AWS ECS Autoscaling有时会因terraform创建警报而失败

Question

我已经为AWS ECS向外扩展定义了CloudWatch警报。

通常正常。但有时会失败，并显示以下错误。 500是向外扩展的阈值。公制时间是每5分钟一次。并且横向扩展数据点为2分之一（意味着一个值在10分钟内超过阈值）：

  

“错误”：“未找到度量值的步进调整   [437.08774491907025，516.9558339660845]和违反阈值500.0“

步进调整的定义如下：

 step_adjustment {
      metric_interval_lower_bound = 0
      scaling_adjustment          = 1
    }

警报配置：

datapoints_to_alarm         = "1"
  evaluation_periods        = "2"
  threshold                 = "500"

用于创建警报的Terraform代码

resource "aws_appautoscaling_policy" "task_count_up" {
  name               = "appScalingPolicy_${aws_ecs_service.sqs_to_kinesis.name}_ScaleUp"
  service_namespace  = "ecs"
  resource_id        = "service/${aws_ecs_cluster.shared-elb-access-logs-processor.name}/${aws_ecs_service.sqs_to_kinesis.name}"
  scalable_dimension = "ecs:service:DesiredCount"

  step_scaling_policy_configuration {
    adjustment_type         = "ChangeInCapacity"
    cooldown                = "${var.scale_up_cooldown_seconds}"
    metric_aggregation_type = "Maximum"

    step_adjustment {
      metric_interval_lower_bound = 0
      scaling_adjustment          = 1
    }

  }

  depends_on = [
    "aws_appautoscaling_target.main",
  ]
}

resource "aws_appautoscaling_policy" "task_count_down" {
  name               = "appScalingPolicy_${aws_ecs_service.sqs_to_kinesis.name}_ScaleDown"
  service_namespace  = "ecs"
  resource_id        = "service/${aws_ecs_cluster.shared-elb-access-logs-processor.name}/${aws_ecs_service.sqs_to_kinesis.name}"
  scalable_dimension = "ecs:service:DesiredCount"

  step_scaling_policy_configuration {
    adjustment_type         = "ChangeInCapacity"
    cooldown                = "${var.scale_down_cooldown_seconds}"
    metric_aggregation_type = "Minimum"

    step_adjustment {
      metric_interval_upper_bound = 0
      scaling_adjustment          = -1
    }

  }

  depends_on = [
    "aws_appautoscaling_target.main",
  ]
}