I have an ECS cluster where I place a container that runs as a daemon to monitor all other processes. However, I’m seeing this containers being killed by OOM from time to time without leaving a trace. I just happened to spot one of them being killed. This is causing some log duplication but I wonder if there is a way to trace these restarts because when I look on the ECS Cluster events, there are no information about this tasks being restarted by any means.
I know more from kubernetes so I would say an analogy here. When this happens on kubernetes you would see a RESTARTS
counter when you get information from all pods (kubectl get pods
) is there any way to find this information on AWS ECS tasks? I’m struggling to find on documentation
I identified the tasks, and also I identified the status of each tasks to gain more information, but I’m unable to find any hint that the process was restarted or killed before.
this is a task detail example
- attachments: []
attributes:
- name: ecs.cpu-architecture
value: x86_64
availabilityZone: us-east-2c
clusterArn: arn:aws:ecs:us-west-2:99999999999:cluster/dev
connectivity: CONNECTED
connectivityAt: '2023-01-24T23:03:23.315000-05:00'
containerInstanceArn: arn:aws:ecs:us-east-2:99999999999:container-instance/dev/eb8875fhfghghghfjyjk88c8f96433b8
containers:
- containerArn: arn:aws:ecs:us-east-2:99999999999:container/dev/05d4a402ee274a3ca90a86e46292a63a/e54af51f-2420-47ab-bff6-dcd4f976ad2e
cpu: '500'
healthStatus: HEALTHY
image: public.ecr.aws/datadog/agent:7.36.1
lastStatus: RUNNING
memory: '750'
name: datadog-agent
networkBindings:
- bindIP: 0.0.0.0
containerPort: 8125
hostPort: 8125
protocol: udp
- bindIP: 0.0.0.0
containerPort: 8126
hostPort: 8126
protocol: tcp
networkInterfaces: []
runtimeId: 75559b7327258d69fe61cac2dfe58b12d292bdb7b3a720c457231ee9e3e4190a
taskArn: arn:aws:ecs:us-east-2:99999999999:task/dev/05d4a402ee274a3ca90a86e46292a63a
cpu: '500'
createdAt: '2023-01-24T23:03:22.841000-05:00'
desiredStatus: RUNNING
enableExecuteCommand: false
group: service:datadog-agent
healthStatus: HEALTHY
lastStatus: RUNNING
launchType: EC2
memory: '750'
overrides:
containerOverrides:
- name: datadog-agent
inferenceAcceleratorOverrides: []
pullStartedAt: '2023-01-24T23:03:25.471000-05:00'
pullStoppedAt: '2023-01-24T23:03:39.790000-05:00'
startedAt: '2023-01-24T23:03:47.514000-05:00'
startedBy: ecs-svc/1726924224402147943
tags: []
taskArn: arn:aws:ecs:us-west-2:99999999999:task/dev/05d4a402ee274a3ca90a86e46292a63a
taskDefinitionArn: arn:aws:ecs:us-west-2:99999999999:task-definition/datadog-agent-task:5
version: 2
3
Answers
So, after debugging a lot within the little information AWS provides for this use case, I ended up doing a process to find the answer:
--desired-status STOPPED
and dump all to a json fileI could came up with a script to group and summarize the information but, since I only had to watch over 20 stopped tasks I ended up dumping the information in yaml format for easiness. I found two key properties on the output:
Note: This information would give you all events for a given service for at least the last hour. In my case it gave me 8 hours of events but AWS documentation only promises 1 hour https://docs.aws.amazon.com/AmazonECS/latest/developerguide/stopped-task-errors.html
I don’t think ECS tracks or exposes a restart counter for tasks. If you want to be notified of tasks restarting you can create an Event Bridge subscription.
You can use ECS Event with
EventBridge
and add any action like logging when such event happen.