Error: listen EADDRINUSE

I’m deployed on Modulus and since Nov 2015 I’ve occasionally seen this error a few times a week, but in the last two days, the error rate has jumped to a peak of once every 10 seconds. I haven’t deployed any changes to my code in the last two days, so I’m not exactly sure what changed.

Here’s the error:

Error: listen EADDRINUSE
at errnoException (net.js:905:11)
at Server._listen2 (net.js:1043:14)
at listen (net.js:1065:10)
at net.js:1147:9
at dns.js:72:18
at process._tickCallback (node.js:448:13)

I contacted Modulus support and they asked if I touch any ports in my code. I don’t, so they thought it may have to do with Kadira. I’ve contacted @arunoda through Kadira support, but figured I’d ask here in case anyone has run into the same issue.

Here’s a gist of the full error stack.

Would appreciate any help or thoughts on how to resolve this. Thanks!