Introduction to Reverse Proxies
A reverse proxy is a server running in front of a group of servers. It presents a single interface to the caller. The reverse proxy routes all incoming connections to the servers and dispatches the inbound network traffic among them.
You can use a reverse proxy to:
Balance the load of a server cluster.
Increase the defense by adding an additional security layer.
Rewrite the URLs of the requested resources.
Reverse Proxies Managing Web Service Connections
When you have a Web service deployed on a particular system, it is exposed via the WSDL URL. To retrieve the WSDL file, you should use the internal WSDL URL that contains the host name and the port used in the internal network. If you want to use a reverse proxy to manage Web services, it should be able to change internal endpoint and WSDL URLs to external URLs. The rules of correspondence that associate an internal URL with an external URL are referred to as URL mappings.
WSDL URLs of Web services can be retrieved via WSIL, or they can be queried in the Services Registry if the Web service is published. When processing Web service query requests, the Web services framework should be aware of the available URL mappings to expose correct URLs:
You can set the URL mappings for Web services in SAP NetWeaver Administrator.
These URL mappings do not affect the Web service runtime processing. For more information, see Configuring Host Mapping, Path Prefix, and Path Mapping
You can also configure the HTTP service to set virtual host, virtual port, and transport protocol (HTTP or HTTPS) mapping for a port.
Those HTTP mappings are global and are relevant for all kind of HTTP requests. The WS HTTP mappings take priority over the global HTTP mappings. For more information, see Configuring Reverse Proxy Servers .
When external WSDL and endpoint URLs for Web services are generated, the system uses both the URL mappings for Web services and the global HTTP mappings:
The WSDL and endpoint URLs are converted for service requests coming from external networks.
Service requests originating from the internal network can use the internal URLs.