The latest Docker preview image breaks MySQL that contains multiple stataments (such as set variable)

[myonlylonely]

Issue Summary

The latest Docker preview image breaks MySQL that contains multiple stataments. Reverting back to the previous preview image solves the problem.

Steps to Reproduce

1. Write a MySQL query that contains mutiple statements.

set @var_1 = 123;
select * from test_table;

2. Execute the query, then it returns Error running query: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select * from test_table' at line 2.

3. Executing the first or the second statements alone works fine.

4. Reverting to the old Docker preview image also works fine.

Technical details:

• Redash Version: 11.0.0-dev (28b0a23)
• Browser/OS: Chrome 111.0.5563.64/macOS 13.2.1
• How did you install Redash: Docker

[myonlylonely]

I have found the cause, the version string returned from _mysql.get_client_info() is different, and is lower than 4 in the latest Docker image.

import _mysql
logger.info(_mysql.get_client_info())

The above code print 3.1.20 in the latest Docker image, but 10.3.36 in the previous Docker Image.
mysqlclient 1.3.14 has the following code (https://github.com/PyMySQL/mysqlclient/blob/1.3.14/MySQLdb/connections.py)

client_flag = kwargs.get('client_flag', 0)
client_version = tuple([ numeric_part(n) for n in _mysql.get_client_info().split('.')[:2] ])
if client_version >= (4, 1):
  client_flag |= CLIENT.MULTI_STATEMENTS
if client_version >= (5, 0):
  client_flag |= CLIENT.MULTI_RESULTS

kwargs2['client_flag'] = client_flag

So it does not enable MULTI_STATEMENTS and MULTI_RESULTS flags.
Manually pass the client_flag parameter works fine.

def _connection(self):
  params = dict(
  # other param
    client_flag=MULTI_STATEMENTS | MULTI_RESULTS,
  )
  # other code
  connection = MySQLdb.connect(**params)

  return connection

But I wonder why it is different in the newest Docker image? I guess it has something to do with the dependency issues?
@arikfr

[arikfr]

Did you build the Docker image locally?

[myonlylonely]

Did you build the Docker image locally?

No, I use the Docker image from official Docker hub.I tried the latest preview image, it does not work, but previous preview image works (published 6 months ago).

[arikfr]

My best guess is that something went wrong with the Docker build and it's using an old mysql client version. We're going to fix the build soon🤞, so maybe we can wait for a new image to test this again?

[myonlylonely]

Sure, please let me know when the new image is ready for testing.

[myonlylonely]

My best guess is that something went wrong with the Docker build and it's using an old mysql client version. We're going to fix the build soon🤞, so maybe we can wait for a new image to test this again?

It may has something to do with mariadb-client changes. https://jira.mariadb.org/browse/CONC-488.

It says

When old GPL licensed libmysql was replaced by MariaDB Connector/C (10.2 and above) we changed the version number to the corresponding server version to prevent breakage of existing applications.

In the new preview Docker image the client version is 10.3, and the old one is using 10.1. So it may be related to that.

[myonlylonely]

@arikfr
Could we bump the version of mysqlclient to a newer version, as the latest version does not require check the mysql client lib version to enable MULTI_STATEMENTS flag.
Or we could manually pass the client_flag parameter to the connection to stay at current version?
Either way, I could make a pull request.

[arikfr]

@myonlylonely yes, we can. The plan is to upgrade all dependencies once we have CI properly running again. But you can create a PR to update the client ahead of this.

Are there any limitations in terms of what MySQL version it can connect to with the new client?

[myonlylonely]

@arikfr Not that I know of. I have already made a pull request to bump the mysqlclient version. #5957

[justinclift]

... once we have CI properly running again.

@arikfr What's the plan of action for that bit?

[arikfr]

@justinclift switch to GitHub Actions.