Target services and gateway services

The web services gateway makes the following distinction between a target service and a gateway service:
  • A target service is a service that is available at a service integration bus destination.
  • A gateway service is the view of a target service that the gateway gives to service requesters. It is decoupled from the target service.
  • A single gateway service can have more than one associated target service (that is, more than one implementation of the same logical service).

A target service is either an internal service (that is, an internally-hosted service directly available at a bus destination), or an external web service (that is, an externally-provided web service that has been made available at a bus destination as an outbound service).

When you configure a gateway service, the gateway service is described in a new WSDL file that is published to a gateway-controlled URL. This indirection gives the following benefits:
  • You can move the target service to a new destination, or replace it with a new implementation, and you only have to update the target service information that is held in the gateway. Existing service requesters can still find it and use it, because (as far as they can see) nothing has changed.
  • The target service destination need not be on the same bus as the gateway service destination.
  • If you have several different implementations of the same service, and you deploy them all to the gateway as multiple target services for a single gateway service, then they appear to service requesters as a single service. You can then use a routing mediation to choose the most appropriate target service for each incoming request.
  • You can set, quite independently, the security measures that apply between the service requester and the gateway service, and the security measures that apply between the gateway service and each target service.

When you create a new gateway service, you associate it with a single target service. The gateway service WSDL is created from this first target service WSDL, and you specify the location of the target service WSDL as part of the gateway service creation process. If the target service is an external Web service, it already has an associated WSDL that you can point to. If it is an internal service, create and make available a template WSDL that describes the service.


指出主題類型的圖示 概念主題



時間戳記圖示 前次更新: July 9, 2016 11:12
http://www14.software.ibm.com/webapp/wsbroker/redirect?version=cord&product=was-nd-mp&topic=cwsg_gw_target
檔名:cwsg_gw_target.html