G)Fault Tolerance Reactive way v orker failure Heartbeat, Workers are periodically pinged by master NO response= failed worker If the processor of a worker fails, the tasks of that worker are reassigned to another worker. What about a completed map task or Reduce task? Master failure Master writes periodic checkpoints Another master can be started from the last checkpointed state If eventually the master dies, the job will be aborted 24Fault Tolerance 24 • Reactive way – Worker failure • Heartbeat, Workers are periodically pinged by master – NO response = failed worker • If the processor of a worker fails, the tasks of that worker are reassigned to another worker. • What about a completed Map task or Reduce task? – Master failure • Master writes periodic checkpoints • Another master can be started from the last checkpointed state • If eventually the master dies, the job will be aborted