Portals Architecture Best Practices by suf46043

VIEWS: 40 PAGES: 21

									   February 2005




Portals:
Architecture &
Best Practices


    Greg Hinkle
Agenda
• Opportunities

• Challenges

• Best practices

• Strengths & Weaknesses




          Portals - Architecture & Best Practices   2
Opportunities
• User centric applications

• Personalized and customizable by users

• Aggregated views of many systems and content
  types




           Portals - Architecture & Best Practices   3
User centric
• Enterprise portals applications typically fall into
  two categories
   – Information integration portals provide access to data from
     many systems in an enterprise. They are oriented at
     visibility and should provide context and taxonomy. Search
     functionality is often the most difficult feature to implement
   – Process integration portals provide one place to accomplish
     human driven tasks that previously required accessing
     multiple systems.




              Portals - Architecture & Best Practices                 4
User centric (cont…)
• For task-based applications, focus on providing
  users with the best user interface for the tasks
  they accomplish
   – Provide only the information they need
   – Reduce steps to complete tasks

• For information applications, allow the user to
  rearrange and reconfigure portlets to their liking
   – Make sure portlets work anywhere with no dependencies
   – Provide search capabilities to find data across sytems




             Portals - Architecture & Best Practices          5
Personalization
• Create common content hierarchies and utilize
  CSS for formatting
   – CSS also allows for easier use of customizable look & feels

• Standardize user interface elements across
  portlets
   – Standardize form layouts, tabular data views and common
     user experiences such as search-list-detail
   – Reduces the “whiplash” of dealing with so many different
     types of information




             Portals - Architecture & Best Practices               6
Challenges
• Performance

• Data Consistency

• Communication

• Proprietary extensions

• Security

• Dynamic layout




             Portals - Architecture & Best Practices   7
Performance
• The nature of portlet applications creates situations
  where the portlets rendered on a single page may each
  make calls to retrieve the same content
• Caching is the primary solution to reducing database
  overhead, but be prepared for large shared caches in
  sites where many different content types are being
  displayed on a single page
• Using multi-threaded rendering helps latency, but
  maintains the same database load
• Resist the urge to use session or request scope caches
  where portlets depend on each other for data retrieval




             Portals - Architecture & Best Practices       8
Caching
• Four places at which to cache
   – A portlet cache stores the rendered portlet fragment
   – A fragment cache stores rendered fragments
   – A service cache stores the results of service tier calls
   – An entity cache stores results from the data access tier

• Caching impacts inter-portlet communication
   – Portlets may not be rendered in order or may be rendered
     simultaneously
   – Even if forking is turned off, portlets should support being
     rearranged
   – Only action lifecycle methods are guaranteed to run before
     rendering




               Portals - Architecture & Best Practices              9
Caching (cont…)
• Portlet cache
   – The portal specification defines time-expiration based
     portlet caching
       • WebSphere has customizable caching levels with custom keys
         and programmatic invalidation

       • WebLogic has per user, time-based caching and can’t be
         programmatically invalidated (a portlet cache is invalidated
         when an action is sent to it)


• Fragment cache
   – Stores generated fragments by customizable keys
   – Solutions such as OSCache




             Portals - Architecture & Best Practices                    10
Caching (cont…)
• Service cache
   – Utilize a custom cache or cache library
   – Use custom business logic to refresh as necessary

• Entity cache
   – Use the cache of your persistence layer such as Entity
     Bean caching or hibernate caching
   – One of the simplest to use




             Portals - Architecture & Best Practices          11
Communication
• Inter-portlet communication can be
  accomplished by setting application scope
  session variables

• Portlets should gracefully handle when those
  variables are not available

• Information for render can be passed to JSPs in
  the request

• Avoid situations where a portlet utilizes the
  result of an action execution on a portlet other
  than itself

           Portals - Architecture & Best Practices   12
Portlet extensions
• Many Portal servers provide proprietary
  extensions to the JSR-168 development model
   – Simplified development with provided tools
   – Enhanced inter-portlet communication such as event
     listeners
   – Complex, visual page flow management
   – Separation of view and controller with backing JSPs (model-
     2 for portlets)

• These extensions are not portable to other
  servers and often require the use of provided
  development tools



             Portals - Architecture & Best Practices               13
Security
• Portlet access security is simply an extension of
  web application security with the same
  limitations
• Basic user portlet access can be controlled with
  isUserInRole()
• Data access control can be accomplished if the
  service API is built to support security checks
• End-to-end security may be best implemented
  with technologies such as Kerberos




           Portals - Architecture & Best Practices    14
Dynamic layout
• A single portlet may be displayed twice on the
  same page

• For these types of portlets, beware of request
  parameters and JavaScript
   – Use the namespace tag to differentiate document ids

• Portlet scope is safe and not shared between
  two portlets on the same page




             Portals - Architecture & Best Practices       15
Best practices
• Utilize JSPs for content display as with Model-2

PortletContext portletContext = getPortletContext();
PortletRequestDispatcher prd =
   PortletContext.getRequestDispatcher(“/jsp/PortletView.jsp”);
Prd.include(request,response);

• Use Portlet JSP tags for forms

<portlet:actionURL var=“submitUrl”>
  <portlet:param name=“action” value=“save”/>
  <portlet:param name=“contentId” value=“<%=contendId%>”/>
</portlet:actionURL>
<form action=“<%=submitUrl%>”>
   …
</form>


              Portals - Architecture & Best Practices             16
Best practices (cont…)
• Use a custom print mode to support simplified
  layouts for printing portlet contents

• Utilize web-app context parameters for
  initialization information common to multiple
  portlets

• Uses preferences to store user configurations
  of a portlet

PortletPreferences prefs = request.getPreferences();
prefs.getValue(“RSS_URL”, “http://my.rss.com/rss”);




              Portals - Architecture & Best Practices   17
Best practices (cont…)
• Use createRenderURL() and createActionURL()
  to create links

• Use getContextPath() to link to images

• Only update state in action calls

• Group portlets that operate on the same data
  into a single portlet application to allow them to
  share initialization parameters




           Portals - Architecture & Best Practices     18
Portal strengths
• Replacing homegrown intranet applications for
  employees that were already portal-like

• Providing customizable user experiences by
  allowing application interfaces to be assembled
  according to their use

• A common platform that when implemented by
  more application providers will simplify
  development of complex systems




           Portals - Architecture & Best Practices   19
Portal weaknesses
• Using many complex Portlets can often cause
  performance issues due to the many round-trip and
  separate data retrievals
• Creating tight integration between applications built with
  varying technologies
• No provisions for detailed, data-level security within
  integrated applications
• The component like construction of portlets can lead to
  poor and inconsistent user interfaces
• Lacks the development benefits of the mature web
  frameworks such as Struts and WebWork (configurable
  page flow, validation, form management)



              Portals - Architecture & Best Practices          20
         February 2005




    Questions?



   Download the slides for this
presentation and Part 1 – Portals:
       Background from:
   http://chariotsolutions.com

								
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