buildpack-mimalloc

mimalloc is a general purpose malloc implementation. This buildpack makes it easy to install and use mimalloc on Heroku and compatible platforms.

Install

heroku buildpacks:add --index 1 https://github.com/gaffneyc/buildpack-mimalloc.git
git push heroku master

Made possible by Dead Man's Snitch

Continued development and support of the mimalloc buildpack is sponsored by Dead Man's Snitch.

Ever been surprised that a critical recurring job was silently failing to run? Whether it's backups, cache clearing, sending invoices, or whatever your application depends on, Dead Man's Snitch makes it easy to monitor heroku scheduler tasks or to add cron job monitoring to your other services.

Get started for free today with Dead Man's Snitch on Heroku

Usage

Recommended

Set the MIMALLOC_ENABLED config option to true and mimalloc will be used for all commands run inside of your dynos.

heroku config:set MIMALLOC_ENABLED=true

Per dyno

To control when mimalloc is configured on a per dyno basis use mimalloc.sh <cmd> and ensure that MIMALLOC_ENABLED is unset.

Example Procfile:

web: mimalloc.sh bundle exec puma -C config/puma.rb

Configuration

MIMALLOC_ENABLED

Set this to true to automatically enable mimalloc.

heroku config:set MIMALLOC_ENABLED=true

To disable mimalloc set the option to false. This will cause the application to restart disabling mimalloc.

heroku config:set MIMALLOC_ENABLED=false

MIMALLOC_VERSION

Set this to select or pin to a specific version of mimalloc. The default is to use the latest stable version if this is not set. You will receive an error mentioning tar if the version does not exist.

Default: 2.2.4

note: This setting is only used during slug compilation. Changing it will require a code change to be deployed in order to take affect.

heroku config:set MIMALLOC_VERSION=2.2.4

Likely Questions

How do I know it's working?

heroku run -a [app name] -- bash -c 'MIMALLOC_SHOW_STATS=1 ruby -e exit'

When mimalloc is configured correctly that will print out a table of stats. As long as you see output you can be sure that mimalloc is at least loaded correctly.

Development

Run make console to start up a shell in a test build environment that mimic's Heroku's build phase.