AWS Data Pipeline
Developer Guide (API Version 2012-10-29)

Exists

Checks whether a data node object exists.

Note

We recommend that you use system-managed preconditions instead. For more information, see Preconditions.

Example

The following is an example of this object type. The InputData object references this object, Ready, plus another object that you'd define in the same pipeline definition file. CopyPeriod is a Schedule object.

{ "id" : "InputData", "type" : "S3DataNode", "schedule" : { "ref" : "CopyPeriod" }, "filePath" : "s3://example-bucket/InputData/#{@scheduledStartTime.format('YYYY-MM-dd-hh:mm')}.csv", "precondition" : { "ref" : "Ready" } }, { "id" : "Ready", "type" : "Exists" }

Syntax

Optional Fields Description Slot Type
attemptStatus Most recently reported status from the remote activity. String
attemptTimeout Timeout for remote work completion. If set then a remote activity that does not complete within the set time of starting may be retried. Period
failureAndRerunMode Describes consumer node behavior when dependencies fail or are rerun. Enumeration
lateAfterTimeout The elapsed time after pipeline start within which the object must start. It is triggered only when the schedule type is not set to ondemand. Period
maximumRetries Maximum number attempt retries on failure Integer
onFail An action to run when current object fails. Reference Object, e.g. "onFail":{"ref":"myActionId"}
onLateAction Actions that should be triggered if an object has not yet been scheduled or still not completed. Reference Object, e.g. "onLateAction":{"ref":"myActionId"}
onSuccess An action to run when current object succeeds. Reference Object, e.g. "onSuccess":{"ref":"myActionId"}
parent Parent of the current object from which slots will be inherited. Reference Object, e.g. "parent":{"ref":"myBaseObjectId"}
preconditionTimeout The period from start after which precondition is marked as failed if still not satisfied Period
reportProgressTimeout Timeout for remote work successive calls to reportProgress. If set, then remote activities that do not report progress for the specified period may be considered stalled and so retried. Period
retryDelay The timeout duration between two retry attempts. Period

Runtime Fields Description Slot Type
@activeInstances List of the currently scheduled active instance objects. Reference Object, e.g. "activeInstances":{"ref":"myRunnableObjectId"}
@actualEndTime Time when the execution of this object finished. DateTime
@actualStartTime Time when the execution of this object started. DateTime
cancellationReason The cancellationReason if this object was cancelled. String
@cascadeFailedOn Description of the dependency chain the object failed on. Reference Object, e.g. "cascadeFailedOn":{"ref":"myRunnableObjectId"}
emrStepLog EMR step logs available only on EMR activity attempts String
errorId The errorId if this object failed. String
errorMessage The errorMessage if this object failed. String
errorStackTrace The error stack trace if this object failed. String
hadoopJobLog Hadoop job logs available on attempts for EMR-based activities. String
hostname The host name of client that picked up the task attempt. String
node The node for which this precondition is being performed. Reference Object, e.g. "node":{"ref":"myRunnableObjectId"}
reportProgressTime Most recent time that remote activity reported progress. DateTime
@scheduledEndTime Schedule end time for object. DateTime
@scheduledStartTime Schedule start time for object. DateTime
@status The status of this object. String
@version Pipeline version the object was created with. String
@waitingOn Description of list of dependencies this object is waiting on. Reference Object, e.g. "waitingOn":{"ref":"myRunnableObjectId"}

System Fields Description Slot Type
@error Error describing the ill-formed object. String
@pipelineId Id of the pipeline to which this object belongs to. String
@sphere The sphere of an object denotes its place in the lifecycle: Component Objects give rise to Instance Objects which execute Attempt Objects. String

See Also

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