Stackhero for Memcached

This add-on is operated by Stackhero

Memcached on dedicated instances, up-to-date versions and attractive prices

Stackhero for Memcached

Last updated April 20, 2023

The Stackhero for Memcached add-on is currently in beta.

The Stackhero for Memcached add-on provides a managed Memcached running on a fully dedicated instance. It provides the following features:

  • A private instance (dedicated VM)
  • A dedicated public IP (v4)
  • TLS encryption (aka SSL)
  • An automatic backup every 24 hours
  • One click to update to new Memcached versions

Provisioning the Add-on

Stackhero for Memcached can be attached to a Heroku application via the CLI:

A list of all plans available can be found here.

$ heroku addons:create ah-memcached-stackhero --app <your app name>
-----> Adding ah-memcached-stackhero to sharp-mountain-4005... done

After you provision Stackhero for Memcached, multiple config variables are available in your app’s configuration:

  • STACKHERO_MEMCACHED_HOST
  • STACKHERO_MEMCACHED_PORT_TLS
  • STACKHERO_MEMCACHED_PORT_CLEAR
  • STACKHERO_MEMCACHED_USER
  • STACKHERO_MEMCACHED_PASSWORD

You can see the content of these variables via the heroku config:get command:

$ heroku config:get STACKHERO_MEMCACHED_HOST
$ heroku config:get STACKHERO_MEMCACHED_PORT_TLS
$ heroku config:get STACKHERO_MEMCACHED_PORT_CLEAR
$ heroku config:get STACKHERO_MEMCACHED_USER
$ heroku config:get STACKHERO_MEMCACHED_PASSWORD

Local Setup

After you provision the add-on, you must replicate its config variables locally.

Use the Heroku Local command-line tool to configure, run, and manage process types specified in your app’s Procfile. Heroku Local reads configuration variables from an .env file. To view all of your app’s config variables, type heroku config. Use the following command for each value you want to add to your .env file:

heroku config:get <STACKHERO_MEMCACHED_VARIABLE> -s  >> .env

For example:

$ heroku config:get STACKHERO_MEMCACHED_HOST >> .env
$ heroku config:get STACKHERO_MEMCACHED_PORT_TLS >> .env
$ heroku config:get STACKHERO_MEMCACHED_PORT_CLEAR >> .env
$ heroku config:get STACKHERO_MEMCACHED_USER >> .env
$ heroku config:get STACKHERO_MEMCACHED_PASSWORD >> .env

Don’t commit credentials and other sensitive configuration values to source-control. In Git, exclude the .env file with: echo .env >> .gitignore.

For more information, see Heroku Local.

Connect to the Stackhero Dashboard

Stackhero dashboard allows you to see your instance usage, restart it, and apply updates. You can access the dashboard via the CLI:

$ heroku addons:open ah-memcached-stackhero
Opening ah-memcached-stackhero for sharp-mountain-4005

You can also visit the Heroku Dashboard, select your application, and then select Stackhero for Memcached from the Add-ons menu.

Connecting to Memcached

We recommend you use TLS encryption when connecting to Memcached. Use the following environment variables to connect:

  • STACKHERO_MEMCACHED_HOST
  • STACKHERO_MEMCACHED_PORT_TLS
  • STACKHERO_MEMCACHED_PORT_CLEAR
  • STACKHERO_MEMCACHED_USER
  • STACKHERO_MEMCACHED_PASSWORD

Configure Memcached on Ruby

First, install the “dalli” and “openssl” gem:

$ bundle add dalli openssl

Then, edit the config/environments/production.rb file and add this code:

require "openssl"
ssl_context = OpenSSL::SSL::SSLContext.new
ssl_context.verify_hostname = true
ssl_context.verify_mode = OpenSSL::SSL::VERIFY_PEER
ssl_context.ca_path = "/etc/ssl/certs"

config.cache_store = :mem_cache_store,
                    ENV["STACKHERO_MEMCACHED_HOST"] + ":11212",
                    {
                      :username => ENV["STACKHERO_MEMCACHED_USER"],
                      :password => ENV["STACKHERO_MEMCACHED_PASSWORD"],
                      :ssl_context => ssl_context
                    }

For more informations about configuring Memcached as a cache system for Ruby on Rails, you can consult the official Rails documentation here.

By default caching is only enabled on production environment.

If you need to test caching on development, edit the file config/environments/development.rb, add the configuration from above and add config.action_controller.perform_caching = true to enable caching.

A good way to test that caching works is to start a Rails console (with bin/rails console) and test writing with Rails.cache.write("foo", "bar").

Upgrading your Plan

You can’t downgrade an existing add-on.

Use the heroku addons:upgrade command to migrate to a new plan.

$ heroku addons:upgrade ah-memcached-stackhero:newplan
-----> Upgrading ah-memcached-stackhero:newplan to sharp-mountain-4005... done
       Your plan has been updated to: ah-memcached-stackhero:newplan

Manage migration timing to ensure your application is available during the migration process.

Removing the Add-on

You can remove Stackhero for Memcached via the CLI:

This will destroy all associated data and can’t be undone!

$ heroku addons:destroy ah-memcached-stackhero
-----> Removing ah-memcached-stackhero from sharp-mountain-4005... done

Support

Stackhero for Memcached support and runtime issues should be submitted via one of the Heroku Support channels. We recommend adding support@stackhero.io in copy for urgent issues.

Additional Resources

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