Migrating from Heroku to Cloud 66

Overview

You can migrate your application from Heroku to Cloud 66 in 3 steps:

  1. Build and deploy your application’s code via the Cloud 66 dashboard
  2. Import your data to your new environment
  3. Redirect traffic to the new endpoint

Cloud 66 does not host applications. We automate the build and deployment of your application to the cloud provider of your choice, or your own servers (virtual or physical).

What you’ll need

Before you begin migrating your application please check you have the following:

An account with your cloud provider of choice. Cloud 66 supports AWS, Google Cloud, Azure, Linode, DigitalOcean, Packet, Rackspace and Cloud A.

What server size do I need?

Using Heroku, you can choose between 1X (512 MB), 2X (1 GB) and PX (6 GB) server sizes. This makes it easy to calculate your server requirements, and we recommend that you use similar server resources when deploying your application via Cloud 66. We also recommend that you have a separate server for your database in production environments.

Migrating

1. Build and deploy your code

Using the Cloud 66 Dashboard, you can pull your code directly from your Git repository and build it into a new version of your application on your own servers.

If you need help getting started, please read our Deploying your first Rails app guide.

We also have a guide to accessing your Git repository.

2. Data

Once your code is deployed, you’ll need to migrate your data across. The process differs for PostgreSQL and MySQL databases:

PostgreSQL

From your Heroku toolbelt, create a database backup URL by running heroku pgbackups:url. Next, visit your Application Overview and click the Import Heroku data link. Paste the URL provided by the toolbelt into the field, and click Import Heroku data.

MySQL

Start by dumping your existing database. Refer to the ClearDB documentation for common problems.

$ mysqldump -u [username] -p[password] [dbname] > backup.sql 

Once you have a MySQL dump file, use the Cloud 66 toolbelt to upload the file to your application database server. Remember to replace the fields below with your values.

$ cx upload -s "[app_name]" --server [database_server_name] backup.sql /tmp/backup.sql

Next, use the toolbelt to SSH to your server.

$ cx ssh -s "[app_name]" [server_first_name]

Finally, use the command below to import your backup into the database. You can find the generated username, password and database name by visiting your Application Overview and clicking into your database server (e.g. MySQL server).

$ mysql -u [generated_user_name] -p [generated_password] "[database_name]" < /tmp/backupfile.sql 

3. Traffic

Once you’re ready to serve traffic from your Cloud 66 application, you need to direct your traffic to it. For help doing this, see Configure your DNS.

Useful pointers

Web server and Procfile

By default, Cloud 66 will deploy your application with Phusion Passenger, but you can also choose a custom Rack server like Unicorn. You may have a web entry in your Procfile to do this on Heroku. Cloud 66 ignores this entry to avoid compatibility issues.

To run a custom web server, we require a custom_web entry. It is important to set this before analyzing your application, to avoid building the application with Passenger.

You can also use the Procfile to define other background jobs.

Dyno recycling

Heroku restarts all dynos at 24 hours of uptime, which may conceal possible memory leaks in your application. When you migrate to Cloud 66, these will become noticeable because we don’t restart your workers (other than during a deployment), so the leak can grow to be bigger. A temporary solution is to re-create the Heroku restart behavior, for example with this script:

for OUTPUT in $(pgrep -f sidekiq); do kill -TERM $OUTPUT; done

This will send a TERM signal to any Sidekiq workers, giving them 10 seconds (by default) to finish gracefully. Any workers that don’t finish within this time period are forcefully terminated and their messages are sent back to Redis for future processing. You can customize this script to fit your needs, and add it to your application as a shell add-in.

Note that this is a temporary solution, and we recommend that you use a server monitoring solution to identify the source of your leak.

Asset Pipeline Compilation

If you haven’t compiled assets locally, Heroku will attempt to run the assets:precompile task during slug compilation. Cloud 66 allows you to specify whether or not to run this during deployment.

What’s next?