Skip to main content

Map Reduce Simplified

Yes it is about parallel and distributed computing, there are tonnes of web pages, books articles, diagrams etc. etc with nice buzz words to talk about Map Reduce, here is the most simplified explanation.

Lets take a real life example.

1. Company CEO called all Program Manager's "I need total effort spent this month by noon". Program Manager's no problem sir. Why are Program Manager's not worried because they are going to distribute task :-)

2. Each Program Manager called their project manager asking for effort spent so far.

3. Each Project Manager pulled up effort sheet and provided it to their Program Managers.

4. Program Managers complied received sheet into one file and sent it to CEO.

5. Company CEO collated all the sheets and calculated total effort spent.

Each individually broke its task to smaller tasks (Mapped its input task to smaller tasks), Program Manager was required to provide effort spent, he mapped his task to smaller tasks, this is MAP.

Program Manager's on receiving data from their project managers compiled it back to single output, this is REDUCE.

Now lets zoom out and summarize how Map Reduce applies to distributed and parallel computing. Each node distributes its task to smaller tasks(Maps its given task). Each node receive results, combine them(REDUCE) to generate required output.


Labels:

Comments

Post a Comment

Popular posts from this blog

Listen Hindi Internet Radio Channels on PS3

PS3 is the best gadget i have ever used and its true "It only do everything". Having used it to play games, watch netflix, youtube and see my collection of pictures and listen to songs. I was searching for a way to play radio on PS3 and specifically "Hindi Internet Radio Channels" After spending couple of days, finally I have it working in few easy steps: 1. Download PS3 Media server on you laptop or PC: http://ps3mediaserver.blogspot.com/ 2. Open WEB.conf file of PS3 and add following lines: audiostream.Web,Radio=Desi Radio - www.desi-radio.com,http://76.73.90.27:80/ audiostream.Web,Radio=Desi-Radio - www.desi-radio.com,http://76.73.126.218:80/ 3. Restart PS3 Media Server 4. In your PS3, you should see PS3 Media server, open following path: Web -> Radio You should see "Desi Radio" in list. 5. Click on Desi Radio and you have live hindi songs streaming on your Ps3. I am searching more hindi internet radio channels, will update this blog when i find more...
7 comments
Read more

MQTT : Android step by step guide using Eclipse Paho

For MQTT integration, recently explored Paho Android project, very simple to use, here are the steps: Intialize a client, set required options and connect.     MqttAndroidClient mqttClient = new MqttAndroidClient(BaseApplication.getAppContext(), broker, MQTT_CLIENT_ID);     //Set call back class     mqttClient.setCallback(new MqttCallbackHandler(BaseApplication.getAppContext()));     MqttConnectOptions connOpts = new MqttConnectOptions();     IMqttToken token = mqttClient.connect(connOpts); Subscribe to a topic.     token.setActionCallback(new IMqttActionListener() {       @Override       public void onSuccess(IMqttToken arg0) {            mqttClient.subscribe("TOPIC_NAME" + userId, 2, null, new IMqttActionListener() {                 @Override                 public void ...
Post a Comment
Read more

Learn to Play Keyboard

One day I started searching internet about the same thing, how to play keyboard, went through a number of sites, blogs etc.. etc. But finally i learned it on my own, yes dont get surprised this is truth, because most of the sites will just provide you information on keyboard notes etc. But none of them tell you what goes wrong that you dont end up with success in keyboard playing. Well I am sharing my experience here, along with a couple of steps which I hope will be really helpful to you. Please read it like a story not like a lesson about keyboard learning, this will make it easy for you to learn keyboard. Also, this is for those who are busy with their life but still want to lean to play keyboard. First and foremost thing: a) Keep your keyboard at a place, where you can see it, see it in the morning when you get up, see it easily when you go around in your home, dont dump it into an almirah or trunk, this helps, dont get surprised, because everytime you see it at the back of the min...
5 comments
Read more