usually you want to a release to be all the way deployed or all the way rolled back not sitting in some half state. because it gets really hard to reason about

usually you want to a release to be all the way deployed or all the way rolled back not sitting in some half state. because it gets really hard to reason about the state of mutable resources like databases and storage that is being written to by two different versions of the application simultaneously. in this situation pushing on with the deploy or rolling it all back are valid options. however everyone knows rollback are always more difficult than deploys