Question

I have a node.js script on my server that I want to run continuously even after I logout of SSH. I decided to use forever for this.

Problem: When I try to start the node.js script using forever start app.js, I get the following error. Is there more configuration that is required?

The "sys" module is now called "util". It should have a similar interface.
info:   Forever processing file: app.js
{
  "process": {
    "pid": 24257,
    "uid": 0,
    "gid": 0,
    "cwd": "/home/node/nodejs",
    "execPath": "/usr/local/bin/node",
    "version": "v0.6.2",
    "argv": [
      "node",
      "/usr/local/bin/forever",
      "start",
      "app.js"
    ],
    "memoryUsage": {
      "rss": 13729792,
      "heapTotal": 8367232,
      "heapUsed": 5130572
    }
  },
  "os": {
    "loadavg": [
      0.02734375,
      0.0322265625,
      0.0009765625
    ],
    "uptime": 1474229.393550878
  },
  "trace": [
    {
      "column": 21,
      "file": "/usr/local/lib/node_modules/forever/lib/forever/cli.js",
      "function": "getOptions",
      "line": 172,
      "method": null,
      "native": false
    },
    {
      "column": 17,
      "file": "/usr/local/lib/node_modules/forever/lib/forever/cli.js",
      "function": "",
      "line": 210,
      "method": null,
      "native": false
    },
    {
      "column": 19,
      "file": "/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js",
      "function": "apply",
      "line": 355,
      "method": null,
      "native": false
    },
    {
      "column": 9,
      "file": "/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js",
      "function": "_every",
      "line": 28,
      "method": null,
      "native": false
    },
    {
      "column": 16,
      "file": "/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js",
      "function": "apply",
      "line": 352,
      "method": null,
      "native": false
    },
    {
      "column": 9,
      "file": "/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js",
      "function": "_every",
      "line": 28,
      "method": null,
      "native": false
    },
    {
      "column": 5,
      "file": "Object].invoke (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js",
      "function": "[object",
      "line": 350,
      "method": null,
      "native": false
    },
    {
      "column": 8,
      "file": "Object].dispatch (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/cli.js",
      "function": "[object",
      "line": 67,
      "method": null,
      "native": false
    },
    {
      "column": 21,
      "file": "Object].start (/usr/local/lib/node_modules/forever/node_modules/flatiron/lib/flatiron/plugins/cli.js",
      "function": "[object",
      "line": 52,
      "method": null,
      "native": false
    },
    {
      "column": 9,
      "file": "/usr/local/lib/node_modules/forever/lib/forever/cli.js",
      "function": null,
      "line": 470,
      "method": null,
      "native": false
    }
  ],
  "stack": [
    "TypeError: Cannot call method 'reset' of undefined",
    "    at getOptions (/usr/local/lib/node_modules/forever/lib/forever/cli.js:172:21)",
    "    at Object.<anonymous> (/usr/local/lib/node_modules/forever/lib/forever/cli.js:210:17)",
    "    at apply (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js:355:19)",
    "    at _every (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js:28:9)",
    "    at apply (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js:352:16)",
    "    at _every (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js:28:9)",
    "    at [object Object].invoke (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/router.js:350:5)",
    "    at [object Object].dispatch (/usr/local/lib/node_modules/forever/node_modules/flatiron/node_modules/director/lib/director/cli.js:67:8)",
    "    at [object Object].start (/usr/local/lib/node_modules/forever/node_modules/flatiron/lib/flatiron/plugins/cli.js:52:21)",
    "    at /usr/local/lib/node_modules/forever/lib/forever/cli.js:470:9"
  ],
  "level": "error",
  "message": "uncaughtException"
}

Additional Info

When installing forever using npm install forever -g, I get the following warnings, wonder if its relevant to the problem…

npm WARN eventemitter2@0.4.1 package.json: 'contributers' should probably be 'contributors'
npm WARN request@2.1.1 package.json: bugs['web'] should probably be bugs['url']

Answer 1

To run process at the back end

$ nohup node simple-server.js > output.log &

The purpose of Forever is to keep a child process (such as your node.js web server) running continuously and automatically restart it when it exits unexpectedly. It’s worth mentioning that there are other tools written to accomplish this task in a more generic way for any program or programming language:

Monit: http://mmonit.com/monit/
Upstart: http://upstart.ubuntu.com/
Daemontools: http://cr.yp.to/daemontools.html
Launchtool: http://people.debian.org/~enrico/launchtool.html