I have an express server and i trying to schedule a job to send automatic emails at a particular time(10:00 am in my case). And i am using node-cron package to schedule jobs.
But i am making use of clustering technique to increase my app performance due to which there are multiple workers created and running constantly. In my implementation i am creating workers equal to total cpu of my machine because of which i have 8 workers running at all times.
To perform a job i have to schedule the job in my server.js, due to which my job i running 8 times at that particular time but i want it to run only once at that particular time.
Below is my server.js:
require("dotenv").config();
const express = require("express");
const { errorHandler } = require("./middleware/errorMiddleware");
const connectDB = require("./config/db");
const cors = require("cors");
const cluster = require("cluster");
const totalCPUs = require("os").cpus().length;
const process = require("process");
var cron = require('node-cron');
const port = process.env.PORT || 5000;
if (cluster.isMaster) {
// console.log(`Number of CPUs is ${totalCPUs}`);
// console.log(`Master ${process.pid} is running`);
// Fork workers.
for (let i = 0; i < totalCPUs; i++) {
cluster.fork();
}
// if any worker dies fork a new worker
cluster.on("exit", (worker, code, signal) => {
// console.log(`worker ${worker.process.pid} died`);
// console.log("Let's fork another worker!");
cluster.fork();
});
} else {
connectDB();
const app = express();
const corsOptions = {
origin: 'http://localhost:3000',
optionsSuccessStatus: 204
};
app.use(cors(corsOptions))
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use("/api/admin", require("./routes/adminRoutes"));
app.use(errorHandler);
// This job run at 10:00 am every day
cron.schedule('00 10 * * *', function() {
console.log('send email');
});
app.listen(port, () => {
console.log(`Running on ${port}`);
});
}
For this implementation i get send email 8 times in my console.
And if i take out that schedule out of if else block and keep that schedule at the very end of server.js like shown below then i get send email 9 times in my console
// same code as above
app.use(errorHandler);
app.listen(port, () => {
console.log(`Running on ${port}`);
});
}
// This job run at 10:00 am every day
cron.schedule('00 10 * * *', function() {
console.log('send email');
});
I tried few things but could not get the desired output. If there is any other way i can make use of then do tell me. Thanks in advance.
