How do I get SocketCluster to restart on file change?

Question

I'm running http://socketcluster.io/ and I want to restart my workers whewnever a file changes. However, nodemon server.js fails as soon as it tries to restart with an endlessly-repeating wall of:

1445633138359 - Origin: Worker (PID 44372)
    [Error] Error: connect ECONNREFUSED /var/folders/fj/yzfd3_tn7xd0smz7j6s093mh0000gn/T/socketcluster/6879fe94-ed92-4188-b1d7-cb187a5ade4e_b68fcded6c/b0
    at Object.exports._errnoException (util.js:874:11)
    at exports._exceptionWithHostPort (util.js:897:20)
    at PipeConnectWrap.afterConnect [as oncomplete] (net.js:1063:14)
1445633138362 - Worker 0 exited - Exit code: 0

How can I safely restart SocketCluster to load the new changes?

PM2 will let you restart upon file changes with no downtime if you use clustering. — dandavis, Oct 23 '15 at 21:04
the ECONNREFUSED is because your child processes were not killed correctly, something else PM2 can help avoid. — dandavis, Oct 23 '15 at 21:05
@dandavis Does that work with SocketCluster in particular? It has its own clustering mechanism. — SomeKittens, Oct 23 '15 at 21:31
not sure about that specifically, but PM2 can handle things besides node, so "probably" if i had to guess... — dandavis, Oct 23 '15 at 21:44

score 2 · Accepted Answer · answered Oct 23 '15 at 21:02

nodemon sends the SIGUSR2 signal to the main (Master) process. SocketCluster (correctly) interprets this as as a request to reboot the workers. Unfortunately, there's an open issue where things are not shut down properly and errors fly all around.

There are two options:

You can add the code from the linked issue:

house.addShutdownHandler(function(ctx, next){
    socketCluster.killWorkers();
    socketCluster.killBrokers();
    next();
});

or use forever to send a "restart everything" signal:

forever -w --killSignal=SIGTERM server.js

Hi .. where exactly would one implement this? is this a patch i'd need to specify in the sc code itself? I'm confused over the `house` variable used — Jayaram, Aug 24 '16 at 06:19

score 0 · Answer 2 · answered Nov 16 '16 at 16:38

0

Improvements were made for nodemon in SC version 5.0.23 or later.

Make sure that you pass killMasterOnSignal: true when instantiating SocketCluster in your code (server.js file) - This setting is necessary for nodemon to work.

answered Nov 16 '16 at 16:38

Jon

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How do I get SocketCluster to restart on file change?

2 Answers2