Cloud Tech 101

“It went up, it went up to the cloud”
“You can’t get it down from the cloud?”

“Nobody understands the cloud, it’s a ****ing mystery.”

... says Cameron Diaz ! Well, here is something that should help !




[Update]: Here is the link to a more detailed article : http://mashable.com/2015/04/02/public-private-hybrid-cloud/?utm_cid=mash-com-Tw-main-link

Source: http://www.intel.in/content/www/in/en/cloud-computing/cloud-computing-innovation-infographic.html

Mobile App Review: CultureAlley's English App

Listed by Economic Times as one of the 15 hot startups to watch out for in 2015, CultureAlley brings to the market a unique B2C proposition - A Hindi based English Learning App.

With well crafted modules starting from spelling names to incrementally building expertise in grammar and vocabulary, English App is a class apart from several other Edutainment  based mobile apps.

Strategic Analysis: With only 10% of the Indian population currently speaking English and a growing need for innovative language learning techniques,CultureAlley's English App fits right into the space of making learning entertaining. The app begins with the user spelling his or her name and then carefully leads the user through various levels of learning English. Several other startups in the space like Rosetta Stone, LearnEnglish Grammar, Duolingo etc. each come with their own unique points of differentiation in the edu-tech space, but English App has a competitive edge ,having incorporated several unique techniques together.

PODs: Several unique feature that make the English App fun to use are :

• Gamification: Well designed games like Cutting Chai are conceptually right on the spot given the target audience and not only help keep the user engaged but also make learning fun.
• Superior UI/UX: The app is very user friendly and also includes commonly used English words in Hindi ("continue","next") etc. The color tone is fresh and as the lessons progress, navigation and screen flow is seamless.
• FB/Wiki Integration: The app allows the user to link his/her FB newsfeed and get translation highlights for the key words. This inclusion of the social aspect is one of the most attractive and innovative features of the app.
• Audio-Visuals: It sure helps to hear each word out loud.And the app scores rather well there. Each new module has some crisp AVs that make things easy for the learner.
• Help at Hand and Tutor Notifications: Timely assignments from the tutor and online chat facility keep the learner engaged and motivated.   

Revenue Model: Freemium + Ads

Started in Dec 2014, English App is well loved by the investors and by the users as well.

Types of Mobile Applications: Difference between Native, Hybrid and Web applications

There are many contradictory views on the various types of mobile applications that can be developed for mobile devices

Mainly most mobile applications can be-

1) Native Mobile Applications :
Completely coded using the sdk of the various platforms (like Android and iOS).
The language is used to implement both UI and functionality.
Native applications can use device functionality like camera,contacts et cetera.


2)Hybrid Mobile Applications:
Such applications use a skeleton native application and load web content in it
This web content may be static(where the served html,js,css etc are packaged with the application and reside on a users device) or dynamic (where the content is served from a server)
You can use the various HTML5 technologies and come up with an amazing user interface.
Hybrid applications can use device functionality like camera , contacts et cetera,thanks to the skeleton native application.

3)Mobile Web Application::
This is your traditional  web application loaded on a device browser (Eg : WebKit,Chrome,Firfox on Android)
This may be (or may not be) different from the application that loads in your desktop browser.
For example-m.facebook.com is the mobile web application of facebook.com
Application developers can customize their websites to load content more efficiently ,given the limited resources of a mobile device.
Mobile web applications cannot use device functionality


Check out this really cool video by Intel differentiating between how content is served in a mobile web application and in a hybrid mobile application.

Debugging application startup with plugins in Websphere Application Server

This post mainly addresses the errors observed during installing a application in Websphere Application Server . Most of the stuff I shall write about are generic to WAS 7 ,WAS 8 and WAS 8.5

1) So what happens when you install a new application through the WAS Admin console , and post successful installation it does not start ???

Observe the application startup logs in  your application server folder in profile
Eg : C:\IBM\WebSphere\AppServer\profiles\AppSrv01\logs\server1
or C:\IBM\WebSphere\AppServer\profiles\AppSrv01\logs\webserver1
Go through the logs and you should get idea of whats wrong.

2) If Step 1 fails , and the logs show only IBM related errors, then it might be a good idea to look for and install any applicable fixpaks. These fixpaks are cumulative so the latest should suffice

Eg: I was trying to install an application in WAS 8.5 and though the installation was successful , the applciation would not start .  The logs at C:\IBM\WebSphere\AppServer\profiles\AppSrv01\logs\ffdc
said  :
[11/11/13 9:40:36:513 IST]     FFDC Exception:com.ibm.ws.exception.RuntimeError SourceId:com.ibm.ws.runtime.component.CompositionUnitMgrImpl ProbeId:679 Reporter:com.ibm.ws.runtime.component.CompositionUnitMgrImpl@e341fce8
com.ibm.ws.exception.RuntimeError: java.lang.RuntimeException: java.lang.ArrayIndexOutOfBoundsException
at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:792)
..
..
..
Caused by: java.lang.ArrayIndexOutOfBoundsException
at org.objectweb.asm.ClassReader.readClass(Unknown Source)
at org.objectweb.asm.ClassReader.accept(Unknown Source)
at org.objectweb.asm.ClassReader.accept(Unknown Source)

Appeared to be an application issue,but after a lot of browsing realised that the fix was in one of the fixpaks
So stay on the latest fixpak if possible

Now what happens when you application has started successfully

1)Try to access your application through the application server port
Eg: http://localhost:9080/<context-root>/<web-page>

If this works well for you , that means the setup is correct
Otherwise,ensure that the URL you are accessing is correct, and simple html,jsp files etc are accessible

2) If you'r able to access your URL through the application server,but you are getting a 404 error on trying to access it through the web server ,follow the below mentioned steps :
-Make sure your http.conf has the following entries :
LoadModule was_ap22_module "C:\IBM\WebSphere\Plugins\bin\32bits\mod_was_ap22_http.dll"
WebSpherePluginConfig "C:\IBM\WebSphere\Plugins\config\webserver1\plugin-cfg.xml"

-Check your webserver logs  for errors
Eg : Ensure the follwoing text appears
[Mon Nov 11 12:57:52 2013] [notice] PLUGIN: mod_was_ap22_http: apache_log_header: WebSphere Plugins loaded.
[Mon Nov 11 12:57:52 2013] [notice] PLUGIN: mod_was_ap22_http: apache_log_header: --------------------Plugin Information-----------------------
[Mon Nov 11 12:57:52 2013] [notice] PLUGIN: mod_was_ap22_http: apache_log_header: Bld version: 8.5.0
[Mon Nov 11 12:57:52 2013] [notice] PLUGIN: mod_was_ap22_http: apache_log_header: Bld date: Apr 24 2012, 15:12:31
[Mon Nov 11 12:57:52 2013] [notice] PLUGIN: mod_was_ap22_http: apache_log_header: Webserver: IBM_HTTP_Server
[Mon Nov 11 12:57:52 2013] [notice] PLUGIN: mod_was_ap22_http: apache_log_header: --------------------------------------------------------------

My log had additional errors: 
File does not exist: C:/IBM/HTTPServer/htdocs/<application context-root>
Since plugins were configured ,this meant that the plugin-cfg.xml file was incomplete
Read on to know more ...

-plugin-cfg.xml
When any application has to be rerouted to the application server to the web server,plugins need to be generated specifically for that application . One plugin-cfg.xml file is updated(Operation "Generate plugins") and propagation involves pasting this file in the various app server,web server and dmgr locations (Operation "Propogate Plug In") . 

Sample locations :

C:\IBM\WebSphere\Plugins\config\webserver1\plugin-cfg.xml

C:\IBM\WebSphere\AppServer\profiles\Dmgr01\config\cells\CFWIN2012X64-4Cell01\nodes\CFWIN2012X64-4Node01\servers\webserver1\plugin-cfg.xml

C:\IBM\WebSphere\AppServer\profiles\AppSrv01\config\cells\CFWIN2012X64-4Cell01\nodes\CFWIN2012X64-4Node01\servers\webserver1\plugin-cfg.xml 

If any time a plugin-cfg.xml is created in the Dmgr01 file path ( as shown in sample location 2) , any changes made to the plugin-cfg.xml are not reflected to it.Hence it will always remain out of sync with the other plugin-cfg.xml files

 The trick is to make sure all the plugin-cfg.xml files are in sync,bear the same timestamp and content.just search plugin-cfg.xml files in your IBM roots,copy paste and restart web server.

This will also resolve the incomplete plugin-cfg.xml issue mentioned above


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