A6_DistArchCh2 - Architectures for Distributed Systems...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Architectures for Distributed Systems Chapter 2
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Definitions Software Architectures – describe the organization and interaction of software components; focuses on logical organization of software (component interaction, etc.) System Architectures - describe the placement of software components on physical machines The realization of an architecture may be centralized (most components located on a single machine), decentralized (most machines have approximately the same functionality), or hybrid (some combination).
Background image of page 2
Architectural Styles An architectural style describes a particular way to configure a collection of components and connectors. Component - a module with well-defined interfaces; reusable, replaceable Connector – communication link between modules Architectures suitable for distributed systems: Layered architectures* Object-based architectures* Data-centered architectures Event-based architectures
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Architectural Styles Figure 2-1. The (a) layered architectural style & (b) The object-based architectural style. Object based is less structured component = object connector = RPC or RMI
Background image of page 4
Data-Centered Architectures Access and update of data store is the main purpose of the system Processes communicate/exchange info primarily by reading and modifying data in some shared repository (e.g database, distributed file system) Traditional data base (passive): responds to requests Blackboard system (active): clients solve problems collaboratively; system can update clients when information changes.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Architectural Styles Figure 2-2. (a) The event-based architectural style Communication via event propagation, in dist. systems seen often in Publish/ Subscribe; e.g., register interest in market info; get email updates Decouples sender & receiver; asynchronous communication Event-based arch. supports several communication styles: • Publish-subscribe • Broadcast Point-to-point
Background image of page 6
Architectural Styles (5) Figure 2-2. (b) The shared data-space architectural style. Data Centric Architecture; e.g., shared distributed file systems or Web-based distributed systems Combination of data-centered and event based architectures Processes communicate asynchronously
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Distribution Transparency Software architectures are important because they are designed to support distribution transparency. Transparency involves trade-offs Different distributed applications require different solutions/architectures There is no “silver bullet” – no one-size-fits-all system.
Background image of page 8
System Architectures for Distributed Systems Centralized : traditional client-server structure Vertical (or hierarchichal) organization of communication and control paths Logical separation of functions into client (requesting process) and server (responder) Decentralized : peer-to-peer Horizontal rather than hierarchical comm. and control Communication paths are less structured; symmetric functionality
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/14/2011 for the course CS 690 taught by Professor Staff during the Fall '11 term at University of Alabama - Huntsville.

Page1 / 53

A6_DistArchCh2 - Architectures for Distributed Systems...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online