Systems Architecture notes Systems Architecture Notes

Terminology and Definitions

SOA - Service-oriented architecture
refers to messaging – performing services via messaging and contracts, working with fungible (interchangeable) resources, which may be published for consumption.
Factoring
distributed, rather than centralized (monolithic) architecture.
Aspects
non-functional (i.e. non-process) settings.

Atomic transactions

Two-phase commit
agreement at a single point between service spaces.
Locking
a time point.
Re-orderability
relaxes service space and time requirements.
Service agents
accommodate re-ordering.
Service Masters
manage (e.g. inventory) resources. Re-ordering is more difficult for Service Masters.

Data categories

Reference data
versioned data, needed to complete a request.
Resource-oriented data
inventory, bank balances, customer information.
Activity-oriented data
transaction data

Request-response data

Immutable data
incapable of change.
Tentative operations
implicit contract to accept & process cancellation - Increase uncertainty.

Service-level agreements

Service Masters
manage resources
Service Agents
perform processes, abiding by contracts

Data Triumvirate

  1. SQL – bounded schema
  2. XML – unbounded schema – between services
  3. Object Components – encapsulated data  - allows de-coupling interface from implementation and encapsulate data.

Microsoft

.Net Architecture

Microsoft .Net architecture components:

Dynamic Systems Initiative (DSI)
provides an enterprise object model – to blueprint systems. Distinguish always-up systems from applications.
System Definition Model SDM
an XML document.  Multiple-levels.  SDM store and service will be integrated into Windows.  Constraints, policies and settings can be modeled for deployment.
Automated Deployment & Monitoring
non-compliance will be notified, like de-bugging.  Longhorn will include monitoring service.  Task model will be standardized and application-accessible via API’s.
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