Oracle9iAS Portal Developer Kit
A Primer on using Proxy Servers for Providers (v2)

Oracle9iAS Portal can be configured to use proxy server when making requests. Proxy servers intercept requests to another server and forward the requests to the real server as needed. They are generally used for forwarding requests through a firewall, filtering content and caching content.

This article describes the key features of proxy support within Oracle Portal and also how to configure Web providers (registered with Oracle Portal) to use proxy servers.

Key Features

These are the key features of proxy support within Portal:

- Multiple proxy servers can be specified in Oracle Portal.
- Oracle Portal can be configured to use different proxy servers for different Web providers.
- Oracle Portal middle-tier and database-tier can be configured individually to use the required proxy servers for provider communication.
- A proxy for all non provider requests made by Oracle Portal can also be specified.

How to Add Proxy Server Settings

Only Portal Administrators can add Proxy Server Settings as follows:

1. Click the Proxy Settings link in the Services portlet (on Administer tab).
2. Specify the Host Name and Port Number for the proxy server
3. Click Add.
4. Repeat steps 2 and 3 to add other proxy servers.
5. If certain domains don't require a proxy server to be used, list such domains under the No Proxy Domain section.

Note: You can also add proxy server settings via the APIs. For details, refer to the PL/SQL API Reference for WWCTX_API_PROXY (available in 9.0.2).

How to use Proxy Servers for Web Providers

Some of the Oracle Portal calls to Web providers originate from the Portal repository (database-tier). The calls to a Web provider's Show method originate from the Portal middle-tier. During Web provider registration, proxy servers for both middle-tier and database-tier communications can be specified individually. The choice of Proxy servers depends on the configuration of the Portal middle-tier and the repository.

In this article, we consider three sample configurations of the Portal repository and middle-tier with firewall and discuss how to specify the proxy servers based on these configurations during provider registration. Lets assume that the Proxy servers used in this example are primarily used to connect to servers outside of firewall and that have been specified within Oracle Portal via the Proxy Settings page.

Sample Configuration 1 - Portal Repository and Middle-Tier within the Same Firewall

Figure 1 shows both the Portal middle-tier and repository behind the same firewall. They require a proxy server (P1) to connect to Web provider WP1 outside this firewall. In this case, the same proxy can be selected for both middle-tier and database-tier in the Provider registration screen. Figure 1 shows Proxy P1 is used by both the Portal repository and Portal middle-tier.
Sample Configuration 2 - Portal Repository and Middle-Tier are Separated by a Firewall and both are Surrounded by another Firewall

Figure 2 shows the Portal middle-tier behind a firewall and that it requires a proxy to connect to the Portal. This Proxy needs to be specified in the middle-tier. For details on how to specify proxy setting in the middle-tier to connect to the Portal repository, refer to the Oracle9iAS Portal Configuration Guide.

- The Portal middle-tier uses proxy server P2 to contact the repository and this is specified in the middle-tier. It also uses Proxy P1 to connect to Web provider WP1 outside the firewall.
- The Portal repository uses proxy server P3 (configured to use P1) to contact Web provider WP1.

In the Provider Registration screen for Web provider WP1, Proxy P1 must be selected as the middle-tier proxy and Proxy P3 as the database-tier proxy.

Sample Configuration 3 - Portal Repository and Middle-Tier are Separated by a Firewall and Web Provider is Outside the Firewall

Figure 3 shows the Portal repository within a firewall and both the Web provider and Portal middle-tier outside this firewall. The middle-tier uses proxy server P1 to connect to the database and this must be specified in the Portal middle-tier. For details on how to specify proxy setting in the middle-tier to connect to the Portal repository, refer to the Oracle9iAS Portal Configuration Guide.

The Portal database uses proxy server P2 to connect to Web provider WP1 outside of the firewall. No proxy server is specified for the middle-tier during Web provider registration.

Proxy Servers and Database Providers

There are no proxy servers involved in calls from the Portal repository to database providers. However, if the configuration is such that the Portal middle-tier requires a proxy server to connect to the database (see samples 2 and 3 above), the proxy server needs to be specified in the middle-tier. For details on how to specify proxy setting in the middle-tier, refer to the Oracle9iAS Portal Configuration Guide.

Revision History:

January 17, 2002.