Error method sendAll() in nodejs using firebase-admin - node.js

Question

I use firebase-admin for nodejs(version 7.3.0) for sending push
notifications. For 40k distinct messages sending with method sendAll often server received this error:
"Credential implementation provided to initializeApp() via the "credential"
property failed to fetch a valid Google OAuth2 access token with the
following error: "Error fetching access token: Error while making request:
socket hang up. Error code: ECONNRESET".
Sometimes it works well but not all the time.
var admin = require('firebase-admin');
serviceAccount = require('/path_json_adminsdk/yyyyyyyyyy.json');
var defaultApp = admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
databaseURL: 'https://api-project-yyyyyy'
});
var k = 42000;
var contorMessages = 0;
var messages = [];
for(var i=0;i <em><</em> k; i++){
//.......
contorMessages = contorMessages + 1;
var tmp = {
alert: body.alert,
payload: body.payload
};
//form the array to be sent
messages.push({
data: {"body": JSON.stringify(tmp)},
token: body.token
});
if(contorMessages == 100){
SEDispatcher.emit('sendMessageFirebaseMulticast',messages);
contorMessages = 0;
messages = [];
}
}
SEDispatcher.on('sendMessageFirebaseMulticast', function(messages){
var dryRun = true;
admin.messaging().sendAll(messages, dryRun)
.then(function(response) {
//console.log("response:",response);
//responses = response.responses;
//.......
})
.catch((error) => {
console.log(' +++ Error sending message:', error);
});
});
the error that occurs sometimes:
+++ Error sending message: { Error: Credential implementation provided to initializeApp() via the "credential" property failed to fetch a
valid Google OAuth2 access token with the following error: "Error
fetching access token: Error while making request: socket hang up.
Error code: ECONNRESET".
at FirebaseAppError.Error (native)
at FirebaseAppError.FirebaseError [as constructor] (/opt/node/test/node_modules/firebase-admin/lib/utils/error.js:42:28)
at FirebaseAppError.PrefixedFirebaseError [as constructor] (/opt/node/test/node_modules/firebase-admin/lib/utils/error.js:88:28)
at new FirebaseAppError (/opt/node/test/node_modules/firebase-admin/lib/utils/error.js:122:28)
at /opt/node/test/node_modules/firebase-admin/lib/firebase-app.js:121:23
at process._tickCallback (internal/process/next_tick.js:103:7) errorInfo: { code: 'app/invalid-credential',
message: 'Credential implementation provided to initializeApp() via the "credential" property failed to fetch a valid Google OAuth2
access token with the following error: "Error fetching access token:
Error while making request: socket hang up. Error code: ECONNRESET".'
}, codePrefix: 'app' }

Answer 1

const messaging = getMessaging(defaultApp);
Need to be load

Answer 2

let serviceAccount = require('./google.json');
function messaging() {
const defaultApp = initializeApp({
credential: admin.credential.cert(serviceAccount)
});
const messaging = getMessaging(defaultApp);
const topic = 'highScores';
const message = [
{
data: {
score: '850',
time: '2:45'
},
topic: topic
}
];
messaging
.sendAll(message, true)
.then(function (response) {
console.log('response:', response);
})
.catch((error) => {
console.log(' +++ Error sending message:', error);
});
}
Assuming that the JSON is the file that contains your private key that is generated when registering the project