I created an NLB and a fargate service.
Then i create a target group with "ip" of my ecs instance.
When i now add a fargate ip to my target group, it works, but how does the scaling work? Suppose ecs has to scale out, i will have to register another ip, but i want it to scale automatically.
Let us say one task is added. How does the network load balancer the new task ip without me manually adding it?
I do not get, how the link is between the nlb and the service of ecs. Does amazon does add targets implicitly?
Instead of manually registering the IP of your Fargate task with the target group, you are supposed to configure the ECS service with knowledge of the load balancer you want to use. The ECS service will then automatically register every task that it creates as part of deployments and auto-scaling.
Related
I would like to use an NLB and target an ecs fargate service, but i cannot find any option to use ecs service as target group. Is it even possible?
When i create a service in a fargate cluster, i can only use application load balancer as option.
The process of using NLB with ECS for Fargate is explained in AWS Docs for Fargate:
Creating a Network Load Balancer
Background
Current State: I currently have a nlb that routes to an nginx server running on an ec2 instance.
Goal
I am trying to replace the nginx ec2 instance with a fargate service that runs nginx.
I would like to keep the current nlb and set the fargate cluster as the target group for the existing nlb.
Problem
according to aws documentation, aws ecs fargate cluster service supports loadbalancing with nlb or alb: https://docs.aws.amazon.com/AmazonECS/latest/userguide/service-load-balancing.html
when I try to deploy the nginx task, in the load balancing section,
there is only an option to select an existing alb or create a new
alb.
I tried changing the task protocol to TCP and UDP--regardless of
the protocol, when I try to deploy the task as a service, the only
load balancer option is still application load balancer.
Question
How do I load balance to a fargate cluster service task using an nlb? Am I missing a specific setting somewhere?
If you cannot set the fargate cluster as a target group for an nlb directly, would it be reasonable to route traffic from an nlb to an alb and then set the alb target group as a fargate cluster?
You can absolutely use an NLB with an ECS Fargate service. I've done this before many times. My guess is you are simply encountering a bug in the AWS web UI. I've always used Terraform to deploy this sort of thing. I just checked in the ECS web UI, and on the 2nd step of creating a new ECS service I get the option of using a Network Load Balancer:
If your view doesn't look like that, try switching from the "New ECS Experience" in the UI which is still fairly beta and missing a lot of features.
I just went back and checked, and in the new ECS UI they are currently missing the option to select an NLB, so you have to continue using the old version of the UI for now until they fix that. I suggest continuing to use the old UI until they phase it out, because the new ECS UI is still missing a lot of features.
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 have a Fargate Service running in AWS. I use it to run multiple tasks. Some of the tasks connect to an RDS database to query the database.
How can I add the Fargate Service to my inboard rules of a Security Group for the RDS database? - Is there a way to associate an Elastic IP with the Fargate Cluster?
Might have misunderstood something here... But the ECS allows you specify a security group at the service level.
Go to https://docs.aws.amazon.com/cli/latest/reference/ecs/create-service.html
And search for the --network-configuration parameter
So surely you just need to set the source on your inbound rule of the RDS security group to be that security group ID?
Fargate doesn't support associating Elastic IPs with clusters. Clusters which runs in Fargate mode operate on instances which are not yours, it's the opposite of classic ECS stacks. That means you can't manage networking of host instances.
There is a way to associate IP with stack by having a Network Load Balancer in front of cluster. Then you could add a rule which allows connect your cluster through NLB.
In the above architecture (source: http://media.amazonwebservices.com/AWS_Web_Hosting_Best_Practices.pdf), The application server cluster belong to an autoscaling group. But is load balanced by a software loadbalancer (like nginx or HAProxy). My question is if the how the nodes in autoscaling group registers itself automatically with the loadbalancer(As I understand Elastic loadbalancer has this capability builtinm which may not be case for nginx or HAProxy)
When you create Autoscaling group in AWS, you connect it with launch configuration which is responsible for launching new instances of the specific image, so each instance is automatically assigned to autoscaling group.
In the next step, you register your load balancer with your autoscaling group, so load balancer can use any of the instances that belongs to the group.
Please check this tutorial http://docs.aws.amazon.com/AutoScaling/latest/DeveloperGuide/as-register-lbs-with-asg.html
Zoran
There's a great blog post on how to do this using PHP app.
http://www.kloppmagic.ca/auto-scaling-with-haproxy/
Of course you could use other tools like consul and service discovery baked into your image.