javascriptnode.jscronchild-processnode-cron

Cron job with child_process not ending child_process of previous run


I have this code:

let { exec } = require("child_process");
const job = new cron.schedule("*/2 * * * *", function () {
        console.log("Cron job Twitter API started");

        exec(
            "node /home/user/Raid/src/sub2/index.js",
            function (error, stdout, stderr) {
                if (error) {
                    console.log(error.stack);
                    console.log("Error code: " + error.code);
                    console.log("Signal received: " + error.signal);
                }
                console.log("Child Process STDOUT: " + stdout);
                console.log("Child Process STDERR: " + stderr);
            }
        );
    });

The problem is, that every 2 minutes the child process is started but not terminated. How can I properly terminate the child_process? The memory of my server is growing very fast and forcing a restart every hour.

I also tried this implementation but with this I did not got an error but the code did not work.

let { exec } = require("child_process");
const job = new cron.schedule("*/2 * * * *", function () {

                if(exec){
                   exec.kill(0);
                }
        console.log("Cron job Twitter API started");

        exec(
            "node /home/user/Raid/src/sub2/index.js",
            function (error, stdout, stderr) {
                if (error) {
                    console.log(error.stack);
                    console.log("Error code: " + error.code);
                    console.log("Signal received: " + error.signal);
                }
                console.log("Child Process STDOUT: " + stdout);
                console.log("Child Process STDERR: " + stderr);
            }
        );
    });

The problem is, that every 2 minutes the child process is started but not terminated. How can I properly terminate the child_process? The memory of my server is growing very fast and forcing a restart every hour.


Solution

  • exec() returns a child object, so you could do it like this:

    let childProcess = '0';
        const job = new cron.schedule("*/2 * * * *", function () {
            if (childProcess != '0') {
                childProcess.kill(0);
            }
            console.log("Cron job Twitter API started");
    
            childProcess = exec(
                "node /home/eliasxxx97/Raid/src/sub2/index.js",
                function (error, stdout, stderr) {
                    if (error) {
                        console.log(error.stack);
                        console.log("Error code: " + error.code);
                        console.log("Signal received: " + error.signal);
                    }
                    console.log("Child Process STDOUT: " + stdout);
                    console.log("Child Process STDERR: " + stderr);
                }
            );
        });