Rails - Apr 2006 - Reload an application without restarting the Server?

Hi, I would like to set up a "shared hosting"-like rails environment
on
a linux (+Apache1.3 +FastCGI +MySQL) machine. As we all know, rails 
provides support for different environments.

Now I would like to enable my "users" to switch individual
applications
between development and production mode. In theory, all they have to do 
is to add "ENV[''RAILS_ENV''] ||=
''production''" into their environment.rb.

The problem is, that the production environment caches the rails 
application and once you have entered production mode you cannot switch 
back without killing the FastCGI processes or restarting the webserver.

I know that its possible because the RailsFCGIHandler has methods called 
resart!, restore! and reload! that exactly that but they are private and 
I don''t know how to obtain a reference to RailsFCGIHandler from a Rails
ActionController within that application.

I would like to have some kind of reload script or an admin page with 
the button: "Reload Application"...

(And no, I can''t just restart the server because its a shared hosting 
environment so there are other (non-rail/ruby) applications running on 
that same server)

-- 
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You mean, there is no way I can reload a production application without 
restarting  the _whole_ server????


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Posted via http://www.ruby-forum.com/.

Christian Klauser wrote:
> You mean, there is no way I can reload a production application without 
> restarting  the _whole_ server????
No need to restart the web server, check out script/process/reaper and 
spawner

-- 

Ray

You could probably kill a given user''s FCGI processes with a shell 
script; new ones should get spawned as needed. Try that.

I guess you could also have the production environments run in an 
individual Mongrel or Lighttpd instance that you proxy through Apache. 
Then the users could restart those to their hearts'' content. Just 
guessing.

Still seems fishy to host a single instance of an app and switch it 
between development and production modes. I''d think most people would 
want to develop locally and only host the production version of the 
site, and that the remaining folks who can''t or won''t install
MySQL and
Rails on their own PC would want both environments available 
simultaneously so they don''t have to take down their site every time 
they want to develop.

Christian Klauser wrote:
> You mean, there is no way I can reload a production application without 
> restarting  the _whole_ server????

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Posted via http://www.ruby-forum.com/.

Christian Klauser wrote:
> You mean, there is no way I can reload a production application without 
> restarting  the _whole_ server????
The other way to do it would be to use like "ps -A | grep 
/username/appname/dispatch.fcgi" then just kill those fcgi processes. I 
use a similar method to reload my app hosted on textdrive 
(www.miami-bid.com) when ever I do an svn-update. The exact syntax of 
that would be a little complicated, probably, but perfectly doable.

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Thanks for the answers. You saved my day! :-)

Steve Koppelman wrote:
> I guess you could also have the production environments run in an 
> individual Mongrel or Lighttpd instance that you proxy through Apache. 
> Then the users could restart those to their hearts'' content. Just 
> guessing.
Might be an idea. I''ve never done that though.
> Still seems fishy to host a single instance of an app and switch it 
> between development and production modes.
I do plan to develop locally but at some point I would like to patches 
I''ve uploaded. Or maybe I can''t reproduce a bug locally so I
would like
to be able to  run the web app in dev mode.

Thank you guys!

-- 
Posted via http://www.ruby-forum.com/.

>From the Agile book:
> killall -USR1 dispatch.fcgi
does a graceful restart of all currently running fcgi processes on *nix. 
Always works for me.

- michael.

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Posted via http://www.ruby-forum.com/.

I know this is probably going to sound like a broken record, but check out
Capistrano. I use it on Textdrive (shared), and for multiple apps on my VPS,
and it''s the easiest way to deploy/restart an app, especially if
you''re
already using SVN (which I also highly recommend). It can be a little bit of
work to get it going, but now that I use it I can''t imagine deploying
without it. It will automatically call reaper and spawner to restart your
app for you.

Matt

On 4/18/06, michael lascarides <michael@electrotone.com>
wrote:
>
> >From the Agile book:
>
> > killall -USR1 dispatch.fcgi
>
> does a graceful restart of all currently running fcgi processes on *nix.
> Always works for me.
>
> - michael.
>
> --
> Posted via http://www.ruby-forum.com/.
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> Rails mailing list
> Rails@lists.rubyonrails.org
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>
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Matt White wrote:
> I know this is probably going to sound like a broken record, but check 
> out
> Capistrano. I use it on Textdrive (shared), and for multiple apps on my 
> VPS,
> and it''s the easiest way to deploy/restart an app, especially if
you''re
> already using SVN (which I also highly recommend). It can be a little 
> bit of
> work to get it going, but now that I use it I can''t imagine
deploying
> without it. It will automatically call reaper and spawner to restart 
> your
> app for you.
> 
> Matt
Hm... sounds useful too. I''ve never used subversion or CVS but that 
might be worth a try too. Thx! :-)


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Christian Klauser wrote:
> Matt White wrote:
>> I know this is probably going to sound like a broken record, but check 
>> out
>> Capistrano. I use it on Textdrive (shared), and for multiple apps on my
>> VPS,
>> and it''s the easiest way to deploy/restart an app, especially
if you''re
>> already using SVN (which I also highly recommend). It can be a little 
>> bit of
>> work to get it going, but now that I use it I can''t imagine
deploying
>> without it. It will automatically call reaper and spawner to restart 
>> your
>> app for you.
>> 
>> Matt
> 
> Hm... sounds useful too. I''ve never used subversion or CVS but
that
> might be worth a try too. Thx! :-)
Ok... I''m still working on it but the main problem is, that I (=my
shell
account) don''t have permissions to kill (send any signals ot) the 
"dispatch.fcgi" processes... I haven''t trief capistrano yet
but I bet it
uses something like `kill -9 #{pid}` too... Please correct me if I''m 
wrong...

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