How to Run Different MySQL versions on the Same Server

Multiple MySQL versions running on one server

There are many situations where there is a require where you need to run multiple instances of MySQL on same machine.

Some situations are:

• test a new MySQL release while leaving an existing production setup undisturbed
• give different users access to different mysqld servers that they manage themselves

The Problem

I have a machine with 5 products already setup. All products are using MySQL 5.5 as their default database. Now it's time to upgrade all but one product to use MySQL 5.6. The table below shows the before and after version requirements of MySQL for various products. Looking at the table, we find that all products except product C wants to use MySQL 5.6.

Since all but one products require MySQL 5.6, let's install it first and then we will work to figure out a way to install MySQL 5.5 as well.

Installing MySQL 5.6

sudo apt-get update
sudo apt-get install mysql-server-5.6 mysql-server-core-5.6 mysql-client-5.6 mysql-client-core-5.6

At this point, we have MySQL 5.6 listening at port 3306 (default port)

Approach to solution

There are several approaches with which you can achieve multiple MySQL versions running on the same machine. Some of them are

• Use binaries of specific version
• Build everything from MySQL source

Issues in above approaches:

Evidently, we can only have one version of MySQL setup on the machine using default installation procedure with apt-get. Hence, if we try to install one version over other, it will replace the first version and will retain the second version. Thus, we cannot have 2 versions of MySQL using the default installation procedure.

Building everything from scratch involves a lot of complications at source level. In order to debug any issues that might arise, you should be aware of what happens in various scripts/commands that you run. I did spend a day in building from the source, but it eventually turned out to be complete waste of time, effort and debugging.

Docker to the rescue

If we had a container in which we have a MySQL 5.5 installed and if we can publish the container's port(s) to the host, then we can connect to container's MySQL just like a local database.

We can have all of the above with Docker. If you don't know what docker is, please read this official documentation.

Installing Docker

To install Docker on your machine, execute following command on your shell.

curl -sSL https://get.docker.com/ | sh

Spin off MySQL 5.5 container

Execute following command; this will download MySQL 5.5 image and will spin off the container. This container will have MySQL 5.5 installed on port 3306. But on the host machine, port 3310 will be forwarded.

sudo docker run --name mysql-55-container -p 127.0.0.1:3310:3306 -e MYSQL_ROOT_PASSWORD=rootpassword -d mysql:5.5

NOTE: Password for the root user is rootpassword; you can change it to anything.

Connect to MySQL 5.5

mysql -u root -p --host=127.0.0.1 --port=3310

Connect to MySQL 5.6

mysql -u root -p

And voila! you have both My SQL 5.5 and MySQL 5.6 installed and running on same machine.

Now you can configure your application product C to use host 127.0.0.1 and port 3310 and thus you have products A, B, D and E running on MySQL 5.6 and product C running on MySQL 5.5.