问题
Heroku can run
Web Dynos
and
Worker Dynos
so that Web Dynos take care of routes
and worker Worker Dynos take care of processing works.
Since there is a unit of Dyno,
It seems using Node.js cluster module is meaningless to me on Heroku.
Because Node.js cluster module is to use all cores of server CPU
and Dyno seems virtual unit of CPU core to me.
Am I right? Or is it still worth to run a node.js app with cluster module?
回答1:
I've found that it actually worth to use cluster module
because each dyno has 4 CPU cores.
Reference: http://www.quora.com/Heroku/How-powerful-is-one-Heroku-dyno
回答2:
This is an old question, thought I should update to a more complete answer.
According to this table on their documentation
- 1X Dynos have 1 cluster
- 2X Dynos have 2 clusters
- PX Dynos have 12 clusters
So, assuming that you are using 1X dynos, it won't be necessary to implement clusters. If you are using the other ones, it is a good idea to do so.
The number of clusters can be found on the WEB_CONCURRENCY environment variable.
回答3:
That's very good news to me, i assumed that a dyno is just one core. I actually wrote and open sourced a small but very nicely made cluster setup (backed by redis and job queue)
https://bitbucket.org/jeveloper/nodejscluster
来源：https://stackoverflow.com/questions/11410226/running-node-js-app-with-cluster-module-is-meaningless-in-heroku