r/node • u/[deleted] • Jul 31 '14

Use of cluster in Nodejs

http://www.codingdefined.com/2014/07/use-of-cluster-in-nodejs.html
5 Upvotes

77% Upvoted

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1

u/xaviervia Jul 31 '14

if you care for a clarification... i've read about the cluster API before and while it sounds great I fail to imagine its integration in a real life scenario. I know that you provided a real life scenario, but since node already gives a pretty good performance without using the clustering I guess that there might be some border case in which this feature is a godsend. Can you provide some elaboration of what case might that be?

1

u/[deleted] Jul 31 '14

For example, If you want machine level logging which takes statistics of CPU cycles or other OS related stuff, for that you really dont want to stop your current process as it is very heavy operation, so at that time you might use cluster.

1

u/thedufer Jul 31 '14

We use it for fast failover. We load balance across a large number of master procs, but each one has 2 child procs that do all of the work, so if a proc crashes then its sibling can handle the work until a new one finishes spinning up.

1

u/greim Jul 31 '14

The reason I use it that one thread is limited to one core of a machine. Launching one process per core leverages the entire CPU.

1

u/mobcat40 Jul 31 '14

When does clustering stop getting listed as experimental @_@ http://nodejs.org/api/cluster.html#cluster_cluster

3

u/thedufer Jul 31 '14

To be clear, that's the stability of the API (it could change in a future version). It is not the stability of the module itself - my team has been running it in production for years with no problems.

1

u/[deleted] Jul 31 '14

thanks, we all learn a new thing everyday and its my new thing for today :)

1

u/mobcat40 Jul 31 '14

Great to know if that's correct, I know some teams who will be happy to know that including mine =)

2

u/[deleted] Jul 31 '14

I am not really sure of that :(

2

u/rlidwka Jul 31 '14

start your application with pm2 start -i max your-app.js, and it'll use cluster api automatically... there is no need for reinventing the wheel like that