服务器重启后无法连接到 Docker 容器内的 MySQL

Question

I have a DigitalOcean droplet configured with Docker to host a MrSQL database. I am using an open source equivalent to Heroku to manage my containers called Caprover . This has worked excellent for me for months, but I realized that my MySQL database went down due to insufficient memory for InnoDB because my Docker instances were slowly taking up more memory over time. While debugging, I restarted my DigitalOcean droplet using sudo shutdown -r now . After restart (which normally fixes things), my db container logs displayed:

[Note] mysqld: ready for connections.
Version: '5.7.28' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server (GPL)

So at least on the container side it is ready for connections. I hopped back over to Sequel Pro to log back in and I get an immediate connection error:

Unable to connect to host MY_DIGITALOCEAN_IP, or the request timed out.

I have always used the following configuration to log in:

Host: MY_DIGITAL_OCEAN_IP
username: root
password: MY_PASSWORD
Port: 4444

In my container configuration, I have mapped the internal port 3306 to 4444 as seen on my dashboard here:

What are the next steps I need to take to try and debug what is causing this sudden loss of MySQL connection?

Answer 1

有趣的是，第二台服务器重启修复了问题......不知道为什么

Answer 2

I had a similar issue while running mysql in docker. Few things to take into consideration:

1. Increase the memory allocation of docker. 
   You can do it easily using docker desktop dashboard.
2. Run the docker-compose with an admin access.
       For an example: sudo docker-compose -f mysql.docker-compose.yml up -d

Point 2 above will resolve inaccessible file issue.

The above I have done it in my MacBook pro 11.5.1