Re: [summary] Re: front end proxy and virtual hosts
Looks good; I'd recommend keeping *.html files on the front-end as well, since they tend to be static, and also any traditional *.cgi since they don't need mod_perl's bloat on the fork/exec. Also, specifying "Port 80" inside each virtual on the back-end is not necessary, though perhaps setting a new DocumentRoot might make sense. Perhaps this paragraph: If your server is configured to run traditional CGI's as well as mod_perl CGI programs, then it would be beneficial to configure the front-end server to run the traditional CGI's directly. This can be done by altering the Cgif|jpg|png|txt rewrite rule to add C|cgi at the end, or adding a new rule to handle all C/cgi-bin/* locations locally. Similarly, static HTML pages can be served by the front-end server by adding C|html to the rule. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D.Khera Communications, Inc. Internet: [EMAIL PROTECTED] Rockville, MD +1-301-545-6996 PGP MIME spoken herehttp://www.kciLink.com/home/khera/
Re: front end proxy and virtual hosts
On Mon, 10 Apr 2000, Eric Cholet wrote: The front-end light server, serving static requests and proxying dynamic requests to a back-end modperl server, is well documented, except in the case of virtual hosts. How do you do it? On the front end: VirtualHost www.customer.com DocumentRoot /vhosts/customer ProxyPass/perl/ http://localhost/customer/perl/ ProxyPassReverse /perl/ http://localhost/customer/perl/ /VirtualHost On the back end: DocumentRoot /vhosts BindAddress 127.0.0.1 Directory /vhosts/*/perl SetHandler perl-script PerlHandler Apache::Registry # Or whatever PerlSendHeader On Options +ExecCGI /Directory - Matt
[summary] Re: front end proxy and virtual hosts
=head1 Front-end Back-end Proxying with Virtual Hosts This section explains a configuration setup for proxying your back-end mod_perl servers when you need to use Virtual Hosts. The approach is to use unique port number for each virtual host at the back-end server, so you can redirect from the front-end server to localhost::1234, and name-based virtual servers on the front end, though any technique on the front-end will do. If you run the front-end and the back-end servers on the same machine you can prevent any direct outside connections to the back-end server if you bind tightly to address C127.0.0.1 (Ilocalhost) as you will see in the following configuration example. The front-end (light) server configuration: VirtualHost 10.10.10.10 ServerName www.example.com ServerAlias example.com RewriteEngine On RewriteOptions 'inherit' RewriteRule \.(gif|jpg|png|txt)$ - [last] RewriteRule ^/(.*)$ http://localhost:4077/$1 [proxy] /VirtualHost VirtualHost 10.10.10.10 ServerName foo.example.com RewriteEngine On RewriteOptions 'inherit' RewriteRule \.(gif|jpg|png|txt)$ - [last] RewriteRule ^/(.*)$ http://localhost:4078/$1 [proxy] /VirtualHost The above front-end configuration handles two virtual hosts: Iwww.example.com and Ifoo.example.com. The two setups are almost identical. The front-end server will handle files with the extensions I.gif, I.jpg, I.png and I.txt internally, the rest will be proxified to be handled by the back-end server. The only difference between the two virtual hosts settings is that the former rewrites requests to the port C4077 at the back-end machine and the latter to the port C4078. The back-end (heavy) server configuration: Port 80 PerlPostReadRequestHandler My::ProxyRemoteAddr Listen 4077 VirtualHost localhost:4077 ServerName www.example.com Port 80 DirectoryIndex index.shtml index.html /VirtualHost Listen 4078 VirtualHost localhost:4078 ServerName foo.example.com Port 80 DirectoryIndex index.shtml index.html /VirtualHost The back-end server knows to tell which virtual host the request is made to, by checking the port number the request was proxified to and using the appropriate virtual host section to handle it. We set S"Port 80" so that any redirects don't get sent directly to the back-end port. To get the Ireal remote IP addresses from proxy, the LMy::ProxyRemoteAddr|scenario/Getting_the_Remote_Server_IP_in_ handler is used based on the Cmod_proxy_add_forward Apache module. Prior to mod_perl 1.22+ this setting must have been set per-virtual host, since it wasn't inherited by the virtual hosts. The following configuration is yet another useful example showing the other way around. It specifies what to be proxified and than the rest is served by the front end: RewriteEngine on RewriteLogLevel 0 RewriteRule ^/(perl.*)$ http://127.0.0.1:8052/$1 [P,L] RewriteRule ^proxy:.* - [F] ProxyRequests on NoCache * ProxyPassReverse / http://www.example.com/ So we don't have to specify the rule for the static object to be served by the front-end as we did in the previous example to handle files with the extensions I.gif, I.jpg, I.png and I.txt internally. __ Stas Bekman | JAm_pH--Just Another mod_perl Hacker http://stason.org/ | mod_perl Guide http://perl.apache.org/guide mailto:[EMAIL PROTECTED] | http://perl.orghttp://stason.org/TULARC/ http://singlesheaven.com| http://perlmonth.com http://sourcegarden.org --
RE: front end proxy and virtual hosts
This leads me to believe that the Rewrite engine is ignored when an Alias kicks in, otherwise the *.shtml files would be bounced back to the back-end server where they get properly expanded. Normally, this is ok for me since everything else in the aliased directory is an image which I want the front end to handle. Has this bitten anyone else? Stas, I think you should mention this in the guide somehow as something to watch out for when using the proxy front-end. The Rewrite rules are ignored when an Alias expands the URI, or so it seems from where I sit. Actually I got bitten by the opposite, my Alias directives are ignored when Rewrite kicks in. I assume it depends on the Apache module order, and as Ask explained when one trans handler returns OK the other is of course ignored, so I too had to convert my Alias statements to rewrite rules. -- Eric
Re: front end proxy and virtual hosts
On Mon, 10 Apr 2000, Eric Cholet wrote: Port based backend servers is the easiest. Use Port 80 Listen 127.0.0.1:8088 (or whatever) Listen 127.0.0.1:8089 ... in your backend setup to make sure it never reveals the real port and only listens on the loopback interface (if that's what you want). Then the frontend can be setup in any way you like and proxy the requests to the appropiate port on the backend. - ask -- ask bjoern hansen - http://www.netcetera.dk/~ask/ more than 70M impressions per day, http://valueclick.com
Re: front end proxy and virtual hosts
I just ran into a bit of a conflict with Alias and Rewrite on my front end. Given that I have multiple virtual hosts serving up the same content using a slightly different set of graphics and templates, the easy way is to "Alias /_pageparts /real/page/parts/directory" and make the alias different for each virtual host. Then every document refers to /_pageparts/XXX.yyy for the component it wants, and the proper one based on the virtual host is used. Something like this: VirtualHost 204.117.82.12 ServerName next.morebusiness.com RewriteEngine On RewriteOptions 'inherit' # handle GIF and JPG images directly RewriteRule \.(gif|jpg|png|css|txt|cgi)$ - [last] RewriteRule ^/cgi-bin - [last] # pass off everything but images to the heavy-weight server via proxy RewriteRule ^/(.*)$ http://localhost:4079/$1 [proxy] DocumentRoot /web/morebusiness/nextdocs Alias /_pageparts /web/morebusiness/nextdocs/_pageparts-default /VirtualHost and on the back-end Listen 4079 VirtualHost localhost:4079 ServerName next.morebusiness.com Port 80 DocumentRoot /web/morebusiness/nextdocs DirectoryIndex index.brc index.shtml index.html Alias /_pageparts /web/morebusiness/nextdocs/_pageparts-default /VirtualHost One of the objects inside _pageparts-default is PAGEFOOT.shtml. If I do a lynx -source 'http://next.morebusiness.com/_pageparts-default/PAGEFOOT.shtml' The page comes across fine. If I do lynx -source 'http://next.morebusiness.com/_pageparts/PAGEFOOT.shtml' I get the page dumped raw. That is, the SSI constructs are ignored. If I enable .shtml files to be server-parsed on the front-end server, then both return the processed result. This is my work-around. This leads me to believe that the Rewrite engine is ignored when an Alias kicks in, otherwise the *.shtml files would be bounced back to the back-end server where they get properly expanded. Normally, this is ok for me since everything else in the aliased directory is an image which I want the front end to handle. Has this bitten anyone else? Stas, I think you should mention this in the guide somehow as something to watch out for when using the proxy front-end. The Rewrite rules are ignored when an Alias expands the URI, or so it seems from where I sit. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D.Khera Communications, Inc. Internet: [EMAIL PROTECTED] Rockville, MD +1-301-545-6996 PGP MIME spoken herehttp://www.kciLink.com/home/khera/
Re: front end proxy and virtual hosts
On Wed, 12 Apr 2000, Vivek Khera wrote: [...] Has this bitten anyone else? Stas, I think you should mention this in the guide somehow as something to watch out for when using the proxy front-end. The Rewrite rules are ignored when an Alias expands the URI, or so it seems from where I sit. They're both Trans handlers in the normal case. So if mod_alias runs first and matches it will return OK and mod_rewrite won't see the request. So it shouldn't be a surprise. :) I think the advice to give is to not mix them. mod_rewrite does everything mod_alias does - (except for ScriptAlias which is not really relevant on this list anyway) - so if you need mod_rewrite for a set of urls, use it exclusively. - ask -- ask bjoern hansen - http://www.netcetera.dk/~ask/ more than 70M impressions per day, http://valueclick.com
Re: front end proxy and virtual hosts
"ABH" == Ask Bjoern Hansen [EMAIL PROTECTED] writes: ABH mod_alias does - (except for ScriptAlias which is not really relevant on Duh. Ya know, sometimes you stare and stare and stare and it doesn't come to you. I don't even need mod_alias at all... Thanks!
front end proxy and virtual hosts
Hi, The front-end light server, serving static requests and proxying dynamic requests to a back-end modperl server, is well documented, except in the case of virtual hosts. How do you do it? Specifically, do you setup virtual hosts on the backend server? Different IPs, or different ports? Or just a flat url space, using mod_rewrite on the front-end to translate the urls? The modperl guide is sadly lacking any information in this area, so your input will be valuable. Thanks, -- Eric
Re: front end proxy and virtual hosts
"EC" == Eric Cholet [EMAIL PROTECTED] writes: EC do you setup virtual hosts on the backend server? Different IPs, or EC different ports? Or just a flat url space, using mod_rewrite on the EC front-end to translate the urls? I think I posted this example earlier. This is just a snippet of the relevant portions of the front/back end virtual configs. It is not a cookie-cutter example! Basically, I use unique port number virtuals on the back-ends (so I can redirect to localhost: bypassing some networking cruft) and name-based virtuals on the front end, though any technique on the front end will do. I set "Port 80" on the back-end so that any redirects don't get sent directly to the back-end. Sometimes I also bind tightly to address 127.0.0.1 to prevent any outside connections when the two are on the same box. Stas, feel free to incorporate this example. front end: VirtualHost 204.117.82.12 ServerName www.morebusiness.com ServerAlias morebusiness.com RewriteEngine On RewriteOptions 'inherit' # handle GIF and JPG images directly RewriteRule \.(gif|jpg|png|css|txt|cgi)$ - [last] RewriteRule ^/cgi-bin - [last] # pass off everything but images to the heavy-weight server via proxy RewriteRule ^/(.*)$ http://localhost:4077/$1 [proxy] Alias /_homepage /web/morebusiness/docs/_homepage-default Alias /_pageparts /web/morebusiness/docs/_pageparts-default /VirtualHost VirtualHost 204.117.82.12 ServerName govcon.morebusiness.com RewriteEngine On RewriteOptions 'inherit' # handle GIF and JPG images directly RewriteRule \.(gif|jpg|png|css|txt|cgi)$ - [last] RewriteRule ^/cgi-bin - [last] # pass off everything but images to the heavy-weight server via proxy RewriteRule ^/(.*)$ http://localhost:4078/$1 [proxy] Alias /_homepage /web/morebusiness/docs/_homepage-govcon Alias /_pageparts /web/morebusiness/docs/_pageparts-govcon /VirtualHost back-end: Port 80 Listen 4077 VirtualHost localhost:4077 ServerName www.morebusiness.com Port 80 DirectoryIndex index.brc index.ibrc index.shtml index.html ### # # Get "real" remote IP address from Proxy and set it as our connection's # IP address so logging, etc., use that IP address. Uses mod_perl handler. # For some reason, must be set per-virtual host. # ### PerlPostReadRequestHandler My::ProxyRemoteAddr Alias /_homepage /web/morebusiness/docs/_homepage-default Alias /_pageparts /web/morebusiness/docs/_pageparts-default /VirtualHost Listen 4078 VirtualHost localhost:4078 ServerName govcon.morebusiness.com Port 80 DirectoryIndex index.brc index.ibrc index.shtml index.html PerlPostReadRequestHandler My::ProxyRemoteAddr Alias /_homepage /web/morebusiness/docs/_homepage-govcon Alias /_pageparts /web/morebusiness/docs/_pageparts-govcon /VirtualHost
RE: front end proxy and virtual hosts
EC do you setup virtual hosts on the backend server? Different IPs, or EC different ports? Or just a flat url space, using mod_rewrite on the EC front-end to translate the urls? I think I posted this example earlier. This is just a snippet of the relevant portions of the front/back end virtual configs. It is not a cookie-cutter example! Basically, I use unique port number virtuals on the back-ends (so I can redirect to localhost: bypassing some networking cruft) and name-based virtuals on the front end, though any technique on the front end will do. I set "Port 80" on the back-end so that any redirects don't get sent directly to the back-end. Sometimes I also bind tightly to address 127.0.0.1 to prevent any outside connections when the two are on the same box. Vivek, Thanks a lot for your input. ### # # Get "real" remote IP address from Proxy and set it as our connection's # IP address so logging, etc., use that IP address. Uses mod_perl handler. # For some reason, must be set per-virtual host. # ### PerlPostReadRequestHandler My::ProxyRemoteAddr This is no longer necessary with mod_perl = 1.22, i.e. it can be put in the main server config and will be inherited (merged) in virtual hosts. -- Eric
Re: front end proxy and virtual hosts
On Mon, 10 Apr 2000, Eric Cholet wrote: The front-end light server, serving static requests and proxying dynamic requests to a back-end modperl server, is well documented, except in the case of virtual hosts. How do you do it? Specifically, do you setup virtual hosts on the backend server? Different IPs, or different ports? Or just a flat url space, using mod_rewrite on the front-end to translate the urls? I use static IP's and virtualhosts on the front-ends (we're investigating using our Foundry ServerIron load balancer to rewrite the HTTP headers to allow for name-based virtual servers on the front-ends). mod_rewrite handles proxying the dynamic requests and apparently mod_proxy automatically adds the correct headers for name-based virtual hosts on the back end. This all takes a while to setup, but it works flawlessly once it is done. -- -- Tom Mornini -- InfoMania Printing and Prepress
