WebLogic introduction and several basic concepts

BEA WebLogic is a Java application server used to develop, integrate, deploy, and manage large-scale distributed Web applications, network applications, and databases. Introduce the dynamic functions of Java and the security of Java Enterprise standards into the development, integration, deployment and management of large-scale network applications.
BEA WebLogic Server has the performance, scalability, and high availability required to handle critical web application system problems. In combination with Bea Weblogic commerce servertm, BEA WebLogic Server provides a complete solution for deploying an adaptive and personalized e-commerce application system.
BEA WebLogic Server has the features and advantages required to develop and deploy e-commerce web application systems for key tasks, including:
1) leading standards
Comprehensive support for various standards in the industry, including EJB, JSB, JMS, JDBC, XML, and WML, simplifies the Implementation of Web application systems and protects investment, it also makes development based on standard solutions easier.

2) unlimited scalability
BEA WebLogic Server is well known in the industry for its highly scalable architecture system, including client connection sharing, resource pooling, dynamic web pages, and EJB component clusters.

3) Rapid Development
With support for EJB and JSP, and BEA WebLogic Server's servlet component architecture system, you can accelerate the Market Projection speed. These open standards work with webgain studio to simplify development and leverage existing skills to quickly deploy application systems.

4) more flexible deployment
BEA WebLogic Server is characterized by its close integration with leading databases, operating systems, and web servers.

5) Reliability of key tasks
Its Fault Tolerance, system management, and security performance have been verified in the critical task environment of global Log service.

6) Architecture
BEA WebLogic Server is specially developed for enterprise e-commerce application systems. Enterprise e-commerce application systems need to be developed quickly, and the server-side components must have good flexibility and security. At the same time, they must support the expansion, performance, and high availability required by key services. BEA WebLogic Server simplifies the development of portable and scalable application systems and provides rich interoperability for other application systems and systems.

BEA WebLogic Server has the highest scalability and availability with its excellent cluster technology. BEA WebLogic Server implements both webpage clusters and EJB component clusters without any dedicated hardware or operating system support. Webpage clusters can achieve transparent replication, load balancing, and content error tolerance, such as web Shopping Cart. Component clusters handle complex replication, load balancing, and error tolerance of EJB components, and recovery of State objects (such as EJB entities. Whether it is a web cluster or a component cluster, the scalability and availability required by the e-Sub-commerce solution are crucial. Shared Client/Server and database connections, data caching, and ejbs all enhance performance. This is not available in other web application systems.

WebLogic application server has the following basic concepts:

Domain:A domain is a logical concept used to organize and manage a series of application server instances, that is, the server to be explained below. the domain is the largest concept in the WebLogic application server. When the WebLogic application server is started, it starts with a certain domain. It has a central configuration file called config. XML.

A domain is the basic administration unit for WebLogic Server instances (servers) that is represented in its own configuration file (config. XML ). A domain consists of one or more servers (and their associated resources) that you manage with a single administration server.

Cluster:It is also a logical concept used to group server instances for the same purpose. A domain can have multiple families.

A cluster is a deployment in which multiple WebLogic Server instances (servers) run simultaneously and work together to provide increased scalability and reliability. A cluster appears to clients to be a single Weblogic server instance. the servers that constitute a cluster can run on the same machine, or be located on different machines.

MACHINE:A machine is a physical concept that represents a real machine running the WebLogic application server, including its IP address and other information. A domain can contain multiple machines. (Can a single machine belong to different domains ?)

A machine is the logical representation of the computer that hosts one or more WebLogic Server instances (servers ). webLogic Server uses configured machine names to determine the optimum server in a cluster to which certain tasks, such as HTTP session replication, are delegated. the Administration Server uses the machine definition in conjunction with the Node Manager application to start remote servers.

Server:Server, that is, an application server instance, which is used to deploy and run various J2EE applications. You can also configure various service programs. It is the basic service unit of WebLogic application server. A WebLogic domain generally has one management server and multiple managed servers. That is, the two concepts we will talk about below.

A server is an instance of Weblogic server that runs in its own Java Virtual Machine (JVM) and has its own configuration. each WebLogic Server domain must have one server that acts as the Administration Server. in a typical production environment, the Administration Server is where the Administration Console is run and used to perform administrative tasks. by default, the Administration Server is called myserver. A typical production environment may also have one or more managed servers, which are instances of Weblogic server used to host enterprise applications.

Administrative Server:The Management Server is used to manage the central point of the configuration domain. Generally, the management server does not deploy applications, it is used to centrally manage, configure, monitor managed servers, and deploy applications on managed servers. A domain has a management server.

Managed Server:Managed servers are used to deploy and run various applications. One or more managed servers in a domain.

Node Manager:The Node Manager is a separate background program that runs on the managed server machine. It is used to remotely start and stop the server.