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.
1 Every node is attached to one or more cluster storage devices. 2  Each cluster storage device attaches one or more disks. 3  The disks store all of the cluster's configuration and resource data. 4  Each disk can be owned by only one node at any point in time, but ownership can be transferred between nodes. Every node is attached to one or more cluster storage devices. 2  Each cluster storage device attaches one or more disks. 3  The disks store all of the cluster's configuration and resource data. 4  Each disk can be owned by only one node at any point in time, but ownership can be transferred between nodes.