Progress
Version 9
Product Update Bulletin


AppServer Internet Adapter Architecture

Running AppServer applications over the Internet can present challenges due to the restrictive access policies enforced by many company networks. Companies often use firewalls to protect their internal systems from unauthorized access. A firewall is a computer and software that sits between a private network and the Internet. The firewall restricts the types of protocols that can travel into the internal network. The firewall often restricts the ports these protocols can use. For example, it is common to limit traffic originating outside a firewall to those applications using HTTP on port 80.

AIA is a Java servlet that is run by a Java servlet engine (JSE) and allows Java programs to run on a Web server. AIA supports deployment of distributed applications over the Web by extending the AppServer architecture to support the HTTP and HTTPS protocols. When you use AIA, communication between an AppServer client and an AppServer is encapsulated within standard HTTP requests and “tunnels” those requests through a Web server. AIA then converts requests that are encapsulated within HTTP or HTTPS to the standard AppServer protocol. This conversion process allows AppServer clients to communicate through firewalls without requiring a network administrator to allow additional protocols or ports to be accessed through a firewall.

HTTPS is HTTP on a Secure Socket Layer (SSL) connection rather than the standard unencrypted TCP/IP connection. HTTPS is used when privacy, integrity, and server authentication are needed in addition to HTTP tunneling. To use the HTTPS protocol, you can use any Progress Web-enabled client with the Client-Side Security package.

Figure C–1 illustrates the AIA and AIA/S architecture.

Figure C–1: AppServer Internet Adapter Architecture

NOTE: In this appendix, wherever you see references to the AppServer, you can usually substitute a reference to the SonicMQ Adapter. However, note that instead of accessing a database like the AppServer, the SonicMQ Adapter accesses a JMS infrastructure supported by SonicMQ, and when you configure the AIA to access a SonicMQ Adapter (instead of an AppServer), you must specify a controlling NameServer that is configured to access that SonicMQ Adapter’s application service or you must specify the hostname and port of a specific SonicMQ Adapter instance. Note also that the SonicMQ Adapter is accessible only by Progress 4GL clients (including WebClients), not by Open Clients. For more information on the SonicMQ Adapter, see the Progress External Program Interfaces manual.


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