Amazon Simple Workflow Service Markers - Amazon Simple Workflow Service
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Amazon Simple Workflow Service Markers

You can use markers to record events in the workflow execution history for application specific purposes. Markers are useful when you want to record custom information to help implement decider logic. For example, you could use a marker to count the number of loops in a recursive workflow.

In the following example, the decider completes a decision task and responds with a RespondDecisionTaskCompleted action that contains a RecordMarker decision. RespondDecisionTaskCompleted { "taskToken":"12342e17-80f6-FAKE-TASK-TOKEN32f0223", "decisions":[{ "decisionType":"RecordMarker", "recordMarkerDecisionAttributes":{ "markerName":"customer elected special shipping offer" } }, ] }

If Amazon SWF successfully records the marker, it returns a successful HTTP response similar to the following.

HTTP/1.1 200 OK Content-Length: 0 Content-Type: application/json x-amzn-RequestId: 6c0373ce-074c-11e1-9083-8318c48dee96

Recording a marker doesn't, by itself, initiate a decision task. To prevent the workflow execution from becoming stuck, something must occur that continues the execution of the workflow. For example, this might include the decider scheduling another activity task, the workflow execution receiving a signal, or a previously scheduled activity task completing.