Node.js process.domain is undefined sometimes

Question

In Node.js project build with LoopbackJS I need to store data during request. So I used domain feature: ``` // pre-processing middleware app.use(function (req, res, next) { // create per request domain instance var domain = require('domain').create(); // save request and response to domain, to make it accessible everywhere domain.req = req; domain.res = res; domain.run(next); }); ``` Later in required module: ``` Model.beforeRemote('**', function(oContext, oModel, next) { // Save method name for later use process.domain.remoteContext = { /* Here is an error thrown */ methodName: oContext.method.name }; ... process.domain.res.send() // example of usage }) ``` BUT when I make request from Safari or IE, process.domain is sometimes undefined! Requesting from Chrome or Firefox works as expected. Any suggestions? Error response: ``` {"error":{"name":"TypeError","status":500,"message":"Cannot set property 'remoteContext' of undefined","stack":"TypeError: Cannot set property 'remoteContext' o…

Accepted Answer

Just found out, that explisity binding req and res to domain at creation moment, solves undefined domains down in execution stack.

```
app.use(function (req, res, next) {
  // create per request domain instance
  domain.create().run(function() {
    // explicit binding
    process.domain.add(req)
    process.domain.add(res)
    // save request to domain, to make it accessible everywhere
    process.domain.req = req;
    process.domain.res = res;
    next()
  });
});
```

Don't know why this happens, so I leave question open for other possible advices.

Node.js process.domain is undefined sometimes

Solution

Problem