recluster
Clustering library with support for zero-downtime reloading
herd
A simple wrapper over node cluster for zero-downtime reloads
cluster-master-ext
A module for taking advantage of the built-in `cluster` module in node v0.8+, enables rolling worker restarts, resizing, repl, events, configurable timeouts, debug method. Zero downtime deploy of workers. Extended version of cluster-master
rollstarts
A simple Node.js package to implement zero-downtime rolling restarts within your application.