12.3 Treaty Management Fortresses

Treaty management fortresses manage complex relationships among usually three or more fortresses, typically business application fortresses. I discussed the general idea of treaties in Chapter 8 (Treaties). A treaty is an agreement by two or more fortresses to work together and a description of the terms that will govern the overall collaborative relationship. Simple treaties can usually be managed directly by the participating fortresses themselves . More complex treaties often benefit from having specialized fortresses, called treaty management fortresses, orchestrate the collaboration.

Treaty management fortresses are usually based on commercial products. Probably the best-known products in this area are TIBCO's ActiveEnterprise, WebSphere MQ Integrator, and Microsoft's BizTalk Server. None of these products use the term treaty management to describe their functionality. Instead, they like to think of themselves as being at the core of the enterprise. Any of them would show the relationship between their product and the rest of your enterprise as something similar to Figure 12.8.

Figure 12.8. Treaty Management from a Vendor's Perspective

I don't envision these technologies (such as BizTalk) as being the center of your universe. Instead, I see them as having a less pretentious role ”that of holding specific collaborations together ”for several reasons.

For one, there is no reason for every system in the enterprise to plug into the treaty management technology. When using the software fortress model, we can plug into the treaty management technologies only those systems that need to have a collaborative relationship managed by that particular technology, thereby avoiding the overhead for the systems that do not have such needs. Systems that either do not collaborate or collaborate only through simple treaties have no need to use treaty management technologies.

Thinking in terms of treaty management rather than enterprise core gives us the flexibility to choose different treaty management technologies for different treaties. TIBCO's high-end ActiveEnterprise is overkill for hooking together a half- dozen fortresses that will be working with less than, say, a few thousand infograms per hour . Such a modest treaty could easily be managed with Microsoft BizTalk Server at a much lower overall cost. So my picture of these technologies looks like Figure 12.9, in contrast to the vendor's picture shown in Figure 12.8.

Figure 12.9. Treaty Management from a Software Fortress Perspective

The most common functions provided by treaty management technologies are these:

Drawbridge translation (both data and protocol)
Loosely coupled transaction management
Workflow management

Drawbridge translation refers to the bridging of drawbridges that are naturally incompatible with each other. The incompatibility can be in the infogram itself, in the protocols used to transfer the infogram , or both.

Loosely coupled transaction management is a topic I have covered several times. I described it earlier in this chapter as a possible service fortress. When treaty management technologies are being used, the framework for loosely coupled transaction management is usually included as part of the technology.

Workflow management refers to the coordination of infograms, usually infograms delivered over asynchronous drawbridges, which I discussed in Chapter 6 (Asynchronous Drawbridges). When you have a lot of fortresses throwing asynchronous infograms at each other, it can become pretty confusing as to whose turn is next . The treaty management products can help make sure that work is flowing in the proper order.

When a treaty management product is being used, it is necessary to create what these products often call a connector . A connector is a subsystem that knows how to pass messages between the managed system (usually a business application or legacy application) and the managing technology (e.g., BizTalk). From the perspective of software fortresses, the managed system is a fortress ally, a connector is an envoy, and the messaging technology linking together the manager and the managed system is a drawbridge.