There <https://groups.google.com/forum/#!searchin/akka-user/ec2$20seed$20nodes/akka-user/lBcl3WgEM_0/mocdn8-jmXsJ> are a <https://groups.google.com/forum/#!searchin/akka-user/ec2$20seed$20nodes/akka-user/_1oc9aEfEJw/zye9BSVKFccJ> number <https://groups.google.com/forum/#!searchin/akka-user/ec2$20seed$20nodes/akka-user/-rwF3t_OF4I/soogf_uHLgsJ> of threads <https://groups.google.com/forum/#!searchin/akka-user/ec2$20seed$20nodes/akka-user/rKS9jnaFvv8/_1ulsZQvfX0J> on how to deploy an akka cluster on ec2, and it seems straightforward to establish the list of potential members of a cluster (e.g. get the members in an auto scaling group, or a security group, or whatever), and these can be sensibly ordered (e.g. by launch time with IP being a tie-breaker) such that all hosts can agree on which one should be the "primary" seed node. Cluster(system).joinSeedNodes(primary, *[hosts other than current one]*) can then be used to get the cluster going. So far so good.
However, when the primary starts the application (after first launch, code deploy, or reboot), it has no idea if there's already a cluster running, or if it should indeed start a new cluster (keep in mind that a cluster may recently have been running, but it may have been shut down in the last 30 seconds so that helpful information you wrote to disk before restarting may be terribly out of date). *Assuming there is no network partitioning*, i *s Cluster(system).joinSeedNodes(myself, host2, host3, host4, ...) smart enough to check for and join an existing cluster if the other hosts are already running it, or does it always start a new one if the current machine is the first entry?* Previous answers <https://groups.google.com/d/msg/akka-user/rKS9jnaFvv8/lwW8pzLJ5xEJ> have left this precise point a little ambiguous. If not, what are some best practices for how to have the intended seed node start a new cluster if the cluster isn't running, but be smart enough to join the existing cluster if it's already there? *I do not want to use any external dependencies (= zookeeper) other than the AWS APIs from which I can get a canonical list of all the relevant hosts. * -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
