Resolve Docker MySQL crashes

What

Cause docker MySQL default lib has minimal memory settings for their performance.

It makes very frustrating crashes often.

So many of use case of this lib should add more ‘max_allowed_packet’ with ‘key_buffer_size’

How

1. make a custom MySQL config file

mkdir mysqlconf && cd mysqlconf && vim gatewaymy.cnf

add below to gateway.cnf

[mysqld]
max_allowed_packet = 64M
key_buffer      = 64M

2. Add custom MySQL config to your docker-compose.yml file

volumes:
- ./mysqlconf:/etc/mysql/conf.d

./mysqlconf 👈 means relative path from your docker-compose.yml file

(example)

3. check configuration is applied

connect to MySQL container

docker-compose up -d && docker exec -it wordpress_wordpress_db_1 bash

check ‘max_allowed_packet’

mysql -p -e "show variables like '%max_allowed_packet%';"

check ‘key_buffer’

mysql -p -e "show variables like '%key_buffer%';"

Ref

Add Custom my.cnf Settings to MySQL Container — CA API Gateway — 9.1 — CA Technologies…

mysql immediately stops after running · Issue #3 · docker-library/mysql