Hey Gustavo, I'm running the following command: $ docker run -it --name master -h master -e "SLAVES=1" gustavonalle/infinispan-server-domain:9.0.0.Alpha2 And seeing this WARN message: https://gist.github.com/galderz/895dd3bc60ddcd2065eb5c4680681d0d I don't think functionality is affected but preferable method for Netty's event loop could not be found. Does this ring a bell? Cheers, -- Galder Zamarreño Infinispan, Red Hat