We currently have an Oracle Application Server 9i application which we are planning to convert to use Oracle Application Server 10g. As part of this process, we are considering the conversion of our application from a 3-tier to a 4-tier architecture. Much of the architecture will remain the same except for the addition web tier, as our web and application tiers are currently combined. My main concerns revolve around our Apache installation.
I will appreciate it if someone will provide a list of the main aspects of this architecture change that we will need to address. Essentially, we currently have 1 web/application server that serves all requests from web users, and users can go to one of 3 regions we have set up (two for testing and training and one for production). Apache resides on this web/application server and serves all of these requests. We are interested in moving Apache to the new web tier, and placing the 3 regions on separate application servers.
I do not think this task will be difficult, but do not know all of the items we need to address. For example, what will we need to do regarding our SSL certificate? If the web tier is confined to one box, do we need one - or more - SSL certificates? What about ports between the two tiers? Can we still use one main web address?
Thank you very much. I appreciate it.
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So, if 3 Apache instances reside on one web server, we will need only one SSL certificate?
And despite the fact that each Apache instance will need a different port for access from the web, we can still use the same web address for all instances?
If you can direct me to some documentation that explains how to address this type of scenario, I will greatly appreciate it.
Thanks again.
> So, if 3 Apache instances reside on one web server, we will need only one SSL certificate?
only if they have all the same domain (FQDN)
If they run phsically on the same machine, but use different IPs (and FQDN) then you need a cert with wildcar for the host, for example *.your.tld I.g. I personally would not trust a domain cert, only FQDN certs.
What I am not understanding is how each of the Apache instances residing on the proposed web server will be able to know which requests to respond to, if each of the Apache instances needs to point to a specific application server based on which application server the user needs to communicate with. So in my previous example, if there are two Apache instances on one web server, each of which serves requests for two distinct and separate application servers, how is it determined to which Apache instance the user request will be sent, and to which user to reply?
you would need to use different ports, default port = 80, you will need to use 8080 and possibly 8081 or something like that, the websites would then be accessed like:-
www.example.com
www.example.com:8080
www.example.com:8081
Its not possible to have two services listening on the same ports
I dont know your apache version!
http://httpd.apache.org/do
http://httpd.apache.org/do
http://httpd.apache.org/do
Please elaborate upon your previous suggestion, "ahoffman". Upon elaboration I will reward you the points unless someone else elaborates prior to your response.
To summarize, what I am looking to do is the following: (1) use one web server with two instances of Apache, (2) use two application servers, one of which is for testing and one of which is for production, (3) route testing user requests from client browsers to the testing application server via the testing instance of Apache, and (4) route production user requests from client browsers to the production application server via the production instance of Apache. Note that the web server has one IP address.
a) what do you mean with "web server"? Apache is a web server. Or do you mean a physical computer with "web server" while you mean a software instance/process for Apache?
b) what is a "application server" for you? do you mean a physical computer or a software (like Tomcat)?
c) what is a "testing user request"?
d) what do you mean with "route ... requests"?
e) what is a "production user request"?
Well, I could guess on most of these/my questions, but it sounds like we do not yet agree on the same terminology.
> Note that the web server has one IP address.
if you mean that a "web server" is one physical computer for you, then you have to use different ports if you want to run more than one instance of apache on it.
Yes, "ahoffman", I was sensing that our definitions of the various terms we were using might be at odds. My last post attempted to clarify further, but it appears my clarification was not thorough enough.
The scenario I proposed involved one physical hardware server which acts as the "web server", and two physical hardware servers which act as the "application servers". This web server has two instances of the Apache HTTP Server (Apache). Each of these application servers has a separate instance of Oracle Application Server 10g installed. One of these application servers acts as the testing server, and one of these application servers acts as the production server. If the user seeks to access the testing server, client browser requests need to go through the instance of Apache which points to the testing server. If the user seeks to access the production server, client browser requests need to go through the instance of Apache which points to the production server.
In a previous reply, you had stated that separate ports are NOT needed, so I needed to understand how the two Apache instances can be configured to not require separate ports. "JB04" appeared to disagree with your statement that separate ports were not needed, so I needed someone to clarify which was the case. If we are now to say that separate ports are needed, is there anything else which needs to be considered when setting up the two separate instances of Apache on the one physical hardware server? Also, is there a way to NOT require the port to be included in the URL when attempting to connect to the Apache instance located at the non-default port?
Thanks.
> you would need to use different ports,
"no, see my previous suggestion"
ahoffmann, Im keen to see what your suggestion is now, seen as your quick to play down other suggestions and think your way is the only way, Electrokardiogram could have avoided a lot of hassle by doing it the way I suggested!
BTW, You dont actually need two apache instances to run apache on two different ports, see the links I posted.
You could setup a subdomain instead, which would avoid using different ports altogether, seen as the servers are on one machine.
James
well you could even configure the primary apache instance listening on IP:80 as proxy, which redirects local to to other instances of apache listening on localhost:81 and localhost:82
But then you need to tell the client browsers that to use different URLs, like
http:/IP/for-81/blahblah
http:/IP/for-82/blahblah
which then is processed by the proxy
This does not require additional IPs, nor additional ports, nor subdomains, just a proper URL schema.
Does this now clarify why I first disagreed with "need different ports"?
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by: ahoffmannPosted on 2006-02-02 at 13:45:40ID: 15857609
> For example, what will we need to do regarding our SSL certificate?
each web server needs its own cert
> What about ports between the two tiers? Can we still use one main web address?
you only need one port, i.g. 80, public accessable, all other ports from your web servers to the other applpication servers (tiers) can use other ports as you like. And I highly recommend that you bind these servers to localhost only.
> Can we still use one main web address?
yes