1. IBM Certified WebSphere Application Server 8.5 Administrator
A course to get certified in 7 days
Karun Subramanian, ESIS Consulting LLC

2. WebSphere Application Server 8.5 Architecture
ESIS Consulting LLC
(C) ESIS Consulting LLC. All rights reserved

3. 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.
WebSphere 8.5 uses Java 1.6 (Java 6). But it also supports Java 7. You can use 'managesdk' tool to configure the Java version to be used.

4. 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 and
Workload 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

5. 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
Web Applications are packaged as WAR (Web Archive) files and deployed as WEB Modules

6. Describe Web Container Cont...

7. 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

8. 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

9. 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

10. 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
Message Driven Beans (MDBs) can automatically receive messages from a JMS Destination without 'polling' messages

11. 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
SIB can have the following Bus Members: Servers, Clusters or WebSphere MQ Servers
SIB creates a Messaging engine whenever a new member is added. If the member is a cluster, only one cluster member will have an active ME
Applications can exchange messages with other Applications using a ‘destination’ on the SIB
Web Services Gateway acts as a proxy for Web Services providing services like a)changing destination b)protocol transformation c)applying/removing message level security
Internet >DMZ >Web service gateway >application server

12. 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

13. 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
JNDI (Java Naming and Directory Interface) is built on top of cosNaming (Corba Naming Service)

14. 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
Web components use bean managed Transactions using the API provided by the product
Entity Beans use Container managed Transactions
Sessions Beans can either manage the transactions using the API or delegate to the Container

15. 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

16. 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
WAS can also control the cache outside of the Application Server, such as Web Server
Cache can be offloaded to disk (configurable)

17. 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

18. 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.
Dynamic Clusters: For complete life cycle management servers, Dynamic cluster can create or delete new Application Server instances.
For assisted life cycle management servers, Dynamic cluster can stop or stop Application Server members.

19. 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
You can log performance data (PMI data) using Tivoli Performance Viewer
ITCAM (IBM Tivoli Composite Application Manager) is an optional component that can be installed on WAS to collect additional metrics (typically deeper Metrics than that are provided by PMI)
For efficient logging, you can use HPEL (High Performance Extensible Logging). These logs can be viewed using logviewer command line tool
Request Metrics can be used to record response time of various subsystems within the WebSphere Application Server

20. 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
using 'dropins' method, you could place an application in a particular directory that will be automatically picked up and deployed

21. 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>
OSGi Admin Service injects configuration found in the server.xml file to Feature Manager which installs and starts the OSGi bundles.

22. 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)

23. 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)

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

25. Various topologies Standalone
Network Deployment - Nodes from same platform
Network Deployment - Nodes from various platforms
Flexible Management

26. Network Deployment

27. Flexible Management
Enables to manage multiple Application Servers or cells through one centralized Job Manager. Loosely coupled.
Job Manager dispatches work via Admin Agents

28. 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

29. 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

30. 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 Profile
Deployment Manager Profile
Custom Profile
Liberty Profile
Administrative Agent profile
Application Server Profile: Defines single stand alone Application Server that has built in Admin Console. Meant for Base and Express editions. Can be created in ND as well. It has once cell, one node and an an Application Server. Cell and Node are not relevant. There is NO Node Agent.
Deployment Manager profiles: Defines a Deployment Manager. It has one Cell, one Deployment Manager Node, One deployment manager with an Admin console. It has NO Application Servers. You can federate nodes built from existing Application Servers into the cell.
Custom Profile: Empty profile with one Node and no Application Servers meant to be federated into a Cell
Cell Profile: Consists of a Deployment Manager profile and an Application Server profile. DMGR and Application Server reside on the same physical Server. Meant for quick setup.
Administrative Agent profile: Provides a way to manage multiple standalone Application Server profiles in one centralized Admin console. The Administrative Agent communicates with all the standalone Application Servers
Job Manager Profile: Defines a Job Manager. Job Manager dispatches jobs for one more more Administrative Agents and one or more Deployment Managers in a Flexible Management topology
Secure proxy profile: This is a configuration only profile which is used to create Secure proxy server configuration elements. Once the profile is created, it can be exported from Deployment manager and imported on to a secure proxy server which is typically deployed in DMZ Network.

31. 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
Nodes that are grouped must be similar in resources and installed software. Deployment manager has no way of verifying this
Primarily used to restrict creation of Application Server Cluster members on certain Nodes (Example: When distributed and Z/os nodes are in the same cell)
A node can be member of more than one NodeGroup

32. 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.

33. 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)

34. 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
Static Clusters provide workload management. Dynamic clusters are part of 'Intelligent Management' environment where Cluster Members can be automatically stopped or started for workload management and/or high availability, In addition, Cluster members can be automatically created or deleted based on the workload.

35. 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)

36. 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
Both types of clustering offers their own advantages.

37. Traversing through a Client Request for a Web Application
Request originates from Client's browser (ex:
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

38. 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
Application Server returns the response to the Web Server which responds back to the client.

39. 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

40. 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
WebSphere System Management is based on JMX (Java Management Extensions). So, an application can be written to act as a JMX client and utilize the API provided by WebSphere to manage the environment.

41. 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.
When you create a Custom profile, a second cell named defaultcell will be created. But when you federate the node to the deployment manager (using addNode command), the defaultcell is removed and only one cell remains (the dmgrcell you created when you created the deployment manager profile)
For creating the profiles, one can use WebSphere Customization Toolbox or the 'manageprofiles' command

42. 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
Profiles home directory is typically installroot/profiles
The master config directory is typically installroot/profiles/dmgrprofile/config
The node config directory is typically installroot/profiles/profilename/config
syncNode command can be used to manually sync the configuration files

43. Configuration Repository Cont...
Important directories in repository (installroot/profiles/profilehome/config)
cells/cellname/
applications/applicationname- one directory for each application deployed
nodes/nodename - one directory for each node
nodes/nodename/servers/servername - one directory for each application server
nodes/nodename/nodeagent - directory for the node agent
clusters/clustername - one directory for each cluster
The configuration repository root is installroot/profiles/profileName/config
The configuration root contains the following additional important directories:
temp - temporary files created during configuration changes
backup - WAS backs up configuration files before applying changes
In standalone environment, there is no nodeagent or clusters directories