Ionic 2 Http.post hangs nodeJS express server

Question

I have a CouchDB database, and a nodeJS with express to make an API using couchdb-promises library.

In ionic 2 provider I do:

login(credentials) {
  let params = {
    username: credentials.email.toLowerCase(),
    password: SHA3(credentials.password).toString()
  };

  return new Promise((resolve, reject) => {
    this.http.post(API + '/auth/login', params)
      .map(res => res.json())
      .subscribe(data => {
          localStorage.setItem('user', JSON.stringify(data.user));
          resolve(true);
        });
      },
      error => {
        reject(Error(error._body));
      });
  });
}

It works fine the first time , but if I logout and try again, request hangs server and does not work. I need to restart server app in order to login again.

If I request via curl, I can post as many times as I want, but if I first login in Ionic 2 app, and then I send a curl request, I have not response either.

I first thougth it is problem in server side (and I tried other versions of nodejs), but only happens if I do the Ionic Http.post. Other request also hangs server, not only login. Seems only can be done one request at all.

What could be happening? Should I finalize the requests in any way?

Cordova CLI: 6.3.1 
Ionic CLI Version: 2.2.1
Ionic App Lib Version: 2.2.0
OS: Linux 4.4
Node Version: v7.8.0
express: 4.15.2
couchdb-promises: 3.0.0

Answer 1

The problem is not Ionic 2 itself, using in server nano instead of couchdb-promises works fine.

Still having no idea why couchdb-promises hangs with Ionic and does not with normal request.