- 1 year ago
does Node kill spawned child processes automatically?
No, by default, Node.js does not automatically kill spawned child processes. When you spawn a child process in Node.js using the child_process
module, it creates a separate operating system process that is independent of the Node.js process.
It is your responsibility as the developer to manage the lifecycle of the spawned child processes and ensure that they are appropriately terminated when no longer needed. If you fail to do so, the child processes may continue running even after the Node.js parent process has terminated.
To properly handle the lifecycle of child processes, you can:
Use the
child_process
module'sspawn
orexec
methods, which return instances ofChildProcess
. These instances have akill()
method that you can use to terminate the child process explicitly when necessary.Listen for the
exit
event on the child process object and handle it accordingly. This event is emitted when the child process exits, either naturally or due to an error or termination signal. You can use this event to perform cleanup tasks or take appropriate actions when the child process has completed its execution.Here's an example of listening for the
exit
event and explicitly terminating the child process:javascriptconst { spawn } = require('child_process');
const childProcess = spawn('command');
childProcess.on('exit', (code, signal) => {
console.log(`Child process exited with code ${code} and signal ${signal}`);
// Perform cleanup or additional actions here
});
It's important to note that if the parent Node.js process is forcefully terminated, such as by a system shutdown or a SIGKILL
signal, the child processes may continue running. In such cases, you might need to implement additional handling to ensure proper termination of child processes.
Always make sure to manage the lifecycle of child processes appropriately to avoid resource leaks and unexpected behavior.