Module V: Hadoop Technical Review。? Spinnaker Labs, Inc.。Overview。? Spinnaker Labs, Inc.。You Say, ―tomato…‖。Bigtable Chubby。Hadoop equivalent: Hadoop HDFS。Some MapReduce Terminology。– a.k.a. Task-In-Progress (TIP)。? Task Attempt – A particular instance of an attempt to execute a task on a machine。? Spinnaker Labs, Inc.。Terminology Example。? Spinnaker Labs, Inc.。Task Attempts。– If the same input causes crashes over and over, that input will eventually be abandoned。? Multiple attempts at one task may occur in parallel with speculative execution turned on。? Spinnaker Labs, Inc.。MapReduce: High Level。Slave node。Slave node。Slave node。TaskTracker。TaskTracker。TaskTracker。Task instance。Task instance。Task instance。? Spinnaker Labs, Inc.。Node-to-Node Communication。– Prevents circular-wait deadlock –