Software Architecture

Trade-Offs

Table 9-4. Joint ownership service consolidation technique trade-offs Advantages	Disadvantages
Preserves atomic transactions	More coarse-grained scalability
Good overall performance	Less fault tolerance
	Increased deployment risk
	Increased testing scope

Data Ownership Summary

Figure 9-10 shows the resulting table ownership assignments from Figure 9-1 after applying the techniques described in this section. For the single table scenario involving the Wishlist Service, we simply assigned ownership to the Wishlist Service, forming a tight bounded context between the service and the table. For the common ownership scenario involving the audit table, we created a new Audit Service, with all other services sending an asynchronous message to a persisted queue. Finally, for the more complex joint ownership scenario involving the product table with the Catalog Service and Inventory Service, we chose to use the delegate technique, assigning single ownership of the product table to the Catalog Service, with the Inventory Service sending update requests to the Catalog Service.
Once table ownership has been assigned to services, an architect must then validate the table ownership assignments by analyzing business workflows and their corresponding transaction requirements.

Figure 9-10. Resulting data ownership using delegate technique for joint ownership