EADDRINUSE in Azure

[sbiaudet]

I use nodejs for my websites in azure website. When I made a stress test I've a EADDRINUSE error to external rest api call (azure table, ....) and the server crash.

I've made no special changes in iisnode config, just errors et logs enabled.

What can I do ?

[markusahlstrand]

Hi sbiaudet,

We had and have similar issues so any tips on how to resolve it properly would be much appreciated.

We started to look at this blog post on the topic: http://blog.gluwer.com/2014/03/story-of-eaddrinuse-and-econnreset-errors/

So far we set the maxsocket to 1000 (http.globalAgent.maxSockets = 1000) and lowered the timeout for any external calls to 55 seconds. Still have a few EASSEINUSE error's but it improved quite a bit.

[sbiaudet]

Hi @markusahlstrand ,

changing the globalAgent is not enough, if you use default httpModule. You can use forever-agent https://github.com/mikeal/forever-agent. It manage a connection pool to avoid this problem.

We have this problem specificly with azure storage - https://github.com/Azure/azure-storage-node. Azure storage default implementation use httpModule. We've made a fork to use forever agent instead of httpModule https://github.com/Azure/azure-storage-node/issues/11.

[markusahlstrand]

Hi @sbiaudet

There's support for custom agents in the latest release now. We use the keep-alive-agent and it works just fine.

[murdockcrc]

@markusahlstrand can you post some code on how to use custom agents? I am using the azure storage npm package to make many requests to azure tables, which fail with EADDRINUSE errors when fully loaded.

[sbiaudet]

@murdockcrc you can found below an example to use custom agent with agentkeepalive https://github.com/node-modules/agentkeepalive

var http = require('http');
var https = require('https');
var Agent = require('agentkeepalive');
var HttpsAgent = require('agentkeepalive').HttpsAgent;
....
http.globalAgent = new Agent();
https.globalAgent = new HttpsAgent();

[murdockcrc]

@sbiaudet I can confirm, running the app on node 0.12.0 AND adding the agentkeepalive as described above caused a BIG BIG BIG improvement time on my scale tests againt Azure. Thanks for the pointer.