How is this distributed? Partition input key/value pairs into chunks, run mapo tasks in parallel After all mapos are complete, consolidate all emitted values for each unique emitted key Now partition space of output map keys, and run reducel in parallel If mapo or reduce fails, reexecuteExecution 15 • How is this distributed? ➢ Partition input key/value pairs into chunks, run map() tasks in parallel ➢ After all map()s are complete, consolidate all emitted values for each unique emitted key ➢ Now partition space of output map keys, and run reduce() in parallel • If map() or reduce() fails, reexecute!