The Request Tracking Process
The Change Deployment Configuration operation in the Windows Azure Service Management API enables you to change the number of role instances. This asynchronous operation returns a request ID to enable the caller to check later on the status of the operation by using the Get Operation Status operation. The request tracking process in the block uses these operations to perform scaling operations and to track them.
The Scaler class optionally uses the ServiceManagementRequestTracker class to track the success or failure of the scaling requests. After the Scaler class submits a configuration change request to Windows Azure using the ServiceManagementClient class, it logs the change request and invokes the RecordForTracking method of the ServiceManagementRequestTracker class. This method stores details of the change request in a Windows Azure queue.
|The ServiceManagementRequestTracker class creates the queue in the Windows Azure storage account identified by the serviceManagementRequestTracker element in the block's configuration data.|
One of the activities that the Metronome instance schedules invokes the CheckOperationStatus method in the ServiceManagementRequestTracker class. This method checks the status of change requests on the queue; if the status of the change request is "Failed" or "Succeeded," the method logs the result and removes the entry from the queue.
Last built: June 7, 2012