increase max_allowed_packet size in mysql docker

Question

We are using Docker for mysql, We are facing the below error while running

Packet for query is too large (12884616 > 4194304). You can change this value on the server by setting the max_allowed_packet' variable.; nested exception is com.mysql.jdbc.PacketTooBigException: Packet for query is too large (12884616 > 4194304). You can change this value on the server by setting the max_allowed_packet' variable.

now we need to increase max_allowed_packet size in mysql configuration, Can anyone help me on docker command to increase max_allowed_packet.

Solution 1

As an argument to the container command:

docker run -it -e MYSQL_ROOT_PASSWORD=my-secret-pw mysql:5.7 --max-allowed-packet=67108864

See "Configuration without a cnf file" at https://hub.docker.com/_/mysql/, copied here for posterity:

Configuration without a cnf file Many configuration options can be passed as flags to mysqld. This will give you the flexibility to customize the container without needing a cnf file. For example, if you want to change the default encoding and collation for all tables to use UTF-8 (utf8mb4) just run the following:

$ docker run --name some-mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci

If you would like to see a complete list of available options, just run:

$ docker run -it --rm mysql:tag --verbose --help

When using docker-compose (as asked in the comments), add a command key with the arguments:

version: "3"
services:
  data:
    image: "mysql:5.7.20"
    command: --max_allowed_packet=32505856      # Set max_allowed_packet to 256M (or any other value)
    environment:
      - MYSQL_ROOT_PASSWORD=password
      - MYSQL_DATABASE=db
      - MYSQL_USER=user
      - MYSQL_PASSWORD=user_password

Solution 2

When using docker-compose (as asked in the comments), add a command key with the arguments, for example:

version: "3"
services:
  data:
    image: "mysql:5.7.20"
    # Set max_allowed_packet to 256M (or any other value)
    command: --max_allowed_packet=32505856
    environment:
      - MYSQL_ROOT_PASSWORD=password
      - MYSQL_DATABASE=db
      - MYSQL_USER=user
      - MYSQL_PASSWORD=user_password

Whilst this works for the MySQL docker images, it may not work for all is it overwrites the default command.

More info: Docker Compose - Command

Solution 3

I think you should modify it in your Dockerfile like this :

RUN sed -ire 's/max_allowed_packet.*=.*/max_allowed_packet = YOURVALUE/g' /etc/mysql/my.cnf

Comments

[Admin]

Any help in docker compose file ?

[Tan Dat]

Do I have to rebuild with the docker-compose file? or What should I do next? run docker-compose down and then up again?

[Mike Hill]

@TanDat yes, you will need to reconfigure the service using docker-compose down and docker-compose up like you stated.

[Sharak]

I find it essential with sql imports to also ensure proper connection and database encoding. For that it's best to change command to this: command: [ "--character-set-server=utf8mb4", "--collation-server=utf8mb4_unicode_ci", "--init-connect='SET NAMES utf8mb4'", "--max-allowed-packet=67108864" ] and add another environment parameter: - LANG=C.UTF-8

[Hua Zhang]

It works in my docker compose file. Thanks!