally, we would only need to unload the appdomain of the application
you want to restart (or do it automatically when, for example,
global.asax is changed) but there are still a few bumps on the road (all
of them in bugzilla).

The «easiest» thing to do that would help us with this issues is
supporting ShadowCopyFiles.