As I known, node.js can not be zero downtime if change the source code of javascript and restart to run (hot deployment). Even there are some solution can restart node.js automatically, but they are not real zero downtime restart. Just wonder due to dustjs has some basic logical function, if this can makes node.js (while no big change to controller/logic) can be zero downtime when hot deploy.
There is liveswap
which enables you to deploy and restart a new version of an app with zero downtime:
https://medium.com/node-js-javascript/f00ce09abb77
https://www.npmjs.org/package/liveswap
usage is pretty straightforward, a bit like forever
liveswap --start index.js
liveswap —-upgrade index.js