WebLogic Domain

Agenda

• Domain• Overview of Weblogic Server Domain• Admin Server• Managed Server• Resources and Services• Standalone v/s Clustered Managed Servers• Nodemanager• Clusters

Domain

• A domain consists of one or more WebLogic Server instances which are managed by a Admin Server

• A domain can contain:1. Admin Server

2. Managed Server

3. Cluster

4. Resources and Services etc. .

• Modes of Domain Creation are :1. Development Mode2. Production Mode

• Common Domain Types are:

1. Domain with Managed Servers

2. Standalone Server Domain

OVERVIEW OF WEBLOGIC SERVER DOMAINS

Admin Server

Resources and Services

Resources and Services

Resources and Services

Managed Server

Managed Server

Managed Server

Resources and Services

Managed Server

Managed Server

Managed Server

Cluster

ADMIN SERVER•The Administration Server serves as a central location from which to manage and monitor all resources in a domain.•It maintains the domain's configuration documents and distributes changes in the configuration documents to Managed Servers.

Roles of Admin Server:•Act as a central control entity to configure the entire domain. That is, helping in configuring Managed servers, clusters etc..

What happens if Admin Server Fails ?

• Does not affect the operation of Managed Servers in the domain

• Managed Servers and Clusters configured will continue to run

• Load Balancing and Fail Over remains Available

MANAGED SERVERIn a domain, server instances other than the Administration Server are referred to as Managed Servers

Functionality of Managed Server:•Helps in deploying Applications.•One or More Managed servers can be grouped to form clusters.

RESOURCES AND SERVICESA domain contains resources and services needed by Managed Servers and applications deployed in the domain

Examples:Application components, such as Web Applications, J2EE Connectors and Enterprise ApplicationsJDBC connection poolsJMS servers

STANDALONE V/S CLUSTERED MANAGED SERVER

Stand Alone MS Clustered MS

Used in Development Environment Used in Production Environments

No Load Balancing or Fail Over Mechanisms

Load Balancing and Fail Over Mechanisms are present

SERVER LIFE CYCLE

NODEMANAGER• NodeManager is a java utility that allows you to perform

common operations tasks for a managed server.• Runs as a separate process from weblogic server.• Useful in production environments where the weblogic

managed servers are distributed across multiple machines

NODE MANAGER CAPABILITIES

• Node Manager enables you to perform these tasks:

1. Start and stop remote Managed Servers.2. Monitor the self-reported health of Managed Servers

and automatically kill server instances whose health state is "failed".

3. Automatically restart Managed Servers that have the "failed" health state, or have shut down unexpectedly due to a system crash or reboot.

START MANAGED SERVER

SHUTDOWN MANAGED SERVER

Stop a managed server.Shutdown a failed managed server

RESTART MANAGED SERVER

Number of attemptsTime-Span.

WHAT HAPPENS IF THE NODE MANAGER FAILS??

• Do not shut down the managed server which the node manager was monitoring.

• Node manager must be restarted either by the operating system or manually

Flow Diagram of Domain InstallationStartStart

Choose to create new

domain

Choose to create new

domain

Select Product components or

template

Select Product components or

template

Specify username and password for Admin Server

Specify username and password for Admin Server

Select Product components or

template

Select Product components or

template

Customize environments or services ?

Customize environments or services ?

Specify and create domain

Specify and create domain

DoneDone

Customize EnvironmentCustomize Environment

Configure Admin Server

Configure Manage Server, Cluster and machines

Assign Servers to cluster and machines

Customize ServiceCustomize Service

Configure and test DB connectivity

Load DB

Change JMS File StoreYES

Review SettingsReview Settings

No

CLUSTER

CLUSTER

•Multiple Weblogic server instances running simultaneously to provide scalability and reliability•Cluster capacity can be increased dynamically by adding machines to cluster (Same version of Weblogic)

Benefits Of Clustering

• Scalability• High-Availability

Key Capabilities of a Cluster

• Application Failover• Load Balancing

Application Failover

Failover means “an application component doing a particular “job”—some set of processing tasks—becomes unavailable for any reason”

Copy of failed object

Failed Object

Copy

Available?

YES (mandatory)

Information should be made available to all other objects and program that handles failover.Location and operational status of all object

Object taking over an interrupted job knows how much of the job was completed before the first object failed

Picking up from where it had failed

Load Balancing•Load balancing is the even distribution of jobs and associated communications across the computing and networking resources in your environmentFor load balancing to occur:

•There must be multiple copies of an object that can do a particular job.

• Information about the location and operational status of all objects must be available.

Load Balancer

Application Instance 1

Application Instance 2

Application Instance 3