Difference between revisions of "PAT.Application Hosting"

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Latest revision as of 06:20, 16 August 2013

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This is a Pattern document

Document icon PAT Application Hosting Version: 0.2 OIAr logo
Document type: Pattern Type Owner:

S.A.D. Jumelet


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Description

This Pattern Type belongs to "Infrastructure Sector Business Support". Application hosting provides a set of facilities to accommodate (business) application services. Accommodation entails

  • the runtime environment that the applications can use
  • a means to expose or publish the application services' results using web protocols
  • the connectivity that consumers of the application's services require for access
  • and optionally, extra functionality to service the application services.

Authentication/authorization is optionally included in the pattern type, but should preferably be performed using the pattern Access Security, as most necessary security functions are located in this pattern.

Graphical Overview

This is the graphical representation of the infrastructure functions in this Pattern Type, plus their main relations:

Application Hosting pattern type


Framed Pattern Type legend.png

(The source file of this picture can be downloaded here).

Pattern Type Composition

This pattern has the following mandatory and optional subfunctions, expressed in Building Block Types:

Icon Function WA Inclusion Rationale
BT.Application Engine icon Application Engine SE mandatory This BBT delivers the core functionality of the pattern.
BT.Presentation Engine icon Presentation Engine SE optional This BBT delivers an important part of the core functionality of any application hosting solution: the presentation of the application to the client - although an Application Hosting facility may be deployed behind a separate facility that takes care of this. The technology used here must match those available at the client (e.g. HTTP implies browser, X Window implies X Server etc)
BT.Presentation Aggregation icon Presentation Aggregation SE optional When combining multiple hosted applications, Presentation Aggregation may serve to share (presentation-specific) functionality.
BT.Scheduler icon [[|]] optional While application hosting usually responds to client request, it may be convenient to have the application also respond to other triggers; the Scheduler BBT provides the capability for this.
BT.Transaction Coordination icon Transaction Coordination MW optional When multiple instances of one business application are necessary AND the transactions that the facility must process are interdependent, then this BBT can provide the necessary coordination.
BT.Control Interface icon Control Interface SE optional The Application Hosting facility should preferably be managed by a centralized facility, but if this is not possible or feasible, then a means must be offered to manage the facility itself - and the Control Interface offers this means. Note that this facility is limited to the Application Hosting facility, and cannot directly manage the applications running on the Application Hosting facility.
BT.Message Coordination icon Message Coordination SE optional If an Application Hosting facility is to be able to offer its applications the possibility to send out messages (such as e-mail), then this function acts as intermediary between the application and the message handling service


Pattern Type Neighbors

This pattern has the following mandatory and optional relations with adjacent (sub)functions, expressed in Pattern Types (PAT). Note: if the table below is empty, then there are no architecturally prescribed relations with adjacent subfunctions:

Function Adjacency Description
optional Should the Application Hosting facility need to offer hosted applications the ability to store unstructured data, then inclusion of this pattern is needed.
Data Management optional Should the Application Hosting facility need to offer hosted applications the ability to store structured data, then inclusion of this pattern is needed.
Authentication & Authorization optional When authentication/authorization (A&A) is needed and cannot be (fully) catered for in an Access Security pattern, then the A&A facility is necessary. Authorization can be paired with Application Hosting relatively easy, but application of authorization is more secure if it takes place earlier in the traffic stream from client to application - hence the usage of Access Security --including A&A-- is preferable.
Message Handling optional This facility offers the means to deliver data to applications, and/or to enable applications to send data out. It may provide asynchronous messaging (like email or XML messages), synchronous messaging (like SOAP messages over HTTP or RPC) or both.


Pattern Variants based on this type

Pattern VariantBrief descriptionOwnermaturity
PAV.Application Hosting.Cloud - Internal Access Only Best EffortCloud - Internal Access Only Best EffortS.A.D. Jumelet3