I am using MongoClient in NodeJs to carry out Db operations, I am running into connection and db caching issues,
I’m getting the following error in my application -
error 1 -
Error: Client network socket disconnected before secure TLS connection was established
at connResetException (internal/errors.js:609:14)
at TLSSocket.onConnectEnd (_tls_wrap.js:1557:19)
at Object.onceWrapper (events.js:420:28)
at TLSSocket.emit (events.js:326:22)
at TLSSocket.EventEmitter.emit (domain.js:483:12)
at endReadableNT (_stream_readable.js:1241:12)
at processTicksAndRejections (internal/process/task_queues.js:84:21) {
name: 'MongoNetworkError'
error 2-
MongoServerSelectionError: Server selection timed out after 30000 ms
at Timeout._onTimeout (/var/task/node_modules/mongodb/lib/core/sdam/topology.js:430:30)
at listOnTimeout (internal/timers.js:554:17)
at processTimers (internal/timers.js:497:7) {
reason: TopologyDescription {
type: 'ReplicaSetNoPrimary',
setName: 'atlas-3kud01-shard-0',
maxSetVersion: null,
maxElectionId: null,
servers: Map {
'productioneuro-shard-00-00.vfau2.mongodb.net:27017' => [ServerDescription],
'productioneuro-shard-00-01.vfau2.mongodb.net:27017' => [ServerDescription],
'productioneuro-shard-00-02.vfau2.mongodb.net:27017' => [ServerDescription]
},
stale: false,
compatible: true,
compatibilityError: null,
logicalSessionTimeoutMinutes: 30,
heartbeatFrequencyMS: 10000,
localThresholdMS: 15,
commonWireVersion: 9
}
}
Following is my DB connection and closing code-** I call the client method while going any db operation like findOne, insertOne, etc
And closeDBConnection right before returning the API response.
import { MongoClient, Db } from "mongodb";
let cachedDb: Db = null;
let mongoClient: MongoClient = null;
export const client = async (): Promise<Db> => {
if (cachedDb && await mongoClient.isConnected()) {
console.info("cached db connection established");
return cachedDb;
}
mongoClient = new MongoClient('db URL here', {
useUnifiedTopology: true,
useNewUrlParser: true,
connectTimeoutMS: 90000,
poolSize: 10
});
try {
await mongoClient.connect();
if (await !mongoClient.isConnected()) {
await mongoClient.connect(err => {
if (err) {
console.error("Error : ", err);
throw new Error(`Unable to connect MongoDb Client, Reason: ${err}`
);
}
});
}
cachedDb = await mongoClient.db(await "DB name here");
console.info("db connection established");
return cachedDb;
} catch (error) {
console.error("Error in connecting to DB => ", error);
throw error;
}
};
export const closeDBConnection = async () => {
try {
if( mongoClient != null ){
await mongoClient.close();
mongoClient = null;
cachedDb = null;
console.log("db connection closed");
return true;
}
} catch (error) {
console.log("Error in closeDBConnection => ", error);
return false;
}
};