What is a Portlet? Explain its capabilities.

Portlets are UI components that are pluggable and are managed, displayed in a web portal. Markup code fragments are produced by the portlets which are aggregated into a portal page. A portlet resembles an application that is web based and is hosted in a portal. Email, discussion forums, news, blogs, weather reports are some of the examples of portlets. 

Explain Portal architecture.

The core implementation of the portal is UI, hosted by a Portal server. The HTTP requests, HTML responses, and returning appropriate portal pages are handled by the Portal UI. Enterprise Web application also can be handled by the Portal Server.

The portal architecture has the following:

Automaton Server: This server performs the management of job scheduling and implementation of a portal. It accesses all remote crawlers and profile services retrieved and stored from a remote database.

Image Server: This server hosts images and other web page content used by web services and a portal. With this configuration, large static files are to be sent directly to the browser without portal server impacts.

Search Server: This server indexes and searches all the information, applications, communities, documents, web sites through portal.

Collaboration Server: Web content publication and management for portals and web applications are supported by this server. Its functionality can be accessed by a remote web services through Enterprise Web Development kit.

Content Server: Publication and management of web content for portals and web applications along with form based publishing, branding, templates, content expiration is allowed by this server.

Authentication Server: This server handles the portal authentication for users and remote services can be accessed through EDK.

Remote Servers: Web services written using the EDK are hosted by remote servers. The servers can be in different countries, on different platforms and domains. 

What is PortletSession interface?

User identification across many requests and transient information storage about the user is processed by PortletSession interace. One PortletSession is created per portlet application per client.

The PortletSession interface provides a way to identify a user across more than one request and to store transient information about that user.

The storing of information is defined in two scopes- APPLICATION_SCOPE and PORTLET_SCOPE.

APPLICATION_SCOPE: All the objects in the session are available to all portlets,servlets, JSPs of the same portlet application, by using APPLICATION_SCOPE.

PORTLET_SCOPE: All the objects in the session are available to the portlet during the requests for the same portlet window. The attributes persisted in the PORTLET_SCOPE are not protected from other web components. 

What is PortletContext interface?

The portlet view of the portlet container is defined by PortletContext. It allows the availability of resources to the portlet. Using this context, the portlet log can be accessed and URL references to resources can be obtained. There is always only one context per portlet application per JVM. 

Why portals?

The following are the reasons to use portals:

Unified way of presenting information from diverse sources.

Services like email, news, infotainment, stock prices and other features are offered by portals.

Provides consistent look and feel for enterprise. Eg. MSN, Google sites. 

Function-based portals

Horizontal Portals:
These are the portals are of type general interest. Yahoo!,Lycos,AOL,Freeserve,Sympatico are examples of horizontal portals.

Vertical Portals
They provide a gateway to the information pertaining to a specific industry such as insurance, banking, finance, automobile, telecom etc.

User-Based Portals

B2B Portals
The enterprises extend to suppliers and partners by using B2B portals.

B2C Portals
The enterprises extend to customers for ordering, billing, services by using B2C portals.

B2E Portals
The enterprise knowledge base integration and related applications into user customizable environment is done with B2E portals. This environment is like one stop shop. 

 Basic Interview Question:-

1. What is the difference between Application Server and Portal Server ?
   
   Application servers extend the ability of a Web server to handle Web application requests, and enables a server to generate a dynamic, customized response to a client request. A portal server extends the application server by providing a portlet container that can run portlets and to create portal a website that provides users with a single point of access to Web-based resources by aggregating those resources in one place.
2. What are the steps involved in deploying themes and skins in a clustered production websphere portal environment ?
   
   Export the WebSphere wps.ear (Portal EAR) using wsadmin.
   Use EarExpander tool to expand the exported wps.ear file.
   Copy the updated themes and skins into ../themes/html, ../skins/html folder.
   Use EarExpander tool to collapse the EAR directory into an EAR file.
   Use wsadmin to update the wps.ear to complete the deployment of updated themes and skins.
3. What changes needs to be done to view changes to your theme and skins JSPs without restarting the portal server ?
   
   You need to enable automatic JSP loading by setting reloadingEnable property to true in ibm-web-ext.xmi file of the wps.ear.
4. What are the 3 different ways of installing a portlet application in WebSphere Portal ?
   
   Install a portlet using the portal administration page using Web Modules portlet.
   Install a portlet using xmlaccess tool.
   Pre-deploy a portlet as a standard EAR by installing the portlet WAR file in WAS console and then registering the portlet using xmlaccess.
5. What is the purpose of XMLAccess configuration file Export.xml & ExportRelease.xml ? What is the difference ? & When will you use one over the other ?
   
   Export.xml exports the complete portal configuration and useful when transferring configurations between development installations.
   ExportRelease.xml exports the complete portal configuration from the release domain as required by the portal ReleaseBuilder tool and useful when tranaferring different release configurations between staging and production environments.
6. List me the steps involved in building a release in WebSphere Portal ?
   
   If you have a completely new installation of the staging server and the production server:
   
   Install the staging server, then install the production server.
   Develop a release on the staging server.
   Build the release on the staging server.
   Empty portal contents on the production server by running the WPSconfig.sh|bat action-empty-portal task.
   Import that release onto the production server. Refer to Transferring a complete configuration for information.
   
   If you already have a production server without a staging system:
   
   Export the release of your production server.
   Install an empty staging server using one of the following two methods:
   Install the staging server with the flag -W emptyPortal.active=True.
   After installing and configuring the staging server, run the WPSconfig.sh|bat action-empty-portal task.
   Import the production release onto the staging server. Refer to Transferring a complete configuration for information.
   Develop and build a new release on the staging server.
   Export that new release from the staging server.
   Use ReleaseBuilder to generate the differential between the two releases.
   Import the differential onto the production server.
7. What is the purpose of ReleaseBuilder tool in WebSphere Portal ?
   
   ReleaseBuilder enables management of release configurations independent of user configurations and used during staging of follow-on releases of WebSphere portals, configurations, and artifacts need to be moved between systems.
8. What are the steps involved in editing WebSPhere Member Manager (wmm.xml) files on a federated node ?
   
   On the primary node of the WebSphere Portal cluster, check out the files using ./WPSconfig.sh check-out-wmm-cfg-files-from-dmgr task.
   Make any changes to the Member Manager files. The files can be edited in the portal_server_root/wmm directory on the WebSphere Portal node.
   When you have completed your changes, check the files back in using ./WPSconfig.sh check-in-wmm-cfg-files-to-dmgr.
9. How to change the default portal URI /wps/portal after installation ?
   
   Set the property WpsContextRoot to the new URI and run ./WPSConfig.sh modify-servlet-path task.
10. List different types of user registry supported by WebSphere Portal ?
    
    LDAP (includes LDAP with an optional database user registry).
    Database user registry.
    Custom User registry, (non-LDAP, non-database).
11. What is LDAP realm support and why would I want to use it?
    
    A Realm allows you to group users from one or more LDAP trees of one user registry and expose them as a coherent user population to WebSphere Portal; this is also referred to as horizontal partitioning. Realms allow a flexible user management with various configuration options; for example, you can combine principals from one or more corporate LDAP tree. A realm must be mapped to a Virtual Portal to allow the realm's defined user population to login to the Virtual Portal.
12. What is an Application group and why would I want to use it ?
    
    Application groups is a concept that allows you to define user groups within the database user registry with members (users or groups) contained in the LDAP user registry you configured. The benefit of application groups is that you can create Groups that are only used in WebSphere Portal particularly in scenarios where there is Read-only LDAP or special group setup specific to the portal.
13. What are the two methods to install the empty staging WebSphere portal server ?
    
    Empty portal contents on the staging server by running the ./WPSconfig.sh action-empty-portal.
    Install portal with the ./install.sh -W emptyPortal.active="True" option.
14. How do you stop portal traffic to the node being upgraded in 24x7 cluster upgrade process ?
    
    Locate the cluster member being upgraded, and change the value in the Configured weight column from a value to zero and make sure the plugin config information is propagated to webserver to stop traffic.
15. How to set limits on searches for users and groups ?
    
    Setting a maximum number of search results maximumSearchResults="200"
    in wmm.xml
16. What portal resources are scoped for virtual portal ?
    
    Portal pages.
    Portlet instances.
    Portal Search Engine search services and search collections. This includes the search content sources.
17. What portal resources can't be seperated for virual portal ?
    
    Themes and skins.
    Vault segments and vault slots.
    Supported clients and markups.
    Composite applications and templates.
    Policies.
18. How do you enable temporary and extended trace logging for WebSphere Portal ?
    
    Temporary traces can be set for a temporary period by using the administration portlet Enable Tracing or the IBM WebSphere Application Server administrative console and also using the Enable Tracing portlet in the portal administration page.
    
    To enable extended trace settings for a longer period of time, that is, for more than one session, switch them on in the WebSphere Application Server configuration, save the updates and restart the portal server.
19. What are the different states of the syndication process ?
    
    Idle: No syndication is occurring.
    Pending: A request has been made to the syndicator, but it has yet to initiate a request to the syndication application.
    Queued: The syndicator has sent a request to the syndication application, but syndication is not yet active.
    Active: Syndication is occurring between the syndicator and subscriber.
    Disabled: Syndication is currently disabled.
20. What are the two types of rendering portlets ?
    
    Local rendering portlet and Remote rendering portlet.