autoscaling

autoscaling.py

@@ -264,76 +264,46 @@ def create_auto_scaling_group(autoscaling_client, launch_template_id, target_gro
     print(f"Auto Scaling Group created with ARN: {asg_arn}")
     return asg_arn
 
-def put_scaling_policies(autoscaling_client, asg_arn):
-    # Put Scaling Policy Up
-    up = autoscaling_client.put_scaling_policy(
+def put_scaling_policy(autoscaling_client, asg_arn):
+    # Put Scaling Policy based on CPU Utilization
+    policy = autoscaling_client.put_scaling_policy(
         AutoScalingGroupName=f"{PREFIX}-asg",
-        PolicyName=f"{PREFIX}-scale-policy-up",
-        PolicyType='SimpleScaling',
-        AdjustmentType='ChangeInCapacity',
-        ScalingAdjustment=2,  # Scale up faster by adding 2 instances at a time
-        Cooldown=30  # Short cooldown for rapid scaling up
+        PolicyName=f"{PREFIX}-scale-policy-cpu",
+        PolicyType='TargetTrackingScaling',
+        TargetTrackingConfiguration={
+            'PredefinedMetricSpecification': {
+                'PredefinedMetricType': 'ASGAverageCPUUtilization'
+            },
+            'TargetValue': 20.0,  # Target CPU utilization percentage
+            'DisableScaleIn': False  # Allow scale in
+        }
     )
 
-    print(f"Scale-up policy created with ARN: {up['PolicyARN']}")
+    print(f"Scaling policy created with ARN: {policy['PolicyARN']}")
+    return policy['PolicyARN']
 
-    # Put Scaling Policy Down
-    down = autoscaling_client.put_scaling_policy(
-        AutoScalingGroupName=f"{PREFIX}-asg",
-        PolicyName=f"{PREFIX}-scale-policy-down",
-        PolicyType='SimpleScaling',
-        AdjustmentType='ChangeInCapacity',
-        ScalingAdjustment=-1,  # Scale down slower by removing 1 instance at a time
-        Cooldown=120  # Longer cooldown for scaling down
-    )
-
-    print(f"Scale-down policy created with ARN: {down['PolicyARN']}")
-    return up['PolicyARN'], down['PolicyARN']
-
-def create_cloudwatch_alarms(cloudwatch_client, sp_up, sp_down):
-    # Create CloudWatch Alarms for scaling up
+def create_cloudwatch_alarm(cloudwatch_client, sp_arn):
+    # Create a CloudWatch Alarm for CPU Utilization
     cloudwatch_client.put_metric_alarm(
-        AlarmName=f"{PREFIX}-scale-up-alarm",
-        ComparisonOperator='GreaterThanThreshold',
+        AlarmName=f"{PREFIX}-cpu-utilization-alarm",
+        ComparisonOperator='GreaterThanOrEqualToThreshold',
         EvaluationPeriods=1,
-        MetricName='RequestCountPerTarget',
-        Namespace='AWS/ApplicationELB',
-        Period=30,  # Short evaluation period for quick scaling up
+        MetricName='CPUUtilization',
+        Namespace='AWS/EC2',
+        Period=60,
         Statistic='Average',
-        Threshold=50,  # Lower threshold for scaling up faster
+        Threshold=20.0,
         ActionsEnabled=True,
-        AlarmActions=[sp_up],
-        AlarmDescription='Scale-up alarm',
+        AlarmActions=[sp_arn],
+        AlarmDescription='Alarm to scale out/in based on CPU utilization',
         Dimensions=[{
             'Name': 'AutoScalingGroupName',
             'Value': f"{PREFIX}-asg"
         }],
-        Unit='Count'
+        Unit='Percent'
     )
 
-    print(f"Scale-up alarm created")
-
-    # Create CloudWatch Alarms for scaling down
-    cloudwatch_client.put_metric_alarm(
-        AlarmName=f"{PREFIX}-scale-down-alarm",
-        ComparisonOperator='LessThanThreshold',
-        EvaluationPeriods=2,  # Longer evaluation period for slower scaling down
-        MetricName='RequestCountPerTarget',
-        Namespace='AWS/ApplicationELB',
-        Period=120,  # Longer period to prevent frequent scale-down actions
-        Statistic='Average',
-        Threshold=10,  # Higher threshold to delay scaling down
-        ActionsEnabled=True,
-        AlarmActions=[sp_down],
-        AlarmDescription='Scale-down alarm',
-        Dimensions=[{
-            'Name': 'AutoScalingGroupName',
-            'Value': f"{PREFIX}-asg"
-        }],
-        Unit='Count'
-    )
-
-    print(f"Scale-down alarm created")
+    print(f"CPU Utilization alarm created")
 
 # Main function
 def main():
@@ -411,11 +381,11 @@ def main():
 
     # Scaling Policies
     print("Creating Scaling Policies...")
-    sp_up, sp_down = put_scaling_policies(autoscaling_client, asg_arn)
+    sp = put_scaling_policy(autoscaling_client, asg_arn)
 
     # CloudWatch Alarms
     print("Creating CloudWatch Alarms...")
-    create_cloudwatch_alarms(cloudwatch_client, sp_up, sp_down)
+    create_cloudwatch_alarm(cloudwatch_client, sp)
 
     # Load Balancer DNS name
     response = elbv2_client.describe_load_balancers(