Web Services Context WSCTX http developers sun comtechtopicswebserviceswscafwsctx
Web Services Context WS-CTX http: //developers. sun. com/techtopics/webservices/wscaf/wsctx. pdf Presented by: Ioan Toma
Overview • Introduction • Architecture – Components – Activities • WS-CTX interactions • Conclusions Ioan Toma 2
Introduction • WS-CTX allows multiple Web services to share a common context structure Ioan Toma 3
Architecture • WS-CTX represents a Web services interaction of a number of activities related to an overall application – Defines demarcation points between activates – Register Web services – Propagate context information • WS-CTX components: – Context Service – Context – Activity Lifecycle Service Ioan Toma 4
WS-CTX components Context Service – defines the scope of an activity and how information about it (the context) can be referenced and propagated in a distributed environment. – is concerned with managing the lifecycle of context propagation. Activity Lifecycle Service – offer additional information to the basic context – registered with the Context service and are informed of the lifetime of an activity Ioan Toma 5
WS-CTX components (cont) Context • contains information necessary for multiple Web services to be associated with the same activity. • is modeled as a Web resource and is accessible via a URI • consists of the following items: – – – A URI identifier - context identifier Activity-service element – Context service identifier Type of the activity identifier List of the services currently participating in the activity List of child activities Timeout value • transported in a SOAP header block Ioan Toma 6
WS-CTX Activity • is a unit of (distributed) work, involving one or more parties (services, components, objects); a way of scoping application specific work • has a status: active, completing, completed, no_activity, unknown • has a completion status: success, fail_only, unknown • has a outcome that is returned to the initial Web service application Ioan Toma 7
WS-CTX Activity (Cont) • Services involved within an activity: – Activity Lifecycle Service – Application Service Ioan Toma 8
WS-CTX interactions • Enlisting and delisting an Activity Lifecycle Service by using two interfaces – ALSRegistrar (Context Service) • enlist. ALS, delist. ALS – ALSRegistrant (ALS) • enlisted, delisted, invalid. ALSFault, general. Falut Ioan Toma 9
WS-CTX interactions (cont) • Interactions between ALS and Context Service – ALS (ALS endpoint) • begin, complete. With. Status, complete, get. Identity – ALSRespondant (Context Service endpoint) • begun, completed. With. Status, completed, identity, invalid. ALSFalut, valid. Context. Expected. Fault, general. Falut • Interaction between Context Service and Users services – CTXService • begin, complete. With. Status, set. Completion. Status, get. Activity. Name, get. Context, set. Timeout and get. Timeout – User. CTXService • begun, completed, completion. Status. Set, completion. Status, status, activity. Name, context, timeout. Set, timeout, invalid. State. Fault, invalid. Activity. Fault, timeout. Of. Range. Fault, child. Activity. Pending. Fault, no. Activity. Fault, no. Permission. Fault, valid. Context. Expected. Fault Ioan Toma 10
Conclusions • WS-CTX is intended as a lightweight mechanism for allowing multiple Web services to share a common context. • WS-CTX defines the context, the scope of context sharing, and basic rules for context management. Ioan Toma 11
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