A course to get certified in 7 daysKarun Subramanian, ESIS Consulting LLC

IBM Certified WebSphere Application Server 8.5

Administrator

WebSphere Application Server 8.5 Architecture

ESIS Consulting LLC

(C) ESIS Consulting LLC. All rights reserved

Real Quick: What is WebSphere?

• Family of Software products from IBM• WebSphere Application Server, being the

most popular, is an implementation of JEE (Java Platform Enterprise Edition) specification

• Extends JEE by providing several features and Services

• Is the runtime environment for your JEE Applications

• Equivalent products from other Vendors are Oracle WebLogic, JBOSS,Oracle GlassFish

* WebSphere Application Server and WAS are interchangeably used in this presentation.

What's inside WAS 8.5 ?WAS 8.5 Core components

Web Container Runs Web Applications

EJB Container Runs EJB Applications (provides threading and transaction support)

Messaging Engine Provides robust messaging infrastructure

Web Services Engine Runs Web Services

Naming and Directory Provides JNDI infrastructure that includes naming servers

Transactions Provides Support for Transactions (XA)

Security Infrastructure Robust security (Administrative, Application and Java2 security)

Performance Infrastructure Tivoli Performance Viewer, Advisor and PMI

High Availability andWorkload Management

Clustering, Dynamic Clustering based on weight and load, On demand Routing

Admin Application Web Interface (Admin Console) and wsadmin (Scripting)

JCA Services Provides connectivity to backend systems

Describe Web Container

• Runs JEE compliant Web Applications that contain Servlets,JSPs and static HTML pages

• Handles HTTP Sessions• Runs Portlets (using a Portlet Container) and

SIP (Session Initiation Protocol) Applications (using a SIP container)

• Provides Transport Chain that includes TCP Inbound Channel, HTTP inbound channel and Web Container Channel

• There is one Web Container per Application Server

Describe Web Container Cont...

Describe EJB Container

• Provides runtime for EJBs (Enterprise Java Beans)

• EJBs handle business logic and can manage data access (Entity EJBs)

• EJB Container provides threading and transaction support

• EJBs are packaged as JAR files (Java archive) and deployed as EJB modules

Clients

Clients can be one of the following:• Application Clients: Run in a JEE compliant

Client container (installed separately from the Application Server). launchClient tool can be used to start the clients

• Web Clients: Most common. This is typically the Web Browser

• Web Services client• Admin Client: wsadmin and Admin Console

Web Application

Describe Web Services Infrastructure

• Application Server acts as both Web Services client and Server

• Web Services are reusable Web Applications that can be described,published,discovered and invoked over Network. They implement SOA (Service Oriented Architecture)

• Under the cover, Web Service operations are executed as Servlets

Describe Messaging Infrastructure

• Full support for JMS (Java Messaging Service)

• Message Providers: Default Messaging Provider,WebSphere MQ Provider, Generic JMS Provider

• Providers use JCA (Java Connector Architecture) to communicate with JMS destinations (Queues or Topics)

• Concept of inbuilt JMS Server has been replaced since Version 6

Describe Messaging Infrastructure Cont..

Service Integration Bus:• Integrated Communication infrastructure for

Messaging and SOA Applications• Contains Messaging Engines and acts as a

JMS Provider• Contains destinations (Web Service

endpoints, Messaging Queues or Topics)• Contains a Message Store• You can make an external Web Service

available at a service destination

Describe Data Access

• WAS uses JCA to access external Data Sources such as EIS, RDBMS

• JCA requires a Resource Adapter to be provided by the EIS Vendor

• Resource Adapter is a system level driver that enables WAS to communicate with the Data Provider

• Resource Adapters are plugged into WAS• WAS provides pre defined RDBMS

Resource Adapter

Describe Naming and Directory

• Each Application Server runs a JNDI Naming Service which enables Applications to register and look up resources

• WAS provides distributed Name Space for scalability

• Objects are bound in hierarchical structure in Name Space

• dumpNameSpace tool exports the Name space for troubleshooting

Describe Transactions Infrastructure

• Transactions are multiple operations on resources co ordinated as one unit of work

• Transaction Manager, part of WAS handles transactions. Also participates in other transaction managers on Global Transactions

• Operations are rolled back in case of failure• Transactions can be container managed or

bean managed• Transactions are tracked through logs

(tranlog) for rolling back purposes

Other Services provided by WAS

• Java Mail• Resource References: Enables to specify

logical names in deployment descriptors that bind to physical resources. Logical names are then accessible through JNDI lookups

• Scheduler: Runs tasks at specified times or intervals. Tasks can be prioritized

• Asynchronous Beans: Enables a resource intensive task to be run as multiple tasks

• Startup Beans: Runs your code on WAS startup or shutdown

Other Services provided by WAS Cont...

• Dynamic Cache: Greatly improves performance of Web Applications. Can replicate Cache among clusters

• Object Pools: Improves performance by reducing object instantiation time

• Activity Sessions: Enables grouping of operations on multiple one-phase commit resources

• Internationalization: Enables application to process information based on the geographical location of the client

Describe Security Infrastructure

• Solid security at various tiers in the architecture (end to end)

• Support for federated user repositories and Security domains

• Support for strong encryption (SSLv3/TLS)• Efficient SSL Certificate Management• Supports Java 2 Application level security

Describe High Availability Infrastructure

• Support for Application Server Clusters• Data among the cluster members are

replicated either using memory-to-memory replication or using Database

• HA Manager, which runs in each Application Server provides the framework for communication among cluster members.

• Dynamic Clusters: Balance workload among cluster members based on the performance, dynamically. Can expand or contract.

Describe Performance Infrastructure

• PMI (Performance Management Infrastructure) makes metrics available through Management Beans

• Tivoli Performance Viewer can be used to view current activity and summary reports via WAS Admin Console

• Tivoli Performance Viewer Advisor provides advice to tune inefficient settings

• Performance and Diagnostic Advisor prints warning messages in SystemOut.log about inefficient settings

Liberty Profile

A profile defines the runtime environment• Is a lightweight Application Serving

environment mostly used in Development environments

• Uses OSGI framework (Pluggable modules)• Supports Web Applications, OSGI

Applications and JPA• Very fast startup• Deploy applications using 'dropins' or by

updating configuration

Liberty Profile Cont...

• Comprises of JVM, Liberty Kernel and Features (OSGi bundles)

• server.xml is the server configuration file• Updates to configuration file is read by File

Monitor Service. Features are loaded dynamically.

• Features to be loaded are specified in the server.xml

<server> <featureManager> <feature>servlet-3.0</feature> </featureManager></server>

Liberty Profile Security

• Security as per Servlet 3.0 specification• Web Container delegates security check to

WebSecurity Collaborator which talks to Authentication Service first to create 'subject' and then to authorization service to perform authorization check

• You can use the quickStartSecurity element in server.xml to quickly grant access to one user

• Auth Constraints can be defined in the deployment descriptor (web.xml)

Full Profile

• Meant for Production environments (can be used in Development a well)

• Full blown product with all the bells and whistles

• Main components: Application Servers, Clusters, Resources, Administration

• Supports the three-tier architecture (Presentation, Business Logic, Data/ERP)

Topologies

Various components in any Topology:• Application Servers• Application Server Clusters• Nodes• Node Agents• Deployment Manager• Web Servers• Profiles• Cell

Various topologies

• Standalone• Network Deployment - Nodes from same

platform• Network Deployment - Nodes from various

platforms• Flexible Management

http://pic.dhe.ibm.com/infocenter/wasinfo/v8r5/index.jsp?topic=/com.ibm.websphere.nd.multiplatform.doc/ae/tagt_jobmgr_install_im.html

Network Deployment

Flexible Management

Describe components in a topology

Cell

• A logical grouping of related components such as Application Servers, Nodes, Core groups and Web Servers

• Is NOT an Operating System process• Manages the central configuration repository

(XML Files)• A cell can contain nodes from various

physical Servers• Cluster members must belong to the same

cell

Describe components in a topology

Deployment Manager

• Provides single point of Administration for all the components in a Cell

• Each cell contains one Deployment Manager• Hosts the Administration Console• Is an Administrative Agent• Is created when a deployment manager

profile is created• There is a dmgr node and dmgr application

server that runs the dmgr application

Describe components in a topology

Profile

• After the product installation, you need to create one or more profiles to define the runtime

• Product files are shared among profiles• Various types of profiles

Application Server ProfileDeployment Manager ProfileCustom ProfileLiberty ProfileAdministrative Agent profile

Describe components in a topology

Nodes and Node Groups

• Node is a grouping of managed or unmanaged Servers. Usually a physical computer system

• If it hosts a WebSphere Application Server and federated into a ND environment, it is a managed node

• Node Group is a collection of managed nodes• Application Server clusters must belong to the

same Node group• Node Groups are optional. By default all nodes

belong to DefaultNodeGroup

Describe components in a topology

Node Agent

• Represents a Node• Only present on Network Deployment• Monitors Application Servers on the Node• Routes Administrative requests to

Application Servers• Once stopped, can only be started using

'startNode' command• Once stated, can be restarted from Admin

Console.

Describe components in a topology

Application Server

• Is the JVM that runs the user Application• The core component in any topology• Can be part of Application Server Cluster• With BASE install, Application Server named

server1 is automatically created. This server can be managed using Admin Console

• You can create additional Servers but need to configure an Administrative agent if you want to centrally manage them (otherwise, use command line or individual Admin Consoles)

Describe components in a topology

Application Server Cluster

• Group of Application Servers that helps distribute the workload and provides high availability for the Applications deployed

• When application is deployed on a cluster, it is automatically installed on all cluster members

• A node group defines the boundary for a cluster

• Two types of clusters: Static and Dynamic

Describe components in a topology

Web Server

• Receives HTTP requests from clients (typically, browsers), forwards the request to WebSphere Application Server, obtains response and sends it back to the client

• Popular Web Servers: Apache, IBM HTTP Server, IIS

• WebServer Plugin, a piece of software that enables Web Servers route requests to WAS

• You must create a Web Server definition on WAS Admin console to manage the Web Server (Managment capabilities depends on the type of the Web Server)

Describe components in a topology

Vertical and Horizontal clustering

• Vertical Clustering is where multiple Application Servers run on the same Physical Server. This provides process level HA and Workload management

• Horizontal clustering is where multiple application servers run on multiple Physical Servers. This provides Server level HA and workload management

• It is common to have mixed clustering in production environments

Traversing through a Client Request for a Web Application

• Request originates from Client's browser (ex: www.emportal.com/login)

• Client's computer resolves the URL to an IP address and sends a HTTP Request

• In production environments, typically a hardware load balancer (such as F5) is the first point of entry (there may be firewalls and edge components prior to the load balancer)

• The load balancer sprays requests to set of Web Servers. This Web Server can be in a DMZ network

Traversing through a Client Request for a Web Application Cont...

• You can have a caching proxy between the Web Server and Application Server. There can also be an external cache server (such as Akamai before the Web Server)

• There can also be a security server (such as Siteminder) that integrates with the Web server

• The Application Server processes the request and can communicate with a backend server such as relational database server or Mainframe

Administration Tools

Available Administration tools:• Integrated Solutions Console (formerly Admin

Console) - web based Application that can be used to manage a Cell or standalone Application Server

• wsadmin - jython based scripting framework that can be used to automate several Administrative tasks

• WebSphere customization Tool Box - tools for customizing the environment that includes Web server plugin configuration tool and Profile Management Tool

Administration Tools Cont..

• Command Line Utilities - several commands provided with the product

• Administrative applications - custom developed applications utilizing JMX

• ANT scripts - you can write ANT scripts to build and deploy applications on WebSphere

Typical System Management Flow

1. Install the product using IBM Installation Manager

2. For Standalone environment (No clustering), create Application Server Profile. You can now manage the environment

3. For Distributed Server environment, you create a Deployment Manager profile which will create a Cell and Deployment manager node. You would then create a Custom Profile or an Application Server profile and federate the Node (that would be created when you create the profile) to the cell.

Configuration Repository

• Deployment Manager maintains the master configuration (set of xml files in local File System)

• Each Node has a copy of relevant configuration files

• Changes to Master configuration files are synced with all the nodes

• Changes made to the Node configuration files directly will be overwritten with master copy when the node sync occurs

Configuration Repository Cont...

Important directories in repository (installroot/profiles/profilehome/config)

• cells/cellname/o applications/applicationname- one directory for each

application deployedo nodes/nodename - one directory for each nodeo nodes/nodename/servers/servername - one

directory for each application servero nodes/nodename/nodeagent - directory for the node

agento clusters/clustername - one directory for each cluster