I have an EC2 instance which is in us-east-1b and is running the flink jobmanager, which is responsible for coordinating work across multiple taskmanagers via RPC, and history server. I can see from netstat that the jobmanager is listening on
:::6123 for incoming taskmanager connections.
I have an auto scaling group which will run up an EC2 instance into the same az, subnet and security group as the EC2 instance.
I'm using that ASG as a capacity provider for ECS tasks. I'm then trying to run up a task in ECS that runs the taskmanager and uses that ASG.
The taskmanager starts up, but won't connect to the jobmanager:
2021-09-28 13:52:08,651 INFO org.apache.flink.runtime.taskexecutor.TaskExecutor  - Could not resolve ResourceManager address akka.tcp://firstname.lastname@example.org:6123/user/rpc/resourcemanager_*, retrying in 10000 ms: Could not connect to rpc endpoint under address akka.tcp://email@example.com:6123/user/rpc/resourcemanager_*.
I've ssh-d onto the instance run up by the ASG and confirmed that I can curl the jobmanager on
ip-xxx-xx-x-xxx.ec2.internal:8081 - it works. So I know that the taskmanager instance can see the jobmanager instance.
- The taskmanager and jobmanager are in the same VPC, the same AZ, the same subnet and the same security group
- The security group allows all inbound traffic from sources in the same security group
- The security groups allows all outbound traffic to any destination
- The jobmanager is running on an EC2 instance manually created
- The taskmanager is running on an EC2 instance created as part of an ASG by ECS. The taskmanager runs in a container on ECS
- I can curl the jobmanager from the taskmanager node
- The taskmanager and jobmanager communicate over RPC
- The taskmanager won't resolve the address to the jobmanager
Why won't my task connect? I've also tried the public IP (v4) and the private IP (v4).