opti-node

It's just node with some flags turned on or off to make it run better in resource restricted environments. You might want to do that in containers, low-budget projects, "embedded", or just to make development better.

Features that opti-node provides:

• ✓ Optimize for smaller memory rather than speed
• ✓ Expose gc() global function for manual garbage collection
• ✓ Efficient garbage collector settings with compaction
• ✓ Memory reducer
• 🐛 Hard abort process on errors and sloppy code
• ✓ Signal when idle
• ✓ Don't print anything unless it has to
• ✓ More helpful error messages
  • Maybe try to remove internal node modules from stack trace

Sometimes you'll get it down to 10 MB while node usually runs at over 40 MB. It keeps going back down to the minimum over time.

Note Sat Nov 17 2018: I tried launching the script with Bash and Zsh. Bash was lighter in memory so I put that into the opti-node shell script which launches node.

Note Wed Aug 7 2019: At some point they changed the flags from using underscores to dashes. If your node version uses underscores use opti-node@0.3.1. Otherwise all the new versions use the newer flags. Check node --v8-options if you are unsure.

systemd script

[Unit]
Description=my node script
After=network.target

[Service]
Type=simple
ExecStart=/path/to/app/node_modules/.bin/opti-node src/index.js
User=MY-NODE-USER
Restart=always
RestartSec=5
WorkingDirectory=/path/to/app
Environment=NODE_ENV=production

[Install]
WantedBy=multi-user.target

GNU-Linux info

If you run opti-node here's how you find it running:

ps -A | grep node
# 16387 ?        00:00:00 opti-node
# 16392 ?        00:00:01 node

ps 16387
#   PID TTY      STAT   TIME COMMAND
# 16387 ?        Ss     0:00 /bin/bash /path/to/app/node_modules/.bin/opti-node src/index.js

ps 16392
#   PID TTY      STAT   TIME COMMAND
# 16392 ?        Sl     0:01 node --optimize-for-size --expose-gc --gc-global --gc-interval=12000 --alw

ps 16392 | less
#   PID TTY      STAT   TIME COMMAND
# 16392 ?        Sl     0:01 node --optimize-for-size --expose-gc --gc-global --gc-interval=12000 --always-compact --memory-reducer --hard-abort --abort-on-uncaught-exception --abort-on-stack-or-string-length-overflow --use-idle-notification --max-stack-trace-source-length=1000 --no-deprecation --no-warnings --no-log-colour src/index.js

Your process numbers will different.

Maybe some other things will help:

• top -p 1234 -- the pid
• htop -p 1234 -- the pid

Windows

The script uses Bash. Unless Windows has a way to emulate or get around that I'm not sure yet how to add compatibility.

Is there a way to run cmd.exe or PowerShell IF on Windows?

Ideas?

If you have ideas how to slim down the node requirements and still have it work well across platforms let me know!

Install

npm install opti-node

Or globally

npm install--global opti-node

CLI use

opti-node dist/index.js

# debugging
opti-node debug dist/index.js
opti-node inspect dist/index.js

# repl
opti-node

# any extra node flags are fine
opti-node --require @babel/register \
  --experimental-modules \
  --trace-warnings \
  --pending-deprecation \
  dist/index.js

In package.json script

npm install opti-node

{
  "name": "my-module",
  "version": "0.0.1",
  "description": "my module with opti-node",
  "private": true,
  "dependencies": {
    "opti-node": "0.1.0"
  },
  "scripts": {
    "start": "opti-node dist/index.js"
  }
}

JavaScript use

require("opti-node").createProcess returns node ChildProcess

https://nodejs.org/dist/latest/docs/api/child_process.html#child_process_child_process_spawn_command_args_options

• cmd, string, optional, defaults to node
• args, string[] your node args added after opti-node's
• opts: object, customize node spawn options

const {createProcess} = require("opti-node")

// create the opti-node process and spawn a script
const proc = createProcess({args: ["dist/index.js"]})

//
proc.stdout.on("data", buf => {
  console.log("buf", buf)
  proc.kill()
})

proc.on("close", (code, signal) => {
  console.log("code", code)
  console.log("signal", signal)
})

proc.stdin.write(simpleMessage)

Limit memory to specific size

Try to constrain node memory size.

OPTI_NODE_LIMIT_RAM_MB=200 opti-node dist/index.js

Is this scientifically proven to be optimized?

No. Not yet. We might be able to prove it by enumerating node --v8-options then running tests on each of the flags. Ideally we can produce graphs that compare each flags across some tests.

Development

# create a dev build
npm run dev

# before commit run a full test
npm run prd

Science 🤓

We'll try to run tests as we learn. It should produce results if we are to use it.

• Studies

Copying, license, and contributing

Copyright (C) Tony Crowe github@tonycrowe.com (https://tcrowe.github.io) 2018

Thank you for using and contributing to make opti-node better.

⚠️ Please run npm run prd before submitting a patch.

⚖️ opti-node is Free Software protected by the GPL 3.0 license. See ./COPYING for more information. (free as in freedom)