Migration of a Chosen Architectural Pattern to Service Oriented ...

Chapter 3. Architectural Patterns 58Client Implicit Mechnism ServerFigure 3.24: Example usage of Implicit Invocation pattern3.2.2 Methods of patterns categorisationLiterature presents several different methods of pattern categorisations [8][38]which are meant to underline specific aspects of patterns like their structure,properties or applications. The reason why particular aspects are underlinedmay also vary in addition, may include for instance justification for architectureselection e.g. highly adaptive architectures adaptation. Source literature forarchitectural pattern section provides several different ways of pattern categorisation.Buschmann [21] presents following approaches:1. Domain –This categorisation groups all patterns that are often used in aspecific domain. An example domain can be for instance: scientific application.Most of those scientific applications need a lot of disc space toshare common data and a high performance algorithm to do calculations.In many cases, algorithms are distributed over many computers that haveto work together. This set of requirements and constrains can impose a setof most adequate patterns.2. Partition –Groups all the patterns that present a system as a stack of tiers.For instance, there can be a business tier and an integration tier. Integrationtier contains all patterns that enable easy integration and adaptation.Business tier groups patterns that improve maintainability and extendability.3. Intent –This category groups patterns in very narrow and high–specializedgroups. Each group consists of patterns that solve the same problem or helpto reduce it. For instance Intent may enclose a group of patterns that solvea problem of system distribution or a group that collects only patterns thatenables easy exchange of data.Presented categorisations of patterns start from very general idea of a domainand go deeper through grouping of pattern having structure presented as a stackof tiers. Finally, patterns having the same application are put together.The second source [38] provides only one categorisation, namely categorisationby domain of application. This approach is in fact a clarification of the domain