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Context Rules (context data type)

The protocols and constraints applied to the execution of a specific service activity are collectively referred to as context rules. These rules may be predetermined during the service composition design; however, there may also be context rules that are dynamically determined at runtime in response to certain scenarios and conditions.

Examples of context rules include:

  • the allowable duration of the service activity
  • the allowable quantity of service activity instances
  • the allowable quantity of participating services

Another common form of context rules governs the transaction management of a service activity, such as whether the service activity is wrapped in an ACID-like transaction (that supports abort, commit, or rollback) or whether the activity is long-running (and relies on a compensation process to deal with exception conditions).

The WS-Coordination context framework is supplemented by two additional specifications that introduce context rules expressed via industry-standard SOAP headers. The WS-AtomicTransaction specification provides ACID-style protocols and the WS-BusinessActivity specifications provides context rules for long-running service activities.

Context rules represent one of two context data types, the other being context data. Context data types are of relevance to the application of the Service Statelessness design principle.


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