Chapter 14. Resource-management patterns

One concern that most systems share is that you need to manage or represent resources: file storage space, computation power, access to databases or web APIs, physical devices like printers and card readers, and many more. A component that you create may provide such a resource to the rest of the system on its own, or you may need to incorporate external resources. In this chapter, we will discuss patterns for dealing with resources in Reactive applications. In particular, we will look at the following:

In the previous two chapters, we introduced the example of the batch job service, a system that allows clients to submit computation jobs in order to have them executed by a fleet of elastically provisioned worker nodes. We focused on the hierarchical decomposition and failure handling of such a system. Now we will take a closer look at the provisioning and management of the worker nodes, which are the primary resources managed by the batch job service.

14.1. The Resource Encapsulation pattern

A resource and its lifecycle are responsibilities that must be owned by one component.

14.2. The Resource Loan pattern

14.3. The Complex Command pattern

14.4. The Resource Pool pattern

14.5. Patterns for managed blocking

14.6. Summary