How Facebook store data and images

what is cloud computing?
   Cloud Computing is a technology used to store huge amounts of data in imaginary data server called cloud. Its main purpose to serve any where , any time data. one access to see data.

Pros
    Primary pro is Infrastructure-less. Let us consider story of Pinterest company . It start up company used Amazon EC2(Elastic cloud) and hosted their application . Amazon EC2 is brilliant architecture which can be expanded the CPU usage of  servers on traffic increase. Now you can see that Pin Interest did not worry about server setup , software resources and employees for handling those. it just concentrated on their main business to server the users rather than focusing of infrastructure.

Pinterest
     Pinterest pays about $52 an hour to Amazon during peak hours of the day, and about $15 during the night when traffic on the app is less (most of its customers are in the US).


Cloud Computing use by Facebook

What is Apache Cassandra -No sql

What is Apache Cassandra?

   Its a no sql database which is mainly used to storing Big data. It famous for its Fault tolerance ,scalability, availability and Performance. Its used by Facebook ,ebay , Go-daddy and other popular companies.

   One of the largest production deployments consists of over 15,000 nodes storing over 4 PB of data. Other large Cassandra installations include Netflix (2,500 nodes, 420 TB, over 1 trillion requests per day), Chinese search engine Easou (270 nodes, 300 TB, over 800 million reqests per day), and eBay (over 100 nodes, 250 TB).   

For more Info -- http://cassandra.apache.org/

Source Control management System free- Configuration Management system free

What is CMS?

   CMS is meant for configuration management system which mainly used to control the Source Code.

Why we need CMS?
     
   Consider an organisation like Microsoft has 1000's of projects going on or Let us consider designing an Airway Reservation system which involves lot of modules and lot of coding. 100's of employees will be working on the code globally . There s need of system which can control the code changes by employees for that module.
  CMS make sure that no two person work on same code. It has a concept called check in and check out.
It uses one central repository (storage) and initial project will be pushed to that . Every one takes the update from the central repository and starts working on it. If Person A and Person B are working on  file named FILE 1 then CMS plays vital role.
 
     Scenario :

         With out CMS

                       Person A acquired  the FILE 1 and started modifying . Consider Person B also want to change something in the same file same be same method what A is changing. When both are changing . they dont know each other about the changes. Finally a weird file will be created. If its in same office, no problem . Imagine A is in India and B is USA.

   With CMS
                 
                  According to CMS,   Person A can check out the File from central repo. If B wants to modify something , he has to take update or he modify something and about to check in to repo . He will be thrown an exception stating that Person A is already checked out the file and modified something . As Person B  is notified , he will wait till A change updates then B can check the changes and incorporate if any needed.

   This is what called Source Control Management system / Version Control Management System /Configuration Management System

Tools

Open Source

   > Git Hub is the best source control management system.

Closed Source

 > SVN  Tortoise
 > VSS (Visual source safe)
 > a lot more..... (just google it)


  GitHub is world famous source control system. it's used by top class IT companies like Facebook and Open source geeks

Side Effects of Protein -Whey-Isolate vs Concentrate

What is Whey?

 Whey is a form of Protein extracted in the process of making cheese from milk. The Liquid form is dried to make Whey protein . Its the Concentrate form.

What is Whey Isolate?

    Whey Isolate is the extracted form from Whey Concentrate. A machinery is used to remove the other components like Fat ,Carbohydrates and leave only protein. Its the Purest form and contains around 85-95% of protein. Its good for building lean muscle.

What is Whey Concentrate?

   Whey Concentrate is the first step of protein arrived from the extraction process. It contains Fat, Lactose,Carbo and higher amounts of protein. Protein percentage is about 75-80%. Its good for health as you are getting other components to your body.


Isolate Vs  Concentrate
 
   Isolate is further extracted part of concentrate. so that's the reason its price is double compared to concentrate. I personally feel Concentrate is better as it contains other form of components needed for our body . If you are solely interested in body building and interested in purest protein taking , you can go a head with Isolate .
                 Take More water to control protein in take

Side Effects of Protein

 >   Excessive intake of anything bad for health.
 >   Take Limited protein and control it by taking more water.
>   One should take >= gm/ 1 lb (weight in pounds)
    Ex: A person with 60 kgs = > 60 * 2.2 =>132 lb
        So one should take  130 gm/ day

 Control it by taking more Water.