小编Wik*_*own的帖子

我正在Google App Engine灵活环境中运行firebase。我在一个节点上设置了一个添加子项的侦听器，每次添加一个子项时，它将被调用两次。仅当我在Google App Engine上运行此代码时，才会发生这种情况。如果我在本地运行，它将按预期运行。这是代码

// [START app]
'use strict';

var express = require('express');
var bodyParser = require('body-parser');
var request = require('request');
var firebase = require('firebase-admin');

var app = express();

firebase.initializeApp({
    credential: firebase.credential.applicationDefault(),
    databaseURL: "https://myurl.firebaseio.com/"
});

var db = firebase.database();
var globalNotifications = db.ref("/globalNotifications");

var API_KEY = "myKey"; // Your Firebase Cloud Server API key
var now = new Date();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

globalNotifications.orderByChild('processed').equalTo(0).on("child_added", function(snapshot) {

    var key = snapshot.key;
    var incomingNotification = snapshot.val();
    var userID = incomingNotification.userID; …