Bug #70865 COM_CHANGE_USER redundant packet
Submitted: 8 Nov 2013 23:14 Modified: 12 Nov 2013 17:08
Reporter: Sergei Golubchik Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Connection Handling Severity:S3 (Non-critical)
Version:5.5+ OS:Any
Assigned to: CPU Architecture:Any

[8 Nov 2013 23:14] Sergei Golubchik
Description:
MySQL unnecessary sends plugin_request_packet for every COM_CHANGE_USER packet. Even when a client was already using the correct plugin in the first place. So it asks the client to change from "mysql_native_password" plugin to "mysql_native_password" plugin.

This happens because native_password_authenticate() function sends the generated scramble unconditionally, while it should be sending it only when a scramble was actually generated, not every time.

How to repeat:
connect to mysqld, change user (e.g. with mysqltest), observe the traffic
[12 Nov 2013 17:08] Sinisa Milivojevic
This is verified based on the code inspection as described in the bug report.

Thank you for your report.
[27 Feb 2014 12:31] Andrii Nikitin
may be duplicate of bug 59662