private async Task <decimal> GetGroupDesiredValue(AutoScalingGroup resource, AutoScalingResourceConfig config)
{
decimal?result = null;
if (config.InstanceCountIncreaseDelayMinutes != null)
{
result = await FetchLaggedGroupDesiredValueFromCloudWatch(resource, config.InstanceCountIncreaseDelayMinutes.Value);
}
return(result ?? resource.DesiredCapacity);
}
public async Task <decimal> GetValue(AutoScalingGroup resource, AutoScalingResourceConfig config, string property)
{
if (config == null)
{
throw new ArgumentNullException(nameof(config));
}
switch (property)
{
case "GroupDesiredCapacity":
return(await GetGroupDesiredValue(resource, config));
}
throw new Exception("Unsupported property name");
}
private async Task <decimal> GetGroupDesiredValue(AutoScalingGroup resource, AutoScalingResourceConfig config)
{
if (config.InstanceCountIncreaseDelayMinutes == null)
{
return(resource.DesiredCapacity);
}
var delaySeconds = config.InstanceCountIncreaseDelayMinutes.Value * 60;
var now = _timeProvider.UtcNow;
var metric = await _cloudWatch.GetMetricStatisticsAsync(
new GetMetricStatisticsRequest()
{
Dimensions = new List <Dimension>()
{
new Dimension()
{
Name = "AutoScalingGroupName",
Value = resource.AutoScalingGroupName
}
},
Statistics = new List <string>()
{
"Minimum"
},
Namespace = "AWS/AutoScaling",
Period = delaySeconds,
MetricName = "GroupDesiredCapacity",
StartTime = now.AddSeconds(-1 * delaySeconds),
EndTime = now
}
);
var threshold = metric.Datapoints.FirstOrDefault();
if (threshold == null)
{
throw new Exception(
$"No datapoints returned when requesting desired capacity from CloudWatch for {resource.AutoScalingGroupName}");
}
return((decimal)threshold.Minimum);
}
