Try setting JVM system params. For example, an early demo that I hacked up looked like this. It isn't on EC2, but I don't think that EC2 is really your problem. Hack out the stuff you don't care about and omit the -J if not using sbt.
Instance 1: sbt -J-Dakka.remote.netty.tcp.hostname=localhost -J-Dakka.cluster.seed-nodes.0=akka.tcp://CloudObjects-core@localhost:2552 -J-Dcom.sun.management.jmxremote.port=9999 -J-Dcom.sun.management.jmxremote.authenticate=false -J-Dcom.sun.management.jmxremote.ssl=false -J-Dcloudobjects.journalLocation=akka.tcp://CloudObjects-core@localhost:2552/user/journal run Instance 2: sbt -J-Dakka.remote.netty.tcp.hostname=localhost -J-Dakka.remote.netty.tcp.port=2553 -J-Dakka.cluster.seed-nodes.0=akka.tcp://CloudObjects-core@localhost:2552 -J-Drole=backend -J-Dcloudobjects.journalLocation=akka.tcp://CloudObjects-core@localhost:2552/user/journal run -- >>>>>>>>>> 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 akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.