Support for specifying the MyriaX port in configuration is a recent change we've made ("database_port" in the deployment file), and it needs to be propagated to the docs. Can you open an issue pointing to wherever you saw this? Also -- we also recently changed the default Myria port to 5432 to conform to the default that Postgres uses. We should update the documentation wherever you see a 5401 as well.
From @BrandonHaynes
Applies to myriaX.markdown.