I've created a simple task to print a hello world. I've created a ECR image, docker compose and ecs-params.yml.
I get the cloudwatch log for the print, but the task keeps launching every minute, which I guess it's due to REPLICA service type.
How can I stop this from happening, I want to launch this Fargate task ONLY from a lambda, and when it finishes I don't it to be relaunched.
Thanks in advance
If you want a one-shot / one-off / standalone task to be launched by ECS and have it run until it finishes, you wouldn't use an ECS service definition but merely a task.
You can run tasks on their own without packaging as an ECS service.
See: https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs_run_task.html
If you are using the ECS CLI, then there is also ecs-cli compose create. So, you would use that call and not the one also creating an ECS service along with it.
You can then use AWS Lambda and send an ecs:RunTask AWS API call to invoke/start the ECS task.
Related
I have a cluster running two services, a web app, and a message queue handler. The app has autoscaling configured, but the queue handler does not. There's also a couple of scheduled tasks that run as well.
If I run a task manually using the cli (aws ecs run-task), the task works properly at first, then then after about 5 minutes loses the ability to make outbound connections.
From looking at the scaling logs, it doesn't look like autoscaling would be causing this issue.
Let us say I am defining a task definition in AWS Fargate, this task definition would be used to start up tasks that involve a multi-container application regarding 2 web servers. How many task definitions would I need, how many tasks would I pay for and how many services are create?
I have read a lot of documentation, but it does not click for me. Is there anyone who can explain the correlation between: task definitions, task/s, Docker containers, services and ECS Fargate clusters?
A task definition is a specification. You use it to define one or more containers (with image URIs) that you want to run together, along with other details such as environment variables, CPU/memory requirements, etc. The task definition doesn't actually run anything, its a description of how things will be set up when something does run.
A task is an actual thing that is running. ECS uses the task definition to run the task; it downloads the container images, configures the runtime environment based on other details in the task definition. You can run one or many tasks for any given task definition. Each running task is a set of one or more running containers - the containers in a task all run on the same instance.
A service in ECS is a way to run N tasks all using the same task definition, and keep those N tasks running if they happen to shut down unexpectedly. Those N tasks can run on different instances in EC2 (although some may run on the same instance depending on the placement strategy used for the service); on Fargate, there are no instances and the tasks "just run", so you don't have to think about placement strategies. You can also use services to connect those tasks to a load balancer, so that requests from a client inside or outside of AWS can be routed evenly cross all N tasks. You can update the task definition used by a service, which will then trigger a rolling update (starting up and shutting down running tasks) so that all running tasks will be using the new version of the task definition after the deployment completes. This is used, for example, when you create a new container image and want your service to be updated to use the latest version.
A service is scoped to a cluster. A cluster is really just a name. Different clusters can have different IAM policies and roles, so that you can restrict who can create services in different clusters using IAM.
The question seems simple enough. I have a bunch task definitions and a cluster in my CloudFormation template. When setting up manually I would create a task based on any definition and provide it with a CRON definition. It would then start to run.
I can't seem to find this option in CF? I found service but this only works for tasks that run indefinitely, which mine are not (they run once per day for approx. 10-20 minutes).
After some research I found out about AWS::Events::Rule which people seem to only use in conjunction with Lambda which I do not. I was unable to find any example that referenced FARGATE tasks so I'm not sure it's even possible.
If anyone has any examples of running tasks in CRON using CF, that would be great.
I think that ECS scheduled tasks (cron) would suit you:
Amazon ECS supports the ability to schedule tasks on either a cron-like schedule or in a response to CloudWatch Events. This is supported for Amazon ECS tasks using both the Fargate and EC2 launch types.
This is based on CloudWatch Events which can be used to schedule many things, not only lambda.
To setup it using CloudFormation you can use AWS::Events::Rule with the target of AWS::Events::Rule EcsParameters
I am building a data pipeline for batch processing. And I find that Spring Cloud Data Flow is a quite attractive framework to use. Without much knowledge in SCDF and Kubernetes, I am not sure whether it is possible to conditionally launch a Spring Cloud Task on a specific machine.
Suppose I have two physical servers that are for running the batch process (Server A and Server B). By default, I would like my Spring cloud task to be launched on Server A. If the Server A is shut down, the task should be deployed on server B. Can Kubernetes / SCDF handle this kind of mechanism? I am wondering whether the nodeselector is the thing that I should look into.
Yes, you can pass deployment.nodeSelector as a deployment property when launching the task.
The deployment.nodeSelector is a Kubernetes deployment property and hence, you need to pass something like this:
task launch mytask --properties "deployer.<taskAppName>.kubernetes.deployment.nodeSelector=foo1:bar1,foo2:bar2"
You can check the list of supported Kubernetes deployer properties here
I have a batch process, written in PHP and embedded in a Docker container. Basically, it loads data from several webservices, do some computation on data (during ~1h), and post computed data to an other webservice, then the container exit (with a return code of 0 if OK, 1 if failure somewhere on the process). During the process, some logs are written on STDOUT or STDERR. The batch must be triggered once a day.
I was wondering what is the best AWS service to use to schedule, execute, and monitor my batch process :
at the very begining, I used a EC2 machine with a crontab : no high-availibilty function here, so I decided to switch to a more PaaS approach.
then, I was using Elastic Beanstalk for Docker, with a non-functional Webserver (only to reply to the Healthcheck), and a Crontab inside the container to wake-up my batch command once a day. With autoscalling rule min=1 max=1, I have HA (if the container crash or if the VM crash, it is restarted by AWS)
but now, to be more efficient, I decided to move to some ECS service, and have an approach where I do not need to have EC2 instances awake 23/24 for nothing. So I tried Fargate.
with Fargate I defined my task (Fargate type, not the EC2 type), and configure everything on it.
I create a Cluster to run my task : I can run "by hand, one time" my task, so I know every settings are corrects.
Now, going deeper in Fargate, I want to have my task executed once a day.
It seems to work fine when I used the Scheduled Task feature of ECS : the container start on time, the process run, then the container stop. But CloudWatch is missing some metrics : CPUReservation and CPUUtilization are not reported. Also, there is no way to know if the batch quit with exit code 0 or 1 (all execution stopped with status "STOPPED"). So i Cant send a CloudWatch alarm if the container execution failed.
I use the "Services" feature of Fargate, but it cant handle a batch process, because the container is started every time it stops. This is normal, because the container do not have any daemon. There is no way to schedule a service. I want my container to be active only when it needs to work (once a day during at max 1h). But the missing metrics are correctly reported in CloudWatch.
Here are my questions : what are the best suitable AWS managed services to trigger a container once a day, let it run to do its task, and have reporting facility to track execution (CPU usage, batch duration), including alarm (SNS) when task failed ?
We had the same issue with identifying failed jobs. I propose you take a look into AWS Batch where logs for FAILED jobs are available in CloudWatch Logs; Take a look here.
One more thing you should consider is total cost of ownership of whatever solution you choose eventually. Fargate, in this regard, is quite expensive.
may be too late for your projects but still I thought it could benefit others.
Have you had a look at AWS Step Functions? It is possible to define a workflow and start tasks on ECS/Fargate (or jobs on EKS for that matter), wait for the results and raise alarms/send emails...