AWS ASG Warm Pools Vs EKS Over-Provisioning - amazon-web-services

I can see we can over-provision in EKS for low latecy & I find "ASG Warm pools" similar. My question is, how relevant "ASG Warm Pools" are instead of "Over-provisioning" in AWS EKS?
Thanks.

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How can I understand `Nodes` in EKS Fargate?

I deployed a EKS cluster and a fargate profile. Then I deployed a few application to this cluster. I can see these fargate instances are launched.
when I click each of this instance, it shows me some information like os, image etc. But it doesn't tell me the CPU and memory. When I look at fargate pricing: https://aws.amazon.com/fargate/pricing/. It is calculated based on CPU and Memory.
I have used ECS and it is very clear that I need to provision CPU/Memory in service/task level. But I can't find anything in EKS.
How do I know how much resources they are consuming?
With Fargate you don`t have provision, configure or scale virtual machines to run your containers so that they become fundamental compute primitive.
This solution model is called serverless where you are being charged for only the compute resources and storage that are need to execute some piece of your code. It does not mean that there are not server involved in this, it just you don`t need to care about those.
To monitor there those you can use CloudWatch. Below documents describe how this can be achieved:
How do I troubleshoot high CPU utilization on an Amazon ECS task on
Fargate?
How can I monitor high memory utilization for Amazon ECS tasks on
Fargate?
It is worth to mention that Fargate is just a launch type for ECS (Another one is EC2). Please have a look at the diagram in this document for clear image of how those are connected. The CloudWatch metrics are collected automatically for Fargate. If you are using the AKS with Fargate you can monitor them with usage of metrics-addon or prometheus inside your kubernetes cluster.
Here's an example of monitoring Fargate with Prometheus. Notice that it scrapes the metrics from CloudWatch.

Does AWS ECS Control Plane i.e Cluster cost any thing?

On looking at the EKS Pricing page, its very clear that the cluster i.e control plane as of today costs $.10/hour. Quote from - https://aws.amazon.com/eks/pricing/
You pay $0.10 per hour for each Amazon EKS cluster that you create.
But on looking at ECS pricing page - https://aws.amazon.com/ecs/pricing/, I am not able to figure out the cluster i.e control plane cost. So before creating an ECS cluster and leaving it there irrespective of usage, I want to know how I will be billed.
Please share your thoughts!!!!
Also, my understanding is, for EKS cluster, I will be charged for the cluster irrespective of the usage i.e the cluster is used for deployments/pods/services etc or just left doing nothing. Please correct if wrong.
No, ECS does not have a control plane/cluster fee. You only pay for the EC2 or Fargate resources ECS runs your containers on.
Your understanding about the EKS cluster costs is correct.
Note: There are other fees an ECS cluster can generate, such as CloudWatch Logs and Metrics fees, but that's true for all the AWS compute services, including EKS, Elastic Beanstalk, Lambda, etc.

How to shutdown EC2 instances backed by ECS to save the cost for staging/QA

We have hosted a docker container on AWS ECS with EC2 instances and would like to terminate/showdown these EC2 instances in the night & weekend for Staging/QA to save the cost.
Thanks in advance :)
The AWS Instance Scheduler is a simple AWS-provided solution that enables customers to easily configure custom start and stop schedules for their Amazon Elastic Compute Cloud (Amazon EC2) and Amazon Relational Database Service (Amazon RDS) instances. The solution is easy to deploy and can help reduce operational costs for both development and production environments.
https://aws.amazon.com/solutions/implementations/instance-scheduler/
If you run the instances in an AutoScaling Group (ASG) , you could use scheduled policy to set a desired capacity of the ASG to zero for the off-peak times. A second policy would start it for work time.
Alternative would be setup a CloudWatch Event scheduled rule using cron with target of lambda function. The function would do same as the scaling policy. But because this is lambda function, you could also do some other things there. For example, do some pre-shutdown checks or post-shutdown cleanup.
This will work, because if your tasks run in service, ECS will automatically relaunch your tasks when the instances are back.
You could also manage the number of tasks using scheduling capability of Amazon ECS.

AWS ECS Tasks - when in the state machine do charges begin?

I use AWS Elastic Container Service (ECS) run-task to schedule tasks using both EC2 and Fargate, and I use stop-task to cancel some of them.
The state machine seems to be PROVISIONING -> PENDING -> ACTIVE. I know for sure that if I stop-task during ACTIVE I am charged at least a 1-minute minimum. I am guessing that if I stop-task during PROVISIONING I am not charged the 1-minute minimum. I am not sure about PENDING.
I am not sure about this and have been unable to find any documentation on the AWS site. Does anyone know? Can anyone point me to documentation that shows the answer one way or the other?

Scaling ECS EC2 instances when a task cannot be placed

I am using an ECS cluster for Jenkins agents/slaves with the Jenkins ECS plugin.
The plugin places a ECS Task when a job requests a build-node. Now I want to scale the EC2 instances in a Autoscaling Group associated with the ECS Cluster according to the demand.
The jenkins is often idle. In this case, I do not want there to be any instances in the autoscaling group.
If a node (and therefore an ECS task) is requested and cannot be placed, I want to add an EC2 instance to the autoscaling group.
If an instance is idle and shortly before an billing hour, I want that instance to be removed.
The 3. point can be accomplished by a cronjob on the EC2 instances that regularly checks if the conditions are met and removes the EC2 instance.
But how can I accomplish the 2. point? I am unable to create a cloudwatch alarm that triggers, if a task cannot be placed.
How can I accomplish this?
A rather hacky way to achieve this: You could use a Lambda function to detect when a service has runningCount + pendingCount < desiredCount for more than X seconds. (I have not tested this yet.)
Similar solutions are proposed here.
There does not seem to be a proper solution to scale only when tasks cannot be placed. Maybe AWS wants us to over-provision our clusters, which might be good practice for high availability, but not always the best or cheapest solution.
When a task cannot be placed it means that placing that task in your ECS cluster would exceed either your MemoryReservation or CPUReservation. You could set up Cloudwatch alarms for one or both of these ECS metrics and an auto scaling policy that will add and remove EC2 instances in your ECS cluster.
This, in combination with an auto scaling policy that scales your ECS services on the ecs:service:DesiredCount dimension should be enough to get you adding the underlying EC2 instances your ECS cluster requires.
For example your ScalingPolicy for an ECS Service might be "when we're using 70% of our allotted memory for this service, add 2 to the DesiredCount". After adding 1 service task, your ECS Cluster MemoryReservation metric might bump up past an "80" threshold, at which point a Cloudwatch alarm would trigger for some threshold on ECS MemoryReservation, with an auto scaling policy adding another EC2 node, on which the 2nd task could now be placed.
For those arriving after January 2020, the way to handle it now is probably Cluster Auto Scaling as documented here: "Amazon ECS cluster auto scaling" with more info here: "Deep Dive on Amazon ECS Cluster Auto Scaling)".
Essentially, ECS now handles most the heavy lifting. Not all, or I wouldn't be here looking for an answer ;)
For point 2, one way to solve this would be to autoscale when there is not enough cpu units for placing a new jenkins slave.
You should use the cpu reservation metric on the cluster to scale.
http://docs.aws.amazon.com/AmazonECS/latest/developerguide/cloudwatch-metrics.html#cluster_reservation