private ScaleStatus GetScaleStatusCore(int workerCount, DurableTaskTriggerMetrics[] metrics)
{
var scaleStatus = new ScaleStatus()
{
Vote = ScaleVote.None
};
if (metrics == null)
{
return(scaleStatus);
}
var heartbeats = new PerformanceHeartbeat[metrics.Length];
for (int i = 0; i < metrics.Length; ++i)
{
TimeSpan workItemQueueLatency;
bool parseResult = TimeSpan.TryParse(metrics[i].WorkItemQueueLatency, out workItemQueueLatency);
heartbeats[i] = new PerformanceHeartbeat()
{
PartitionCount = metrics[i].PartitionCount,
WorkItemQueueLatency = parseResult ? workItemQueueLatency : TimeSpan.FromMilliseconds(0),
WorkItemQueueLength = metrics[i].WorkItemQueueLength,
};
if (metrics[i].ControlQueueLengths == null)
{
heartbeats[i].ControlQueueLengths = new List <int>();
}
else
{
heartbeats[i].ControlQueueLengths = JsonConvert.DeserializeObject <IReadOnlyList <int> >(metrics[i].ControlQueueLengths);
}
if (metrics[i].ControlQueueLatencies == null)
{
heartbeats[i].ControlQueueLatencies = new List <TimeSpan>();
}
else
{
heartbeats[i].ControlQueueLatencies = JsonConvert.DeserializeObject <IReadOnlyList <TimeSpan> >(metrics[i].ControlQueueLatencies);
}
}
DisconnectedPerformanceMonitor performanceMonitor = this.GetPerformanceMonitor();
var scaleRecommendation = performanceMonitor.MakeScaleRecommendation(workerCount, heartbeats.ToArray());
bool writeToUserLogs = false;
switch (scaleRecommendation?.Action)
{
case ScaleAction.AddWorker:
scaleStatus.Vote = ScaleVote.ScaleOut;
writeToUserLogs = true;
break;
case ScaleAction.RemoveWorker:
scaleStatus.Vote = ScaleVote.ScaleIn;
writeToUserLogs = true;
break;
default:
scaleStatus.Vote = ScaleVote.None;
break;
}
this.traceHelper.ExtensionInformationalEvent(
this.hubName,
string.Empty,
this.functionName.Name,
$"Durable Functions Trigger Scale Decision: {scaleStatus.Vote.ToString()}, Reason: {scaleRecommendation?.Reason}",
writeToUserLogs: writeToUserLogs);
return(scaleStatus);
}
