Weblogic-学习笔记（3课 术语）

Web Client

A Web Client interacts with WLS via HTTP using servlets/JSPs.
Types of Web clients include:

• Browser
• Web services(SOAP over HTTP)
  

Client Application

A client application interacts with WLS through JRMP/T3.IIOP,COM.
Types of clients include:

• Standalone Java applications
• Applets within a browser
  

Proxy Server

Forwards requests to other machines
Can be used as a level of indirection and security
Can be used to load balance a system

Firewalls

Provide filtering,authorization,and authentication services.
Help keep out hackers
Map port requests
Can act as proxy servers
Can decrease back-end network activity

Web Server

Web servers:
Provide Web content

• Communicate via HTTP,FTP,and so forth
• Can handle CGI requests
• Proxy some requests to application servers
  

Application Servers

Provide services that support the execution and availability of deployed applications
Handle heavier processing chores than Web servers.

A Web App Server Configuration

An Application Server Configuration

Definition : Domain

A domain is a logically related group of Weblogic Server resources that you manage as a unit.

A domain provides one point of administration.

A Weblogic Server domain can logically separate:

• Development,test,and production applications
• Organizational divisions
  

Why Use Domans?

A domain is an administration feature that;

• Is transparent to applications
• Can be configured and administered,for technical or business reasons,even after applications are developed or in production

Weblogic Server domains can be used to separate:

• Development,test and production applications
• Administration and operational responsibilities
• Organizational or business divisions

Definition : Server

A server is an instance of weblogic.server executing in a JVM.
A server:

• Runs on a designated WLS machine
• Has a dedicated amount of RAM
• Is multithreaded
  

Administration Server

Is the central point of control for a domain Stores the configuration information and logs for a domain

Runs the Weblogic Administration Console

Definition : Managed Server

Is any server in a domain that is not the admin server

Contacts the admin server for configuration information

Runs business applications in a production evironment

Definition : Machine

Is a computer that hosts Weblogic Server(s) Runs a supported operating system platform

Can host multiple Weblogic Server instances

Definition : Cluster

A cluster is a logical group of WLS servers.

Weblogic clusters provide automatic:

• High Availability
• Load balancing

A cluster is transparent to a client.

Section Review

In this section we discussed:
The ways that distributed systems improve availability,scalability,and maintainability

The ways that standards for distributed systems improve the cost effectiveness of software development projects

The J2EE architecture and many J2EE technologies

The terms used to discuss Web architectures

The terms used to describe Weblogic Server features