MySQL Router Connection Attributes Failed

Question

I have a 3 node innodb cluster setup. On each server I also have a mysql router. I bootstrapped 1 of the routers. Started all 3 routers using the same conf that was created during the bootstrap. I am seeing the following warning in the mysql router logs.

2111: decoding connection attributes failed [ignored]: (input too short)

My first thought was that I should have bootstrapped each mysql router and created their own config. Not sure if that is right way to do it? Also, has anyone else seen this warning before? Is it harmless or should I be worried?

running mysql server 8.0.29 and mysql router 8.0.29

UPDATE I was able to isolate the connection. The problem connection is coming from Grafana. I reviewed the connection string there, but everything looks correct.

TIA

Answer 1

I had similar problem, and I figured out that in version 8.0.23 there was added router<->client TLS endpoint support and also changed client_ssl_mode default behaviour.

The default behavior changed from client_ssl_mode = PASSTHROUGH to client_ssl_mode = PREFERRED where PASSTHROUGH forwards everything to the server and lets the client and server decide TLS settings, whereas PREFERRED establishes TLS connections between the client and Router if the client desires switching to TLS if the server supports TLS. This also matches the existing behavior for client and server without the Router in-between.

https://dev.mysql.com/doc/relnotes/mysql-router/en/news-8-0-23.html

Bootstrap process now adds these options to config file:

• client_ssl_cert
• client_ssl_key
• client_ssl_mode

example: https://dev.mysql.com/doc/mysql-router/8.0/en/mysql-router-configuration-file-example.html

commenting them out should hotfix your problem.

Please review available configuration options and decide which TLS configuration suits best for your case.

https://dev.mysql.com/doc/mysql-router/8.0/en/mysql-router-configuration-tls.html