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Oracle® HTTP Server Administrator's Guide
10g Release 2 (10.1.2)
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F Frequently Asked Questions

This appendix provides answers to frequently asked questions about Oracle HTTP Server.

See Also:

"Frequently Asked Questions" in the Apache Server documentation.

Documentation from the Apache Software Foundation is referenced when applicable.


Readers using this guide in PDF or hard copy formats will be unable to access third-party documentation, which Oracle provides in HTML format only. To access the third-party documentation referenced in this guide, use the HTML version of this guide and click the hyperlinks.

F.1 Creating Application-specific Error Pages

Oracle HTTP Server has a default content handler for dealing with errors. You can use the ErrorDocument directive to override the defaults.

See Also:

"ErrorDocument directive" in the Apache Server documentation.

F.2 Offering HTTPS to ISP (Virtual Host) Customers

For HTTP, Oracle HTTP Server supports two types of virtual hosts: name-based and IP-based. HTTPS supports only IP-based virtual hosts.

If you are using IP-based virtual hosts for HTTP, then the customer has a virtual server listening on port 80 of a per-customer IP address. To provide HTTPS for these customers, simply add an additional virtual host per user listening on port 4443 of that same per-customer IP address and use SSL directives, such as Using mod_ossl Directives to specify the per-customer SSL characteristics. Note that each customer can have their own wallet and server certificate.

If you are using name-based virtual hosts for HTTP, each customer has a virtual server listening on port 80 of a shared IP address. To provide HTTPS for those customers, you can add a single shared IP virtual host listening on port 4443 of the shared IP address. All customers will share the SSL configuration, including the wallet and ISP's server certificate.

F.3 Using Oracle HTTP Server as Cache

You can use Oracle HTTP Server as a cache by setting the ProxyRequests to "On" and CacheRoot directives.

See Also:

"ProxyRequests and CacheRoot directives in the Apache Server documentation.

F.4 Using Different Language and Character Set Versions of Document

You can use multiviews, a general name given to the Apache server's ability to provide language and character-specific document variants in response to a request.

See Also:

"Multiviews" in the Apache Server documentation.

F.5 Using OracleAS Web Cache as Front-end

You can use directives such as ExpiresActive, ExpiresByType, ExpiresDefault, to set the length of time that any cache existing between the client and the Web server will cache the returned Web pages.

See Also:

"ExpiresActive, ExpiresByType, ExpiresDefault directives" in the Apache Server documentation.

F.6 Sending Proxy Sensitive Requests to HTTP Server Behind a Firewall

You should use the Proxy directives, and not the Cache directives, to send proxy sensitive requests across firewalls.

F.7 mod_oc4j Information

mod_oc4j is a module that integrates with Web servers, typically Oracle HTTP Server, and routes request to the backend OC4J processes. OPMN module keeps mod_oc4j aware of the status of different OC4J processes, so mod_oc4j routes only to the processes that are up and running. mod_oc4j also understands the concepts of Oracle Application Server Clusters and OC4J islands, and routes accordingly to provide as much transparent failover as possible.

See Also:


F.8 mod_oc4j Compatibility with Other Web Servers

mod_oc4j supports other Web servers including IIS, Sun ONE, and non-Oracle HTTP Server Apache Servers.

F.9 mod_oc4j Communication to OC4J using SSL

The AJP communication between mod_oc4j and OC4J processes can now be over AJP/SSL. Previously, this was in the clear. Also, the SSL negotiation does not happen each time mod_oc4j and OC4J communicate, resulting in less performance impact.

F.10 Oracle HTTP Server Version Number

Oracle HTTP Server is based on Apache version 1.3.31.

F.11 Applying Apache Security patches to Oracle HTTP Server

You cannot apply the Apache security patches to Oracle HTTP Server for the following reasons:

F.12 Compressing Output from Oracle HTTP Server

In general, Oracle recommends the use of OracleAS Web Cache for this purpose. There are other freeware modules, such as mod_gzip that may be plugged in for this purpose, but their use is not supported. When using these, there may be an error message with respect to EAPI, but in general that can be ignored.

F.13 Supporting PHP

mod_php is fully supported in Release 2 (10.1.2).

See Also:


F.14 Creating Namespace that Works Across Firewalls, Clusters, Web Cache

The general idea is that all servers in a distributed Web site should agree on a single URL namespace. Every server serves some part of that namespace, and is able to redirect or proxy requests for URLs that it does not serve to a server that is "closer" to that URL. For example, your namespaces could be the following:


We could initially map this namespace to two Web servers by putting app1 on server1 and app2 on server2. Server1's configuration might look like the following:

Redirect permanent /app2 http://server2/app2
Alias /app1 /myApps/application1
<Directory /myApps/application1>

Server2's configuration is complementary. If you decide to partition the namespace by content type (HTML on server, JSP on server2), change server configuration and move files around, but do not have to make changes to the application itself. The resulting configuration of server1 might look like the following:

RedirectMatch permanent (.*) \.jsp$ http://server2/$1.jsp
AliasMatch ^/app(.*) \.html$ /myPages/application$1.html
<DirectoryMatch "^/myPages/application\d">

Note that the amount of actual redirection can be minimized by configuring a hardware load balancer like F5 system's BigIP to send requests to server1 or server2 based on the URL.

F.15 Protecting Web Site From Hackers

There are many attacks, and new attacks are invented everyday. The following are some general guidelines for securing your site. You can never be completely secure, but you can avoid being an easy target.