Question

There are three main groups of software architectural structures:
• Module structures
• Component-and-Connector Structures
• Allocation Structures
(b) Pick two of these three groups. For these two structure groups, give two (2) examples of
particular structures within that group, indicating the elements and relationships in that
structure.

Answer 1

Answer: b---------------

Component-and-Connector Structures:---------------
These structures include the following.

1. Process, or communicating processes. Like all component-and-connector structures, this one is orthogonal to the module-based structures and deals with the dynamic aspects of a running system. The units here are processes or threads that are connected with each other by communication, synchronization, and/or exclusion operations. The relation in this (and in all component-and-connector structures) is attachment, showing how the components and connectors are hooked together. The process structure is important in helping to engineer a system's execution performance and availability.
2. Concurrency. This component-and-connector structure allows the architect to determine opportunities for parallelism and the locations where resource contention may occur. The units are components and the connectors are "logical threads." A logical thread is a sequence of computation that can be allocated to a separate physical thread later in the design process. The concurrency structure is used early in design to identify the requirements for managing the issues associated with concurrent execution.
3. Shared data, or repository. This structure comprises components and connectors that create, store, and access persistent data. If the system is in fact structured around one or more shared data repositories, this structure is a good one to illuminate. It shows how data is produced and consumed by run time software elements, and it can be used to ensure good performance and data integrity.
4. Client-server. If the system is built as a group of cooperating clients and servers, this is a good component-and-connector structure to illuminate. The components are the clients and servers, and the connectors are protocols and messages they share to carry out the system's work. This is useful for separation of concerns (supporting modifiability), for physical distribution, and for load balancing (supporting run time performance).

Allocation Structures:-------------
Allocation structures include the following.

1. Deployment. The deployment structure shows how software is assigned to hardware-processing and communication elements. The elements are software (usually a process from a component-and-connector view), hardware entities (processors), and communication pathways. Relations are "allocated-to," showing on which physical units the software elements reside, and "migrates-to," if the allocation is dynamic. This view allows an engineer to reason about performance, data integrity, availability, and security. It is of particular interest in distributed or parallel systems.
2. Implementation. This structure shows how software elements (usually modules) are mapped to the file structure(s) in the system's development, integration, or configuration control environments. This is critical for the management of development activities and build processes.
3. Work assignment. This structure assigns responsibility for implementing and integrating the modules to the appropriate development teams. Having a work assignment structure as part of the architecture makes it clear that the decision about who does the work has architectural as well as management implications. The architect will know the expertise required on each team. Also, on large multi-sourced distributed development projects, the work assignment structure is the means for calling out units of functional commonality and assigning them to a single team, rather than having them implemented by everyone who needs them.