When using pm2 cluster there's a pretty severe warning saying you shouldn't use it in production, nor for load balancing, use nginx instead. Unfortunately that's exactly how I planned to use PM2. Is it really not intended to be used for that purpose or is it just not completely ready yet?
The nodejs cluster (0.10) has a lot of issues and is not safe to use in production! You may want to give a try with 0.11, there were some improvements.
This feature has not anything to do with pm2, it's in fact directly related to node cluster module.
来源：https://stackoverflow.com/questions/28083959/nodejs-pm2-cluster-mode-for-load-balancing