Simple Process Manager

Simple Node.js process manager.

$ npm i simple-process-manager

Usage

If you want to start 3 instances of a background process:

$ pm start ./workers/background-command.js --total 3

The process manager will ensure that the process stays alive.

The worker has to expose a start and a stop functions.

module.exports = {
    start(config) {
        //initialize your worker...
    },
    close() {
        return new Promise(resolve => {
            //clean up code...
        });
    }
};

$ pm info
name:        example
worker:      /Users/peperone/simple-process-manager/server
instances:   8
description: Example showing how to run CLI process manager
pid:         19365
pids: 
  - 19366
  - 19367
  - 19368
  - 19369
  - 19370
  - 19371
  - 19372
  - 19373

$ pm restart background-command

Signals

SIGUSR2

If you want to restart your workers- say because you changed the script source code- you can use a signal using the leader's pid:

$ kill -SIGUSR2 <pid>

SIGTERM

This will terminate all workers immediately without waiting for them to clean up.

$ kill -SIGTERM <pid>

SIGINT

This will terminate all workers but will wait for them to clean up up to timeout.

$ kill -SIGINT <pid>

Changelog

• 2019-09-01 v0.4.2 Bug fixes
• 2019-09-01 v0.4.0 Added CLI commands to manage metadata and restart workers
• 2019-08-31 v0.3.0 Enable restarting workers using SIGUSR2 signal
• 2019-08-04 v0.2.0 Clean up, promisify, and expose CLI
• 2019-08-03 v0.1.0 Initial release

TODO

• [ ] Expose as a core.io-cli command plugin
• [ ] Create CLI so we can:
  • [x] list current workers
  • [x] restart workers
  • [ ] remove workers
• [ ] Pass metadata file location as option
• [ ] Memory graph: Show CLI UI with memory graph per worker
• [ ] Enable passing env to worker
• [ ] Abstract transport so we can communicate with workers using:
  • [ ] IPC
  • [ ] Unix socket
  • [ ] TCP socket
  • [ ] MQTT
• [x] Give each cluster leader a unique ID/name
• [ ] Provide interface so cluster leaders are addressable
  • [ ] Locally
  • [ ] Remotely
• [ ] Create a worker shell so we can wrap scripts that do not expose start/close.
• [ ] Enable loading custom configurations to pass along to workers

License

® 2019 License MIT by goliatone