39 web client technology

39 web client technology

 

Browser works (core module)

1. Page rendering (HTML) - rendering engine, is the core of the browser; when compatibility testing, as long as the attention to the rendering engine, the same engine can choose a
   • Example: Trident (Microsoft -IE); Gecko; KHTML; 
2. JavaScript parsing and execution
3. Network Processing: It is not the core technology;
4. Data storage, cache (acceleration time next visit)

 

Common client technology

1. Ajax
2. ActiveX
3. Flex - rich client, an architecture is interposed between the B / S, C / S
4. Extensions
5. silverlight

 

40 web server technology

Core functions:

1. Processing client requests (HTTP)
2. Response to a request sent by the client:
3. An intermediary between the client and the database: The client sends a data request to the server, the server calls the database; then the data in the database server back to the client
   • Architecture Layer 3: C - S - D
   • N layer Framework: a three-layer architecture includes a core architecture has increased mainly the rear end, as follows:

• • 1. web front-end server: only responsible for forwarding HTTP requests, is not responsible for access to the database, business logic processing
  • 2. Application server: the core business logic, and database and dealing;

 

Common web server technology

Apache: applies to any platform; IIS :( ​​applies to Microsoft); Tomcat; 

Application Server: J2EE servers; IIS server;

 

Common web server can only handle http requests and static resources, dynamic resource needs to complete the script engine.

Dynamic web server process has completed, after the server-side script engine is complete, return to standard HTML format to the client, general scripting engine, including: ASP, PHP, JSP, RUBY

 

Cluster environment

Definition: multiple servers gathered to perform the same kind of services (all in balance, failover), including the implementation of the following four:

1. Hardware cluster: use hardware complete, such as redware
2. OS cluster: a cluster to achieve through the operating system, part of a cluster-level software
3. Application server cluster:
4. Database cluster: a cluster database system directly, such as Oracle RAC

 

 

(WEB system testing - Deng Qiang)