internal virtual async Task <bool> UpdateQueueMetrics()
{
CloudQueue workItemQueue = AzureStorageOrchestrationService.GetWorkItemQueue(this.storageAccount, this.taskHub);
CloudQueue[] controlQueues = await AzureStorageOrchestrationService.GetControlQueuesAsync(
this.storageAccount,
this.taskHub,
defaultPartitionCount : AzureStorageOrchestrationServiceSettings.DefaultPartitionCount);
Task <QueueMetric> workItemMetricTask = GetQueueMetricsAsync(workItemQueue);
List <Task <QueueMetric> > controlQueueMetricTasks = controlQueues.Select(GetQueueMetricsAsync).ToList();
var tasks = new List <Task>(controlQueueMetricTasks.Count + 1);
tasks.Add(workItemMetricTask);
tasks.AddRange(controlQueueMetricTasks);
try
{
await Task.WhenAll(tasks);
}
catch (StorageException e) when(e.RequestInformation?.HttpStatusCode == 404)
{
// The queues are not yet provisioned.
AnalyticsEventSource.Log.MonitorWarning(
this.storageAccount.Credentials.AccountName,
this.taskHub,
$"Task hub has not been provisioned: {e.RequestInformation.ExtendedErrorInformation?.ErrorMessage}");
return(false);
}
QueueMetric workItemQueueMetric = workItemMetricTask.Result;
this.WorkItemQueueLatencies.Add((int)workItemQueueMetric.Latency.TotalMilliseconds);
int i;
for (i = 0; i < controlQueueMetricTasks.Count; i++)
{
QueueMetric controlQueueMetric = controlQueueMetricTasks[i].Result;
if (i >= this.ControlQueueLatencies.Count)
{
this.ControlQueueLatencies.Add(new QueueMetricHistory(QueueLengthSampleSize));
}
this.ControlQueueLatencies[i].Add((int)controlQueueMetric.Latency.TotalMilliseconds);
}
// Handle the case where the number of control queues has been reduced since we last checked.
while (i < this.ControlQueueLatencies.Count && this.ControlQueueLatencies.Count > 0)
{
this.ControlQueueLatencies.RemoveAt(this.ControlQueueLatencies.Count - 1);
}
this.currentPartitionCount = controlQueues.Length;
this.currentWorkItemQueueLength = workItemQueueMetric.Length;
this.currentControlQueueLengths = controlQueueMetricTasks.Select(t => t.Result.Length).ToArray();
return(true);
}
/// <summary>
/// Gets the scale-related status of the work-item queue.
/// </summary>
/// <returns>The approximate number of messages in the work-item queue.</returns>
protected virtual async Task <WorkItemQueueData> GetWorkItemQueueStatusAsync()
{
CloudQueue workItemQueue = AzureStorageOrchestrationService.GetWorkItemQueue(this.storageAccount, this.taskHub);
DateTimeOffset now = DateTimeOffset.Now;
Task fetchTask = workItemQueue.FetchAttributesAsync();
Task <CloudQueueMessage> peekTask = workItemQueue.PeekMessageAsync();
await Task.WhenAll(fetchTask, peekTask);
int queueLength = workItemQueue.ApproximateMessageCount.GetValueOrDefault(0);
TimeSpan age = now.Subtract((peekTask.Result?.InsertionTime).GetValueOrDefault(now));
if (age < TimeSpan.Zero)
{
age = TimeSpan.Zero;
}
return(new WorkItemQueueData
{
QueueLength = queueLength,
FirstMessageAge = age,
});
}