SQL Server connectivity issue - 'TCP Provider: Error code 0x68'

[Paul-Eccleston-i2]

I am seeing a repeatable but slightly random error of TCP Provider: Error code 0x68 when running two MS SQL Server Docker containers in the same Docker bridge network.

The first docker container (server) is running as follows:-

  docker run \
    "-d" \
    "--rm" \
    "--platform=linux/amd64" \
    "--network-alias=server.test" \
    "--name=server" \
    "--network=test" \
    "--env=ACCEPT_EULA=Y" \
    "--env=SA_PASSWORD=StrongPassword" \
    "--env=MSSQL_PID=Developer" \
    "--env=MSSQL_AGENT_ENABLED=true" \
    "mcr.microsoft.com/mssql/rhel/server:2022-latest"

The second docker container (client) is running as follows:-

  docker run \
    "--rm" \
    "--platform=linux/amd64" \
    "--network=test" \
    "--name=client" \
    -v "<host path to scripts>:<container path to scripts>" \
    "mcr.microsoft.com/mssql/rhel/server:2022-latest" \
    bash -c "set -e; ${test_command}"

The following is the test command executed:-

test_command="${1:-"/opt/mssql-tools/bin/sqlcmd -S server.test -U sa -P StrongPassword -N -C -i '<sql scripts to run>'"}"

Things I have tried:-

• Verified RAM usage is acceptable on the host (32GB total, around 22GB in use)
• Tried different Microsoft SQL images
• Ensured no packages are being updated in the base OS (seemed to fix the issue my preventing certain packages from installing, but this no longer works)
• Tried ruling out scripts, but at this point it does not seem to be a single script causing the issue.
• Looked at the SQL Server container logs - nothing of interest is shown, no errors are logged.

So I am at a loss as to the cause of the issue at this point, it seems to me to be network connectivity related, but I see nothing obviously wrong with the above, does anybody have any suggestions on how I can try and debug this further, if you need any further information then please let me know.