
Chapter 4. Technical coexistence scenarios 121
Figure 4-6 Stateful interaction using multiple service providers
In Figure 4-6, we see that the messages contain a mutually agreed-upon
iStateInfo object containing state information. Because the message maintains
state, the service providers are capable of performing state-dependent
operations while the interaction remains asynchronous in nature.
In Figure 4-7 on page 122, we see that we can easily aggregate services as well
using the asynchronous paradigm while maintaining state information. Properly
engineered messages between the artifacts can help maintain the
loosely-coupled nature of thes ...