MySQL Bugs: #2532: Implications of mysql_ping() autoreconnect not made clear

Bug #2532	Implications of mysql_ping() autoreconnect not made clear
Submitted:	27 Jan 2004 4:04	Modified:	3 Oct 2008 16:54
Reporter:	Tim Bunce	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S2 (Serious)
Version:		OS:	Any
Assigned to:	Paul DuBois	CPU Architecture:	Any

Description:
Implications of mysql_ping() autoreconnect not made clear.

How to repeat:
read http://www.mysql.com/doc/en/mysql_ping.html 

Suggested fix:
http://www.mysql.com/doc/en/mysql_ping.html needs to say load and clear that if the connection was down and reconnected that:

a: you no longer have any locks you may have acquired

b: your old connection may or may not still be running

c: if it is then *it* holds the locks, not you

d: mysql_ping() won't tell you if this has happened so you need to check if mysql_thread_id() has changed.

e: if it has you may want to mysql_kill() the old connection.

f: it would be nice if mysql provided an alternative ping function that:

1: automatically reconnect only if given a flag
2: automatically killed the old one, if given a flag
3: could return the old error code even if it reconnected okay, or perhaps better to leave it available to fetch via mysql_error() etc.

f) should be submitted a feature request, not a doc issue.
Closing this report will not include any action on f).

Peter, please add item f as a worklog idea.

This should not be marked as "won't fix." Auto-reconnect
behavior does need to be documented; it just hasn't
happened yet.

Paul changing the status according your last post:

"This should not be marked as "won't fix." Auto-reconnect
behavior does need to be documented; it just hasn't
happened yet"

Over two years later and this "S2 (Serious)" documentation problem still isn't fixed.

[The docs ccould also say that you can tell if a new connection was made by checking if the thread_id changed]

Stefan, Paul, is there any reason this is still not documented?

Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly, and will be included in the next release of the relevant products.

There is a section in the manual that describes the effects of reconnecting:
http://dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html

I've added some of the information in this bug report (about using thread ID to detect reconnect and that the session might still be running on the server side) to that section and added a cross reference to the section from the mysql_ping() section.