There is nothing sacred about electrons being called negative charge and protons positive charge.Itâs just a convention. You, can very well call electrons as positive charge and protons as negative charge!
Single Node or Psuedo-Distributed Cluster is the one in which all the essential daemons (like NameNode, DataNode, JobTracker and TaskTracker) run on the same machine. The default replication factor for a single node cluster is 1. A single node cluster is basically used to simulate a full cluster like environment and to test hadoop applications and unlike the Stand-alone mode, HDFS is accessible in this.
A majority node set is a single quorum resource, from a server cluster perspective; however, the data is actually stored on multiple disks across the cluster. cluster running with a majority node set quorum resource, on the other hand, will only start up or continue running if a majority of the nodes configured for the cluster are up and running and can all communicate with each other. The failure semantics of the cluster are different from a vanilla MSCS cluster.