MySQL Bugs: #94015: Cannot re-boostrap mysql router when it is running since 8.0.14

Bug #94015	Cannot re-boostrap mysql router when it is running since 8.0.14
Submitted:	23 Jan 2019 9:38	Modified:	22 Feb 2019 22:57
Reporter:	Guillaume Bienkowski	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Router	Severity:	S3 (Non-critical)
Version:	8.0.14	OS:	Debian (stretch)
Assigned to:		CPU Architecture:	x86 (amd64)

Description:
Since 8.0.14, executing `mysqlrouter --bootstrap` on a configured router will not work.

We used to be able to re-bootstrap the router while the service was running. This is not the case anymore: we now need to stop the service, bootstrap, then restart the service.

For completeness, we re-bootstrap regularly because our ansible role does it and it used to be of no consequences.

Downgrading manually to 8.0.13, we are able to re-bootstrap normally.

How to repeat:

- Install mysqlrouter
- Bootstrap it on a running cluster
- Verify that you can connect locally (mysql -uxx -pyy -h 127.0.0.1 -P 6446)
- Re issue the bootstrap command while the router is running (shouldn't change much, creates a new unique id)
- Restart the router 
- Verify that the router cannot connect anymore to the distant cluster.

The only way to get out of this is to 
- stop the service, 
- bootstrap while the service is down, and then 
- restart it.

For reference, when the router is re-bootstraped and doesn't work, you get this message when trying to connect locally:

root@testvm:/home/ansible# mysql -u xxx -pyyy -h 127.0.0.1 -P 6446 
ERROR 2003 (HY000): Can't connect to remote MySQL server for client connected to '0.0.0.0:6446'

Hello Guillaume,

Thank you for the report and feedback.
Verified as described.

regards,
Umesh

Posted by developer:
 
Fixed as of the upcoming MySQL Router 8.0.16 release, and here's the changelog entry:

It was not possible to re-boostrap Router while it was running. Instead,
stopping the service beforehand was required.

Thank you for the bug report.