I'm developing a web app using express, and MySQL. I was able to publish the app on heroku for testing. The problem came after few minutes or seconds, the server throws the following error:
Error: Connection lost: The server closed the connection.
at Protocol.end (/app/node_modules/mysql/lib/protocol/Protocol.js:112:13)
at Socket.<anonymous> (/app/node_modules/mysql/lib/Connection.js:94:28)
at Socket.<anonymous> (/app/node_modules/mysql/lib/Connection.js:526:10)
at Socket.emit (events.js:327:22)
When I restart the server, I'm able to execute some successful calls to database, but after some minutes, the connection get lost.
This is the connection file I'm currently using, I will, change my credentials for placeholders, only for security purppose.
module.exports = {
HOST: 'mysql5044hostname',
USER: 'myUserName',//root
PASSWORD: 'thisIsMyPassword',
DB: 'default_schema'
};
Any help regarding this matter, will be appreciated.
#vodolaz095 and #riscarrott thanks to both of you, I changed the logic based on the documentation you sent, and I was able to successfully connect to database without losing the communication with the server.
Related
I have created a server using net module:
// Creating and connecting with server
const net = require('net');
const server = net.createServer(); //Creating server
//Connecting with server
server.on('connection', function (socket) {
let remoteAddress = `${socket.remoteAddress},${socket.remotePort}`
console.log(remoteAddress)
console.log(`connection is established... ${Date.now()} \n `);
socket.write(`connection is established...${Date.now()} \n`);
//Receiving and Sending payload from/to client
socket.on('data', async function (payload) {
console.log("payload from client",payload)
socket.write(`acknowledge : ${payload}`);
});
//Close connection
socket.on('close', function () {
console.log('Server Connection Closed');
});
//Server error
socket.on('error', function (err) {
console.log("Caught flash policy server socket error: ")
console.log(err.stack)
});
});
server.listen(8001, function () {
console.log('Server Listing on Port 8001');
})
I deploy this code to AWS EC2 and When I tried to connect with telnet client (telnet ec2_ip 8001), initailly it is working but after sometime it is giving following errors.
screenshot of telnet client:
screenshot of ec2 logs:
And When I tried to connect with real IOT scooter with ec2 Ip address and port 8001, It is not connecting for even a second.
Can anyone please tell me what I am doing wrong?
Note: I don't have much knowledge about IoT. This is the first time I am connecting an IoT scooter with nodejs.
It is hard to know exactly what your problem is without seeing more of your code, or getting more explained. Like what happens in your real code? The logs seem to indicate that you are making outbound calls to another service after the initial connection. If that is the case, are you handling error conditions of your dependencies correctly? An unhandled exception would kill your server, and it would need to be restarted to work again. If you are using dependencies that fail, for instance databases, other servers, configuration files etc that fail on your scooter, that may be why it fails without even allowing one single connection. But without knowing more specifics about your application and architecture, it is just wild guesses at this point.
Your server example code, seems fine. As long as you have opened for traffic on that port in your routing configuration in AWS, it should respond. It could be that you just simply run out of connections, but again that requires me to know more to give you a definitive answer.
My advice would be to check your dependencies, and your logs for supporting systems.
I am trying to connect to my MS SQL database via node.js (Express), but the connection cannot be established. I have probably wrong configuration, but I have tried everything and nothing worked. I also enabled TCP/IP in configuration Manager.
Here is my JS code: https://snipboard.io/ufk49d.jpg
Here is one of my errors: https://snipboard.io/wyTbLi.jpg
When I add localhost or IP adress before SQLEXPRESS in server configuration, it thow this error: https://snipboard.io/RE6Xov.jpg
And also, I added new user and allow SQL auth and windows auth connection.
Thanks for your tips!
Can you put your machine name in server parameter?
server: 'YOUR_MACHINE_NAME\\SQLEXPRESS',
I have a node app connecting to a redis cache hosted on azure but whenever I'm trying to connect to it, the connection fails with an error message
I have enabled secure connection through a port and configured my node app accordingly
// This is my client module
const Redis = require("ioredis");
var client = new Redis(
{
port: 6380,
tls: true,
host: process.env.REDIS_HOST,
password: process.env.REDIS_PASSWORD,
family:
db: 0
}
);
module.exports = client;
This is the error I encounter whenever I start my app:
[ioredis] Unhandled error event: Error: unable to get local issuer certificate
at TLSSocket.onConnectSecure (_tls_wrap.js:1317:34)
at TLSSocket.emit (events.js:209:13)
at TLSSocket._finishInit (_tls_wrap.js:792:8)
at TLSWrap.ssl.onhandshakedone (_tls_wrap.js:606:12)
The API ran for a while without any problems but then started throwing this error. My colleague is not having a problem running the same service and I'm assuming this is my machines certificates or lack of causing the issue. Any solutions or suggestions?
The problem was with the company wifi network I was using. The firewall did not allow me to connect to the cache.
I am trying to use Paho's JavaScript library to connect to a Mosquito MQTT server. I have just used the example on the Paho website. Which is:
function onConnect() {
console.log("onConnect");
client.subscribe("harleyRowland/myTopic");
message = new Paho.MQTT.Message("Hello");
message.destinationName = "harleyRowland/myTopic";
client.send(message);
}
onConnect();
On Safari, I get the following error:
Error: AMQJS0011E Invalid state not connected.
and on Chrome, I get the following error as well as the one above:
WebSocket connection to 'ws://mosquitoServer.co.uk:1883/mqtt' failed:
Error during WebSocket handshake: net::ERR_CONNECTION_RESET
I need to use the Mosquito server for this work. Is it possible using JavaScript? If it isn't possible, is there another web technology I could use?
You need to add a websockets listener to your mosquitto setup. you do this by adding something like the following to your mosquitto.conf
listener 1884
protocol websockets
This will listen for MQTT over websockets on port 1884 (not 1883 as you can not run both on the same socket with mosquitto).
You will also need to be running mosquitto newer than 1.4 and not on Windows unless you compile it yourself
I'm trying to connect the Mongo shell with Mongolab. I am using my mongolab username and password but it is giving an error: "Failed to connect to 54.81.180.188:56789."
My userName and password is correct.
I'm using Windows 8.1
When I ping ds0-----.mongolab.com that's working fine.
C:\mongodb\bin>mongo ds0----.mongolab.com:56789/dbname -u "MyUserName" -p "MyPassword"
MongoDB shell version: 3.0.3
connecting to: ds027751.mongolab.com:56789/dbname
2015-06-05T10:55:30.019+0530 W NETWORK Failed to connect to 54.81.180.188:56789, reason: errno:10061 No connection could be made because the target machine actively refused it.
2015-06-05T10:55:30.024+0530 E QUERY Error: couldn't connect to server ds027751.mongolab.com:56789 (54.81.180.188), connection attempt failed
at connect (src/mongo/shell/mongo.js:181:14)
at (connect):1:6 at src/mongo/shell/mongo.js:181
exception: connect failed
I had the same problem, my server abruptly lost the ability to connect to MongoLab. I contacted support, who sent this reply:
Hello,
Your Experimental Sandbox plan is running MongoDB 3.0.x, which
includes changes to Mongo's authentication mechanism. This new
mechanism is supported by certain newer driver versions, as described
at
http://docs.mongodb.org/manual/release-notes/3.0-scram/#upgrade-drivers.
To connect to this database, you will need to use one of the drivers
listed at the above link.
Please let us know if you have questions about this.
Sincerely, Samson
I assume I was upgraded automatically, as I hadn't touched the server code or MongoLab in months. As an immediate fix, I just created a new db in MongoLab, which was created in mongod v2.6.9 (I don't remember seeing an option to choose the version).