Bug #71346 Manual does not provide details on mysqladmin debug output
Submitted: 11 Jan 2014 15:36 Modified: 24 Mar 2017 7:56
Reporter: Valeriy Kravchuk Email Updates:
Status: Won't fix Impact on me:
None 
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:5.6 OS:Any
Assigned to: Paul Dubois CPU Architecture:Any
Tags: missing manual, mysqladmin

[11 Jan 2014 15:36] Valeriy Kravchuk
Description:
Manual (http://dev.mysql.com/doc/refman/5.6/en/mysqladmin.html) does not provide any useful details about the use and output of mysqladmin debug command. It says:

"debug

Tell the server to write debug information to the error log. Format and content of this information is subject to change."

Indeed, change happens, for example when events were added new section about events appeared (and it was somewhat documented on a separate page). But the rest of information does not change with every minor release usually, so why not to document things that are NOT going to change any time soon?

Some sections are obvious, but others, like list of locks or this one:

Alarm status:
Active alarms:   0
Max used alarms: 0
Next alarm time: 0

surely have to be explained.

How to repeat:
Run mysqladmin debug, find something like this:

Current locks:
lock: 0x1a838e70:

lock: 0x1ac28900:

lock: 0x1ad0bff0:
...

Alarm status:
Active alarms:   0
Max used alarms: 0
Next alarm time: 0

in the error log and then try to find out what is it about in the manual (http://dev.mysql.com/doc/refman/5.6/en/mysqladmin.html or elsewhere).

Suggested fix:
Document typical content of mysqladmin debug output, as we as how to use it in most typical cases.
[11 Jan 2014 16:44] Shane Bester
For what it's worth, I filed an internal FR to get rid of this altogether.Bug 16498236 - REPLACE COM_DEBUG COMMAND WITH SENSIBLE ALTERNATIVE. 

"(2) COM_DEBUG command can be used to provide this information.
but, the information is mostly useless, and has caused many concurrency bugs
in the printout of the information.  We need to replace it with appropriate
performance_schema or information_schema tables."
[13 Jan 2014 10:29] Umesh Shastry
Hello Valeriy,

Thank you for the bug report. 

Thanks,
Umesh
[26 Nov 2014 15:26] Paul Dubois
GIven Shane's feature request, which is a better way to deal with this issue, I am closing this docs bug with "Won't Fix."
[24 Mar 2017 7:56] Valeriy Kravchuk
Two years passed and new feature is still not implemented. In the meantime, the output generated by all GA versions of MySQL remains not documented at all. Well done!