Blackboard Software Architecture

Adriana ContrerasAlex Garcia

Karen RichartBegoña Beorlegui

Heriberto Gonzalez

What is it?

• Blackboard is an architectural model where a problem is solved by a group of specialists.

What problem does it solve?• Allows the solution of

complex problems where the solution is the sum of the specialists’ contributions.

How does it solve the problem?

Who are the actors?

• The actors are the Knowledge sources that contribute with a partial solution of the problem.

• A control shell that moderates the flow of the problem solution.

How do they relate to each other• They relate to each other by

the problem that they collaboratively need to solve.

InterpreterTeam 2

What is an Interpreter?

• A “virtual machine” that parses and executes input commands

• Actors:oHardwareoProgram

What does it do?

• Improves portability of the software

• Supports flexibility with other architectural styles

• Highly dynamic behavior allowed

What is it made of?

• Interpreters generally have four components: • interpretation engine• memory• representation of the control state• representation of the current state

Sources• http://www.cs.cmu.edu/afs/cs/project/vit/ftp/pdf/intro_softarch.pdf• http://sunset.usc.edu/classes/cs578_2012b/05_Architectural_Styles.ppt• http://www.thomasalspaugh.org/pub/fnd/architecture.html#Interpreter• http://coronet.iicm.tugraz.at/sa/s5/sa_styles.html

Plug-in ArchitectureTeam 3

Plug-in Architecture What is Plug-in Architecture?

Framework that allows programs or applications to find add-in functionalities from plug-ins when starting up and allow the plug-ins to apply their functionalities with the current program or application.

What problem does Plug-in Architecture solve and how does it solve it? Solves the problem of feature bloat by enabling the customizing of the

functionality of an application. By allowing outside features to be added to an application, the

developer is able to have a release that is smaller in size and does not contain unnecessary and often unused features.

Overall, applications support plug-ins for several reasons, including: to enable third-party developers to create abilities which extend an

application to support easily adding new features to reduce the size of an application to separate source code from an application because of

incompatible software licenses.

Plug-in Architecture Actors:

Host Application: Loads the plug-in and provides an interface for the plug-in.

Plug-In: Module that is dependent on a host application and adds functionality to the host application.

How are these actors related? The host application provides

service which the plug-in can use.

Plug-ins depend on servicesprovided by the host, while the host operates independently of the user. End-users are able to

add and update plug-insdynamically, without needing to make changes to the host application.

Plug-in Architecture Some examples of applications which use plug-ins, and why, include:

Email clients use plug-ins to decrypt and encrypt email (Pretty Good Privacy) Graphics software use plug-ins to support file formats and process images

(Adobe Photoshop) Media players use plug-ins to support file formats and apply filters (Winamp,

Windows Media) Software development environments use plug-ins to support programming

languages (Eclipse, jEdit, MonoDevelop) Web browsers use plug-ins (often implementing the NPAPI specification) to

play video and presentation formats (Flash, QuickTime, Microsoft Silverlight, 3DMLW)

Sources Playing with Plugins. (2012, June 18). How do plugins work. [Online] Available:

http://www.youtube.com/watch?v=OX60XS1uERg UCL Information Services Division. (1999-2013). How “plugins” work. Stowell,

Dan. [Online] Available: http://www.ucl.ac.uk/isd/staff/e-learning/tools/plugins P. Qualls. (2002, June 13). Plug-in Architecture Framework for Beginners [Online]

Available: http://www.codeguru.com/cpp/misc/misc/plug-insadd-ins/article.php/c3879/Plugin-Architecture-Framework-for-Beginners.htm

Plug-in (computing). (2013, January 23). In Wikipedia, The Free Encyclopedia. [Online] Available: http://en.wikipedia.org/w/index.php?title=Plug-in_(computing)&oldid=534573505

Search-Oriented ArchitectureTeam 4

Search-Oriented Architecture What is it?

Search engine technology replaces or supplements a relational database management system

SQL queries are replaced by keyword or fielded searches for: Structured Semi-structured Unstructured data

Is a three-tier architecture

Solve the problem Response time in large dynamic datasets

Drawback The data tier is not as organized

Search-Oriented Architecture Who are the actors?

User Database

In Depth Look of Search-Oriented Design

Search-Oriented Architecture References

http://www.mediabuzz.com.sg/asian-emarketing/november-2011/1424-search-oriented-architecture

http://www.courses.utep.edu/Portals/870/f12-s13/cs4311-Spring13/class%20lectures/L05-%20Software%20Architectures.ppt

http://www.soainstitute.org/sites/default/files/images/contributors/Paradkar_March11_2_Figure1.jpg

Space-Based Architectures

Team 5 – Software Eng. 2 – Spring 2013

What is Space-Based Architecture? Organize related data and business

logic together into processing units (PU); a compartmentalization of applications that allows for the emulation of various software architectures.

Source: Browne, Julian.“Space-based Agility”. June 25, 2007 http://www.julianbrowne.com/article/viewer/space-based-agility

Why Space-Based Architecture? Problem:

What happens when the perfect software architecture is ruined by a business or client’s new requirements?

Solution: Make the applications within software more modular. Encapsulate an application’s data and business logic

together; aka a processing unit (PU). Adding/removing an application is modular.Provide a tuple space (aka space) for objects that can be used concurrently by applications.

Sources: 1. Nair, Anup H. “Distributed Space based architecture”. May 27, 2012 http://www.hificoding.com/general/46-distributed-space-based-architecture2. Mordinyi, Richard et al, “Space-based Architectures as Abstraction Layer for Distributed Business Applications”. 2010 IEEE

Space-Based Architecture Actors

Tuple Space: Containers

coordinators, aspects, entries Processing Units

How do the actors relate to each other? Processing Units can access objects. Objects are tuples inside of containers. Containers are internet addressable.

Source: Mordinyi, Richard et al, “Space-based Architectures as Abstraction Layer for Distributed Business Applications”. 2010 IEEE

Shared Nothing Architecture

Shared nothing – is a distributed computing architecture. There is no central unit and each part of the system acts independently. Ex. Several Processors share neither

common memory nor common disk

Shared Nothing Architecture

Solves bottle necking and scalability Independent nodes act as part of a

system, but do no rely on each others availability

SN is infinitely scalable and only limited by the number of node you can incorporate

Shared Nothing Architecture

Actors Nodes are the actors and they act in

their own process space. They act asynchronously and are race-free.

They act independently but are components of a larger system

Shared Nothing ArchitectureExample:

Shared Nothing ArchitectureSources:

The Case for Shared Nothing Architecture by Michael Stonebraker. [Originally published in Database Engineering, Volume 9, Number 1 (1986).] http://db.cs.berkeley.edu/papers/hpts85-nothing.pdf

Shared Nothing v.s. Shared Disk Architectures: An Independent View by Ben Stopford, Tuesday, November 24th, 2009  http://www.benstopford.com/2009/11/24/understanding-the-shared-nothing-architecture/

Publisher-Subscriber Software EngineeringTeam 7

publish–subscribe is a messaging pattern where senders of messages, called publishers, do not program the messages to be sent directly to specific receivers, called subscribers.

published messages are characterized into classes, without knowledge of what, if any, subscribers there may be.

Subscribers express interest in one or more classes, and only receive messages that are of interest, without knowledge of what, if any, publishers there are.

AdvantagesLoose couplingPublishers are loosely coupled to subscribers, and need not even know of their existence. With the topic being the focus, publishers and subscribers are allowed to remain ignorant of system topology.

ScalabilityPub/sub provides the opportunity for better scalability than traditional client–server, through parallel operation, message caching, tree-based or network-based routing, etc.

Publisher-Subscriber

• http://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern

• https://docs.google.com/viewer?a=v&q=cache:9GTjK1kOFY8J:www.softwarearchitecturebook.com/svn/main/slides/ppt/05_Architectural_Styles.ppt+&hl=en&gl=us&pid=bl&srcid=ADGEESi4y7caTUsrkQ6O-71Ob8ZEU84_TlvHRMU_-OHLFvy6Z8PMvL2zXLjUf52v6adTmijcZnUq2oXBtjB0_613o3h3Rh02l8fnyIc6MhZV38lO-koNhou2t30aaF6VzEBecvi_Vk_7&sig=AHIEtbRQWykLrdZ8CW7aK57M4e33Es4N9w