cluster-computing

I am trying to find out where does the output of a Map task is saved to disk before it can be used by a Reduce task. Note: - version used is Hadoop 0.20.204 with the new API For example, when overwriting the map method in the Map class: public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException { String line = value.toString(); StringTokenizer tokenizer = new StringTokenizer(line); while (tokenizer.hasMoreTokens()) { word.set(tokenizer.nextToken()); context.write(word, one); } // code that starts a new Job. } I am interested to find out where does

How can I run 3 cassandra nodes (actually a cluster) from my Ubuntu? I don't want to create 3 instances of VMWare/VirtualBox but instead, configure each cassandra node to listen to a different port. Is that possible with one cassandra installation? A solution that came to my mind is to have 3 local cassandra installation and configure each cassandra.yaml independently but actually I would prefer to have achieve that by my installed cassandra configuration files. I need such configuration only for testing purposes, obviously. hjarraya Check this Cassandra Cluster Manager on github https:/

What is the difference between a Cluster and MPP supercomputer architecture? Peter Rowell In a cluster, each machine is largely independent of the others in terms of memory, disk, etc. They are interconnected using some variation on normal networking. The cluster exists mostly in the mind of the programmer and how s/he chooses to distribute the work. In a Massively Parallel Processor, there really is only one machine with thousands of CPUs tightly interconnected. MPPs have exotic memory architectures to allow extremely high speed exchange of intermediate results with neighboring processors.

I'm trying to implement a cluster using Erlang as the glue that holds it all together. I like the idea that it creates a fully connected graph of nodes, but upon reading different articles online, it seems as though this doesn't scale well (having a max of 50 - 100 nodes). Did the developers of OTP impose this limitation on purpose? I do know that you can setup nodes to have explicit connections only as well as have hidden nodes, etc. But, it seems as though the default out-of-the-box setup isn't very scalable. So to the questions: If you had 5 nodes (A, B, C, D, E) that all had explicit

I am working on a project that requires really high availability and my team is currently working on upgrading some infra-structure and software for a future release. One of the features we would like to enable is to have session replication across not only different servers, but ideally across different sites (geographically spread). Is that possible? What are the approaches? For what I have seen so far, to enable session replication, the usual vendor approaches are either one of these: Serializable session attributes < distributable /> tag in the web.xml with additional configuration in

Question: Is it possible to cluster an application which is using Socket.io for WebSocket support? If so what would be the best method of implementation? I've built an application which uses Express and Socket.io, built on Node.js. I'd like to incorporate clustering to increase the amount of requests that my application can process. The following causes my application to produce a socket handshake error... var cluster = require('cluster'); var numCPUs = require('os').cpus().length; if (cluster.isMaster) { // Fork workers. for (var i = 0; i < numCPUs; i++) { cluster.fork(); } cluster.on('death'

Context and current state We are migrating our cluster from Cassandra to a full ElasticSearch cluster. We are indexing documents at average of ~250-300 docs per seconds . In ElasticSearch 1.2.0 it represents ~8Go per day. { "generic": { "id": "twi471943355505459200", "type": "twitter", "title": "RT @YukBerhijabb: The Life is Choice - https://m.facebook.com/story.php?story_fbid=637864496306297&id=100002482564531&refid=17", "content": "RT @YukBerhijabb: The Life is Choice - https://m.facebook.com/story.php?story_fbid=637864496306297&id=100002482564531&refid=17", "source": "<a href=\"https:/