During normal operation DataNodes send heartbeats to the NameNode. The default heartbeat interval is three seconds. If the NameNode does not receive a heartbeat from a DataNode in ten minutes the NameNode considers the DataNode to be out of service. The NameNode schedules creation of new replicas of those blocks on other DataNodes. [3] ee a eee ee eee eee Hadoop MapReduce is a framework that can be used for executing applications containing vast amounts of data (terabytes of data) in parallel on largely built clusters with numerous nodes in a reliable and fault-tolerant manner. Though it can be executed in a single machine, its true power lies in its ability to scale to several thousands of systems each with several processor cores. Hadoop is designed in such a way that it distributes data efficiently across various nodes in the cluster. It includes a distributed file system that takes care of distributing the huge amount of data sets efficiently across the nodes in the cluster. The report consists of status and diagnostic
![During normal operation DataNodes send heartbeats to the NameNode. The default heartbeat interval is three seconds. If the NameNode does not receive a heartbeat from a DataNode in ten minutes the NameNode considers the DataNode to be out of service. The NameNode schedules creation of new replicas of those blocks on other DataNodes. [3] ee a eee ee eee eee Hadoop MapReduce is a framework that can be used for executing applications containing vast amounts of data (terabytes of data) in parallel on largely built clusters with numerous nodes in a reliable and fault-tolerant manner. Though it can be executed in a single machine, its true power lies in its ability to scale to several thousands of systems each with several processor cores. Hadoop is designed in such a way that it distributes data efficiently across various nodes in the cluster. It includes a distributed file system that takes care of distributing the huge amount of data sets efficiently across the nodes in the cluster.](https://figures.academia-assets.com/32082815/figure_002.jpg)
