map

Problem I need a key-value store that can store values of the following form: DS<DS<E>> where the data structure DS can be either a List…

we use a hadoop multi-node setup on debian + ubuntu with the latest stable hadoop release. is it possible to set a specific slave to be the reducer?…

After much wrestling with the idea of ranking records, I finally settled on numeric based scores for my documents, which I emit to have them sorted…

i want Australia map showing its state and there is a stock list against each state when you click on the the state then it shows its stock list of…

hi all, i want to implement hive+hadoop map reduce program on my aplication, i still wondering,because i have try many times about query and finding…

For some reason I'm only getting a null key from map/reduce result in couchdb on mac Result: {"rows":[ {"key":null,"value":2224} ]} Im using…

Lets say you have 2 doc types.... customers and orders. Customer doc contains basic info... name, address etc. and then orders contain all the order…

Scenario A client application that features a map. The map is an interactive control that upon move/zoom will request tiles (as needed) from a tile…

Hi friends. I have to implement the following map-->Reduce1-->Reduce 2 means the Reduce2 is a separate operation on output of Reduce 1. I want…

I'd like to use an entire file as a single record for MAP processing, with the filename as the key. I've read the following post: How to get…

HI everyone I am new to hadoop map reduce, i wanted to know that there is some outputformat type which can allow me to emit a matrix(2d array)…

I have a question regarding Joins in Map/Reduce. If I want to do inner join in hadoop Map/Reduce how would I do it. I have heard of…

Hello everyone, I have another question for you: The code below does the following 1) For each file in a folder 2) Open the file and read its…

Hi, In a 3 node hadoop cluster. I would like the master to be 1 node. Map task taking place in one node and reduce tasks in 1 node. Map and reduce…

I'm trying to do a simple map reduce in the Mongo shell, but the reduce function never gets called. This is my code : db.sellers.mapReduce(…

Hi, I've got 3 types of documents in my db: { param: "a", timestamp: "t" } (Type 1) { param: "b", partof: "a" } (Type 2) { param: "b", timestamp:…

Hi, When I was trying the Map Reduce programming example from Hadoop in Action book based on Hadoop 0.20 API I got the error java.io.IOException:…

Hello All, I have a collection of events=[ timestamp, accountId, deviceId, rfid ...] -rfids is nullable, but everything else is not nullable -the…

The codes below send a request to server and the server sends a response back. Then, the client formats the request and makes it a url that it loads…

The codes below send a request to server and the server sends a response back. Then, the client formats the request and makes it a url that it loads…