Scalability & Perfoamce

Load balance your website.
1) Use DNS (Domain Name Server) to distribute your website load.
2) Use Load Balancing Switch to distribute your website load.
The above mentioned load balancing methods work very well for static websites. But if your website have to do back end processing with a database or any other service, then even those services have to be load balanced otherwise they would become the bottle neck.

The above stuff is just the beginning of the vast topic called "Scalability"!
Abstraction interface
1) System abstraction interface help in hiding the complexity of the actual system and also the changes with in the system transparent to users of the system like hardware upgrade or adding hardware resource to scale up....
Scalability on the client

1) Paging concept (showing only few mail subjects on a mail client)

Scalability on the web/app server

1) multiple threads to handle http request
2) Load balancing architecture (one load balancing proxy server with multiple app server) to handle http request


External resources

Let's make the web faster
Web browser capabilities
Online web page testing
High Performance Web Sites and YSlow
Even Faster Websites
steve souders

to be continued.....

Android Findings

onConfigurationChanged - orientation change
Having "android:configChanges="orientation|keyboard" in manifest reloads the android activity on orientation change.
Instead the correct property is

"android:configChanges="orientation|keyboardHidden".

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addJavascriptInterface - webview & javascript
When passing argument from javascript to android, pass it as string. Now if you want to convert the passed string to Integer or Long, the do not use Integer.getInteger instead use Integer.valueOf, that is, use valueOf.

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Java Math.ceil with Integers
If your try to do some thing like

Integer a=1;
Integer b=5;
Integer c=0;
c=(int)Math.ceil(a/b);
You will get only 0;

Instead do something like

Integer a=1;
Integer b=5;
Integer c=0;
c=(int)Math.ceil((a * 1.0)/b);
So that you will get 1.

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cursor.close() - Right place to close the sqlite cursor
Don't

if(cursor.getCount() > 0)
{
 cursor.close();
}

Do

if(cursor.getCount() > 0)
{

}
cursor.close();

Reference:https://groups.google.com/group/android-developers/browse_thread/thread/706258dfb7cbee1d

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