Bootstrap on GCE

Akka Libraries Akka Cluster
1

I (think) I would like to use akka-management-cluster-bootstrap on GCE, however AFAICT there is no DNS record for all instances of a managed instance group. I can call GCP APIs, however I don’t know where to start to define a custom discovery mechanism.

Background: I would like to implement a task queue an an app that’s autoscaled, and to ensure that the same task doesn’t get executed on two nodes simultaneously I thought of having the nodes form a cluster and specifying that I want a single instance of an actor on them. I’ve used akka actors before (though not typed, which I might prefer to use), but not in a cluster. I’m open to other ways of solving the objective too.

2

Bootstrap can work with any of the service discovery implementations (currently DNS, Consul, AWS API, Kubernetes API, Marathon API, etc). If you can’t get a DNS record then implementing a service discovery mechanism for GCE is a good idea, we have one for the AWS API.

Would you want to give it a try? Here is the AWS one for reference: https://github.com/akka/akka-management/blob/master/discovery-aws-api-async/src/main/scala/akka/discovery/awsapi/ecs/AsyncEcsSimpleServiceDiscovery.scala they are usually quite straight forward to implement.

You can start off by copying one of the other service discovery projects in Akka Management e.g. https://github.com/akka/akka-management/tree/master/discovery-aws-api-async/

Once you get started you can raise a WIP PR to ask any questions / get guidance on whether you’re on the right track.

3

TBH I would probably implement it in my application codebase, at least initially. Once it’s working I can probably contribute it.

Thanks for the pointer.

Do you think my broader approach is right though?

4

Yes, it is the equivalent of the AWS API discovery mechanism, it would be great to have GCE API as well.

5

After thinking about the the underlying problem more, I decided that I don’t really need a task queue after all. Perhaps one would make things more robust, but it’s not worth it right now.

Thanks for the help anyway