Service Statelessness

“Services minimize resource consumption by deferring
the
management of state information when necessary.”

The management of excessive state information can compromise the availability of a service and undermine its scalability potential. Services are therefore ideally designed to remain stateful only when required. Applying the principle of Service Statelessness requires that measures of realistically attainable statelessness be assessed, based on the adequacy of the surrounding technology architecture to provide state management delegation and deferral options.

Figure 1 – Incorporating a balanced and targeted measure of state management deferral can significantly enhance the scalability of individual services, an important design consideration for services that are shared across multiple compositions.

SOA Principles of Service Design by Thomas Erl – Chapter 11: Service Statelessness (State Deferral and Stateless Design) explores the options and impacts of incorporating stateless design characteristics into service architectures.

Related Service-Orientation Computing Goals

Increased Intrinsic Interoperability, Increased ROI, Increased Organizational Agility, Reduced IT Burden

Related SOA Patterns

Asynchronous Queuing,
Atomic Service Transaction,
Capability Composition,
Capability Recomposition,
Messaging Metadata,
Partial State Deferral,
Process Centralization,
Service Grid,
Service Instance Routing,
State Messaging,
State Repository,
Stateful Services