public class Checkpoint extends Pipe
Tapis added to the
FlowDef.addCheckpoint(Checkpoint, cascading.tap.Tap)method, that Tap instance will be used to capture the intermediate result sets. It is required that any Scheme used as a checkpoint must source
Fields.ALL. If used with a
Schemeclass and the
true, a header with the resolved field names will be written to the file. This is especially useful for debugging complex flows. For the
HadoopFlowConnectorand Hadoop platform, a Checkpoint will force a new MapReduce job (
Flowplan. This can be important when used in conjunction with a
HashJoinwhere all the operations upstream from the HashJoin significantly filter out data allowing it to fit in memory.
|Constructor and Description|
Constructor Checkpoint creates a new Checkpoint pipe which inherits the name of its previous pipe.
Constructor Checkpoint creates a new Checkpoint pipe with the given name.
equals, getConfigDef, getHeads, getName, getNodeConfigDef, getParent, getPrevious, getStepConfigDef, getTrace, hasConfigDef, hashCode, hasNodeConfigDef, hasStepConfigDef, id, isEquivalentTo, named, names, outgoingScopeFor, pipes, print, printInternal, resolveIncomingOperationArgumentFields, resolveIncomingOperationPassThroughFields, setParent, toString
public Checkpoint(Pipe previous)
previous- of type Pipe
Copyright © 2007-2015 Concurrent, Inc. All Rights Reserved.