The challenge

Any IT system around long enough will eventually hit what industry often euphemistically refers to as ‘technical debt’. That is older technologies and protocols that we’d like to replace and/or update. In the integration space this challenge can be exacerbated by client dependencies. For example, imagine you have a SOAP API that’s serving clients and you need to replace the system, but the new and improved system only exposes REST APIs. What do you do? Avoiding this can only get you so far before you must force the issue. Addressing can be extra complicated when the calling clients are outside of your control. Especially true if the client pays for the service! 🙂

APIM to the rescue

One of the tricks we’ve found that can avoid this, involves use of an often under-appreciated service: Azure’s API Manager (APIM). Careful application of a service like APIM can often enable system updates to progress. The big benefit is avoiding awkward hostage situations where every upgrade must move at the pace of the slowest.

Above is an outline of the pattern/concept. In essence you take the old definition (e.g. your existing SOAP service WSDL) and expose it as an endpoint from APIM. The legacy client can consume the new APIM endpoint. Aside from pointing to a new URL to them it is essentially unchanged. Behind the scenes that same endpoint is ‘mapped’ via an APIM policy which prepares your new service definition and dispatches. Upon its return the response is similarly mapped back to originating caller’s protocol before being sent back. Et voila… you get to progress your system updates while clients can continue on older interface protocol until they are ready to update.

Here at DMS Group we have used this technique on many occasions. Most notably we started doing this when we were faced with old BizTalk SOAP adapter integrations that were being replaced with Azure Integration Services. However the concept is often equally applicable to other situations. If you are looking for help to avoid similar hostage situation in your own technology systems by all means reach out to DMS Group, we here to help.