How does Facebook work--The technology

Social networking is the art of connecting with those who share common interests. Your ‘network’ is a community that helps keep you united with others and offers many benefits. Networking via social media sites has revolutionized how we use the Internet and is at the forefront of what we now call Web 2.0.

Facebook is social networking. People have been “facebooking” each other for about 6 years now, makingFacebook the most used social network with over 350 million users worldwide. But how does Facebook work?

In this article, I will discuss Facebook’s inner workings, covering its architecture and frontend/backend infrastructure—the nuts and bolts that hold Facebook together.

How Does Facebook Work?—The Front End

Facebook uses a variety of services, tools, and programming languages to make up its core infrastructure. At the front end, their servers run a LAMP (Linux, Apache, MySQL, and PHP) stack with Memcache. Not a computer science expert? Let’s take a look at exactly what that means.

Linux & Apache

This part is pretty self-explanatory. Linux is a Unix-like computer operating system kernel. It’s open source, very customizable, and good for security. Facebook runs the Linux operating system on Apache HTTP Servers. Apache is also free and is the most popular open source web server in use.

MySQL

For the database, Facebook utilizes MySQL because of its speed and reliability. MySQL is used primarily as a key-value store as data is randomly distributed amongst a large set of logical instances. These logical instances are spread out across physical nodes and load balancing is done at the physical node level.

As far as customizations are concerned, Facebook has developed a custom partitioning scheme in which a global ID is assigned to all data. They also have a custom archiving scheme that is based on how frequent and recent data is on a per-user basis. Most data is distributed randomly.

PHP

Facebook uses PHP because it is a good web programming language with extensive support and an active developer community and it is good for rapid iteration. PHP is a dynamically typed/interpreted scripting language.

Memcache

Memcache is a memory caching system that is used to speed up dynamic database-driven websites (like Facebook) by caching data and objects in RAM to reduce reading time. Memcache is Facebook’s primary form of caching and helps alleviate the database load.

Having a caching system allows Facebook to be as fast as it is at recalling your data. If it doesn’t have to go to the database it will just fetch your data from the cache based on your user ID.

Downsides to Using LAMP

Facebook has realized that there are downsides to using the LAMP stack. Notably, PHP is not necessarily optimized for large websites and therefore hard to scale. Also, it is not the fastest executing language and the extension framework is difficult to use.

Mike Schroepfer, Facebook’s Vice President of Engineering, recently did an interview atEmTech@MIT concerning this. “Scaling any website is a challenge,” Schroepfer said, “but scaling a social network has unique challenges.”

He went on to say that unlike other websites, you can’t just add more servers to solve the problem because of Facebook’s “huge interconnected dataset.” New connections are created all the time due to user activity.

Facebook has grown so quickly that they are often faced with issues regarding database queries, caching, and storage of data. Their database is huge and largely complex. To account for this, Facebook has started a lot of open source projects and backend services.

How Does Facebook Work?—The Back End

Facebook’s backend services are written in a variety of different programming languages including C++, Java, Python, and Erlang. Their philosophy for the creation of services is as follows:

1. Create a service if needed

2. Create a framework/toolset for easier creation of services

3. Use the right programming language for the task

A list of all of Facebook’s open source developments are available. I will discuss a few of the essential tools that Facebook has developed.

Thrift (protocol)

Thrift is a lightweight remote procedure call framework for scalable cross-language services

development. Thrift supports C++, PHP, Python, Perl, Java, Ruby, Erlang, and others. It’s quick, saves development time, and provides a division of labor of work on high-performance servers and applications.

Scribe (log server)

Scribe is a server for aggregating log data streamed in real-time from many other servers. It is a scalable framework useful for logging a wide array of data. It is built on top of Thrift.

Cassandra (database)

Cassandra is a database management system designed to handle large amounts of data spread out across many servers. It powers Facebook’s Inbox Search feature and provides a structured key-value store with eventual consistency.

HipHop for PHP

HipHop for PHP is a source code transformer for PHP script code and was created to save server resources. HipHop transforms PHP source code into optimized C++. After doing this, it uses g++ to compile it to machine code.

  

Conclusion

In a nutshell, that’s Facebook. This article could easily be 37 pages longer if I were to go into more detail, but to answer the question “How does Facebook work?” I think this will suffice. If you look past all of the features and innovations the main idea behind Facebook is really very basic—keeping people connected. Facebook realizes the power of social networking and is constantly innovating to keep their service the best in the business.

Satisfaction...

There was once a businessman who was sitting by the beach in a small Brazilian village.
As he sat, he saw a Brazilian fisherman rowing a small boat towards the shore having caught quite few big fish.
The businessman was impressed and asked the fisherman, “How long does it take you to catch so many fish?”
The fisherman replied, “Oh, just a short while.”
“Then why don’t you stay longer at sea and catch even more?” The businessman was astonished.
“This is enough to feed my whole family,” the fisherman said.
The businessman then asked, “So, what do you do for the rest of the day?”
The fisherman replied, “Well, I usually wake up early in the morning, go out to sea and catch a few fish, then go back and play with my kids. In the afternoon, I take a nap with my wife, and evening comes, I join my buddies in the village for a drink — we play guitar, sing and dance throughout the night.”

The businessman offered a suggestion to the fisherman.
“I am a PhD in business management. I could help you to become a more successful person. From now on, you should spend more time at sea and try to catch as many fish as possible. When you have saved enough money, you could buy a bigger boat and catch even more fish. Soon you will be able to afford to buy more boats, set up your own company, your own production plant for canned food and distribution network. By then, you will have moved out of this village and to Sao Paulo, where you can set up HQ to manage your other branches.”

The fisherman continues, “And after that?”
The businessman laughs heartily, “After that, you can live like a king in your own house, and when the time is right, you can go public and float your shares in the Stock Exchange, and you will be rich.”
The fisherman asks, “And after that?”
The businessman says, “After that, you can finally retire, you can move to a house by the fishing village, wake up early in the morning, catch a few fish, then return home to play with kids, have a nice afternoon nap with your wife, and when evening comes, you can join your buddies for a drink, play the guitar, sing and dance throughout the night!”
The fisherman was puzzled, “Isn’t that what I am doing now?”

Mumbaiya Lifestyle

Samundar mein tairta hua ek jahaj

us jahaj par tainaat kai jaabaaz

Doctors,engineers,pilot aur kai kaamkaaj !

Na le paate ugta suraj dekhne ka mazaa

jo doobe rehte padhne mein bussiness aur stock market ki news taaza !

Itne busy hai, ke pata nahi chal raha night hai ya noon

lekin pata zaroor hai kaun ban gaya current bussiness tycoon !

Aur kahaan unhe fursat dekhne ko sunset

lage jo rehte hardum karne mein life set !

Aur phir ek din ho jaata hai life ka "The End"

Kya kare yaaron yahi to hai unka funda---

"Struggling till the End"

Happiness Mantra

I saw a five-year old getting a window seat in Mumbai's crowded railway.I still recollect the smile and happiness on his face as if he had conquered the whole world. The five-year old mind just had the opportunity of being happy on getting a window seat. But what about us? Even if we get a window seat, we have lots of other things running continuously into our mind.Our minds are burdened 24/7 with some or the other tensions.Sometimes I really feel jealous of that five year old mind. I wonder why dont this 21 year old mind feel such sort of happiness ?

If asked "are you happy?" most of them would say "yes and no". That set me thinking.May be its because their unhappiness is much more stronger than their happpiness.

We often crave for something and when this finally does happen,we often find there is something else that is upsetting us.The happiness of achieving what we desperately wanted does not reduce the sadness of what is upsetting us right now.This has got to do something with our mindset.If we could train our mind so that we can stay focussed on the happy events and ignore the unhappy ones, then we have found a good solution to more happy moments and less sad ones.This doesnt mean that we can escape from a sad situation.In fact we can disconnect from it and try to do something about it without getting emotional or upset.The result of such an effort will always bear better fruits.

One who has learnt to focus on what one has, rather than on what one does not, has learnt the mantra to happiness.