Component-based architecture vs. Distributed system

Can we describe a component-based architecture as a distributed system for an example EJB is a component based architecture as well as it has qualities to become a distributed system? So how can these two concepts combine together, or to d开发者_开发问答ifferentiate.

Thanks.

"Component-based" means "separation of concerns", whether those are:

• physical (with tiers, where each "compoents" represent a physical unit of separation/deployment, like a 3-tiers architecture with a web server (1 tier) delivering web pages (another tier) which draws on data from a database the 3rd tiers. See FinnNk's answer for the question 3 Tier Architecture vs 2 Tier Architecture.

• logical (with layers with components representing responsibilities).

The term component is "generic" enough to be applied to any architecture where you can identify several concerned which can be isolated.

Hence, a distributed system can be viewed as a collection of physical components (the "nodes") or logical components (as for EJB: a server-side "component", here a "model" that encapsulates the "business logic" of an application)

In both cases you divide a system into parts.

The difference in a distributed system is that the it can be called over the wire.

You should have a look at the 4 pillars of service orientated architecture:

http://www.stsc.hill.af.mil/crossTalk/2007/09/0709LewisSmith.html