Remove wait for shutting-down instances

During cluster deletion, remove wait for shutting-down instances.
The shutting-down state is not recoverable, and instances in this state are not billed.
This change will fix the situation of cluster deletion failure when termination gets longer for some instance types

Ref. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-lifecycle.html

Signed-off-by: Luca Carrogu <[email protected]>

CHANGELOG.md

@@ -6,6 +6,8 @@ CHANGELOG
 
 **BUG FIXES**
 - Fix DRA configuration to make `AutoExportPolicy` and `AutoImportPolicy` optional.
+- Consider Compute fleet clean-up completed during cluster deletion when instances are either in shutting-down or terminated state.
+  This is to avoid cluster deletion failure for instance types with longer termination cycles.
 
 3.9.0
 ------

cli/src/pcluster/resources/custom_resources/custom_resources_code/cleanup_resources.py

@@ -117,33 +117,12 @@ def _terminate_cluster_nodes(event):
                         logger.error("Failed when terminating instances with error %s", e)
                         completed_successfully = False
                         continue
-            logger.info("Sleeping for 10 seconds to allow all instances to initiate shut-down")
-            time.sleep(10)
-
-        while _has_shuttingdown_instances(stack_name):
-            logger.info("Waiting for all nodes to shut-down...")
-            time.sleep(10)
-
-        # Sleep for 30 more seconds to give PlacementGroups the time to update
-        time.sleep(30)
-
-        logger.info("Compute fleet clean-up: COMPLETED")
+        logger.info("Compute fleet clean-up: COMPLETED. Instances are either in shutting-down or terminated state")
     except Exception as e:
         logger.error("Failed when terminating instances with error %s", e)
         raise
 
 
-def _has_shuttingdown_instances(stack_name):
-    ec2 = boto3.client("ec2", config=boto3_config)
-    filters = [
-        {"Name": "tag:parallelcluster:cluster-name", "Values": [stack_name]},
-        {"Name": "instance-state-name", "Values": ["shutting-down"]},
-    ]
-
-    result = ec2.describe_instances(Filters=filters)
-    return len(result.get("Reservations", [])) > 0
-
-
 def _describe_instance_ids_iterator(stack_name, instance_state=("pending", "running", "stopping", "stopped")):
     ec2 = boto3.client("ec2", config=boto3_config)
     filters = [