Nodejs Mongoose 'Operation `XXX.find()` buffering timed out after 10000ms' - node.js

Question

index.ts is the entry point of this NodeJS program.
This is the code in index.ts:
import JobWorker from "./worker";
import { SwitchPlan } from "./jobs";
const worker = new JobWorker();
worker.addJob(SwitchPlan);
This is worker.ts:
import { CronJob } from "cron";
import mongoose from "mongoose";
import Config from "./config";
import logger from "./logger";
export default class JobWorker {
private jobs: CronJob[];
private config: {
NAME: string;
MONGO_URL: string;
};
constructor() {
this.config = Config;
this.connectDB();
this.jobs = [];
}
public async connectDB(): Promise<void> {
try {
await mongoose.connect(this.config.MONGO_URL,
{ useUnifiedTopology: true, useNewUrlParser: true, useCreateIndex: true },
);
logger.info("\nMONGODB has been connected\n");
} catch(err) {
logger.error("ERROR occurred while connecting to the database");
}
}
addJob(cronJob: CronJob) {
this.jobs.push(cronJob);
}
}
This is jobs.ts:
import moment from "moment";
import {
DatabaseOperations, Vehicle,
Plan1Doc, Plan1, VehicleDoc
} from "common-lib";
import logger from "../logger";
import { CronJob } from "cron";
const vehicleOps = new DatabaseOperations(Vehicle);
const SwitchPlan = new CronJob("25 * * * * *", async (): Promise<void> => {
const date: Date = moment(new Date()).startOf("date").toDate();
const expiringVehicles: VehicleDoc[] = vehicleOps.getAllDocuments(
{ "inspection.startTime": {
"$gte": date, "$lte": moment(date).startOf("date").add(1, "day").toDate()
}
},
{}, { pageNo: 0, limit: 0 }
).then((result: any) => {
logger.info("dsada");
}).catch((err: any) => {
logger.info("ssd");
});
});
SwitchPlan.start();
export { SwitchPlan };
I have omitted parts of code which are irrelevant to this problem. I ran this code through a debugger and there's no issue with the config. MonggoDB connected is getting printed at the start of the program. However the then block after getAllDocuments in jobs.ts is never reached and it always goes in the error block with the message, Operation vehicleinventories.find() buffering timed out after 10000ms. The getAllDocuments uses MongoDB's find() method and is working correctly because I am using this method in other projects where I have no such issues.
So far I have tried, deleting Mongoose from node_modules and reinstalling, tried connecting to MongoDB running on localhost, but the issue remains unsolved.
EDIT: DatabaseOperations class:
import { Model, Schema } from "mongoose";
class DatabaseOperations {
private dbModel: Model<any>;
constructor(dbModel: Model<any>) {
this.dbModel = dbModel;
}
getAllDocuments(
query: any,
projections: any,
options: { pageNo: number; limit: number },
sort?: any
): any {
const offset = options.limit * options.pageNo;
return this.dbModel
.find(query, projections)
.skip(offset)
.limit(options.limit)
.sort(sort ? sort : { createdAt: -1 })
.lean();
}
}

Answer 1

in your jobs.ts file you have the following line
SwitchToTier1Plan.start();
This line is called the moment you required the class file, hence before mongoose is connected, and all the models defined. Could this be the issue?
Another thing I noted is u are using mongoose.connect which may be wrong since mongoose.connect creates a global connection.
which means each new Worker you will be attempting to override the mongoose property with previous connection
Though i'm not sure what the implication is, but it could be because your .find could be using the old connection.
Since you are writing class, I would recommend using mongoose.createConnection which creates a new connection for each class initiation.