Basic node.js implementation of distributed Map/Reduce

The implementation includes the example of Map/Reduce operation in a Master/Slave setup.
Each slave node has the data represented as HashMap<key, value>. Master/reduce node sends the Map function, gathers the data from all connected nodes, does the groupby Key op. and reduces the values for the same key. The output is a HashMap<key, reduced_value>.

Each node has a name and the data passed through shell arguments when running the process. For the sake of simplicity data is represented as values in range(from, to) (see in Docs sec.). The Map/Reduce op. starts on GET request to /start-map endpoint of Master server

Docs

node client.js FROM TO NODE_NAME - serves the data storage slave node

• FROM/TO -- setups the data of a node - range of values from FROM to TO inclusive;
• NODE_NAME -- the name of the node in interprocess communication;

node server.js - serves master/reduce node

E.x. Run:

1. npm install # to install the dependencies
2. node server.js # to start a Reducer server
3. node client.js 10 50 Cat # Node1
4. node client.js 40 80 Dog # Node2
5. Make a GET request to http://localhost:8080/start-map/