I am currently using AWS ECS to run a dockerized app on EC2 (t3.small instance). When I look at my cluster metrics in the console, it doesn't match at all what I can see on the EC2 instance metrics dashboard.
Here is the CPU utilization from ECS dashboard :
And from EC2 :
What can explain such a difference ? Could it be because of the ECS agent ?
Related
I am trying to setup AWS Nitro Enclave with ECS using AWS Cloudformation but I am struggling with assigning a launch template to an ECS service.
As far as I know, we can specify a launchType with the value of EC2 while creating the ECS Service but there is no way to manipulate the launch parameters.
Any help with examples will be appreciated.
The Nitro Enclave is part of the EC2 server. An ECS service is just a docker container running on the EC2 server. The EC2 server has to already be up and running (with things like Nitro Enclave already configured) before the ECS service is started on the server. The launchType parameter of the ECS Service just specifies if it should run on Fargate or EC2.
You can't configure your cluster's EC2 servers through an ECS service configuration. You would configure the EC2 servers in the ECS cluster through the cluster's Capacity Provider configuration. Specifically, since you are using EC2 instead of Fargate, you would need to configure the capacity provider with an EC2 auto-scaling group which is configured with an EC2 launch template that handles the Nitro Enclave setup.
To be clear, I've never heard of anyone using Nitro Enclaves with ECS, and I don't think you can actually run ECS services inside the Nitro Enclave. At most you could have ECS services running on the same server that also has a Nitro Enclave running some other process.
I have an ECS cluster - EC2-based built using Terraform. The Autoscaling group for this cluster has been configured that is having User-Data. Now, I want to migrate this ECS cluster from EC2 to Fargate. How I can migrate/mention user-data when I'm defining Autoscaling configuration for Fargate?
How I can migrate/mention user-data
You don't. User data is only for EC2 instances, and in Fargate you have no control over them. You have to abandon your user-data, as it has no use in you Fargate.
I'm using Is Amazon Elastic Kubernetes Service, I need to run fargate service on the Spot node.
Is it possible for EKS? Currently, I can find information about ECS only. So what steps I should follow to achieve this?
Fargate for EKS does not support spot instance yet. You can upvote here for the feature.
In the documentation it is mentioned
With AWS Fargate, there are no upfront costs and you pay only for the
resources you use. You pay for the amount of vCPU, memory, and storage
resources consumed by your containerized applications running on
Amazon Elastic Container Service (ECS) or Amazon Elastic Kubernetes
Service (EKS).
reference: https://aws.amazon.com/fargate/pricing/
This shows that Fargate Spot should work just fine for AWS EKS
From what I've read so far:
EC2 ASG is a simple solution to scale your server with more copies of it with a load balancer in front of the EC2 instance pool
ECS is more like Kubernetes, which is used when you need to deploy multiple services in docker containers that works with each other internally to form a service, and auto scaling is a feature of ECS itself.
Are there any differences I'm missing here? Because ECS is almost always a superior choice to go with if they work as I understand.
You are right, in a very simple sense, EC2 Autoscaling Groups is a way to add/remove (register/unregister) EC2 instances to a Classic Load Balancer or Target Groups (ALB/NLB).
ECS has two type of scaling as does any Container orchestration platform:
Cluster Autoscaling: Add remove EC2 instances in a Cluster when tasks are pending to run
Service Autoscaling: Add/remove tasks in a service based on demand, uses Application AutoScaling service behind the scenes
I think you have 2 scaling
1 for ec2 instance
1 for ecs task
So I think flow goes like
You get more requests
Your tasks need more resources (cpu/memory)
Your ecs task autoscaling kicks in and creates more task
your ec2 autoscaling also kicks in and creates more ec2
Questions
your ecs needs to know newly launched ec2 (from ec2 autoscaling group) is the host that it can run on (how?)
I want the number of ec2 instance starts from one.
I think one instance is already running in the ecs cluster
Do I make ec2 autoscaling group start from 0?
ec2 autoscaling group has pricing option to use spot instance, but I didn't see such option when I created ecs cluster instances. To be clear, can I make ecs cluster with 0 ecs-instance, and let ec2 autoscaling group starts with 1 instance?
Your ecs task autoscaling kicks in and creates more task
your ec2 autoscaling also kicks in and creates more ec2
Your ECS task scale if there is a memory so fine it will scale and launch new container, if not enough memory then it will not launch an instance, you need to configure cloud watch alarm to scale ECS cluster based on the task scaling.
Tutorial: Scaling Container Instances with CloudWatch Alarms
your ecs needs to know newly launched ec2 (from ec2 autoscaling group)
is the host that it can run on (how?)
ECS agent registers the new instance with the same cluster, and the new task can be placed in any instance that have available resources to handle and launch the container.
I want the number of ec2 instance starts from one. I think one
instance is already running in the ecs cluster Do I make ec2
autoscaling group start from 0?
You should start from 1 otherwise no container will launch and will throw error no instance found in the cluster. if you do not want run container for now then you can start from 0.
ec2 autoscaling group has pricing option to use spot instance, but I
didn't see such option when I created ecs cluster instances. To be
clear, can I make ecs cluster with 0 ecs-instance, and let ec2
autoscaling group starts with 1 instance?
You can read about spot ECS cluster instance here.
Amazon ECS is a highly scalable, high performance, container
management service that supports Docker containers and allows you to
run applications on a managed cluster of Amazon EC2 instances easily.
ECS already handles the placement and scheduling of containers on EC2
instances. When combined with Spot fleet, ECS can deliver significant
savings over EC2 on-demand pricing.