Safe Process State Upgrades Through Static Analysis

Hot code loading allows changing the server code without any noticeable effects for clients. It is an integral part of the Erlang language and the BEAM runtime. Handling code change scenarios has to be developed into the application and requires care from the developer. This paper presents static analysis-based code checkers for detecting code errors which could impede performing hot code loads in Erlang applications. Our work analyses some specific erroneous patterns that impede a hot code load when migrating server states between code versions.