MySQL Bugs: #12674: Instance Manager: IM doesn't handle client connections correctly

Bug #12674	Instance Manager: IM doesn't handle client connections correctly
Submitted:	19 Aug 2005 12:38	Modified:	4 Mar 2006 0:25
Reporter:	Alexander Nozdrin	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Instance Manager	Severity:	S3 (Non-critical)
Version:	5.0	OS:
Assigned to:	Petr Chardin	CPU Architecture:	Any

Description:
Sometimes when working with Instance Manager from 'mysql' (cmd-line tool), the following error appears:

ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    4
Current database: *** NONE ***

I'm not absolutely sure, but it looks as if Instance Manager has some timeout per connection. When the timeout expires, Instance Manager closes connection. So, when mysql tries to send next command it discovers that connection is closed.

How to repeat:
1. Start Instance Manager;
2. Start 'mysql' and connect to the Instance Manager;
3. Execute any command (SHOW INSTANCES, for one);
4. Wait some time (5 minutes is absolutely enough);
5. Execute any command again (SHOW INSTANCES). The error should appear.
In the Instance Manager's log connection identifier should be increased (means that IM opens a new connection);

Thank you for a bug report. I was able to verify on IM from the latest 5.0.16-BK just as described:

[openxs@Fedora 5.0]$ libexec/mysqlmanager >/dev/null 2>&1 &
[1] 16072
[openxs@Fedora 5.0]$ bin/mysql -uvk -p --socket=/tmp/mysqlmanager.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 0.2-alpha

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> show instances;
+---------------+---------+
| instance_name | status  |
+---------------+---------+
| mysqld        | offline |
+---------------+---------+
1 row in set (0,00 sec)

... waited for about 10 minutes here

mysql> show instances;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...

Is the timeout not currently configurable via the my.cnf?

Is the timeout not currently configurable via the my.cnf?

i've noticed this as well.

perhaps when being designed it was assumed someone wouldn't be logged in to the IM for a long time?

i'd say as a feature request the timeout can be set, just like with the normal mysql server's client... but i wouldn't consider it to be a high priority (since it auto-reconnects)

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/2939

Approved over email.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/2969

I've added an option to the Instance Manager:
--wait-timeout. It allows to set the number of seconds, IM waits 
for activity on a connection before closing it.
The default is also increased to be 8hrs (as in the server)
puhsed into 5.0.18

5.0.18 is released, 5.0.19 of course.

Noted in 5.0.19 changelog.

Added the <option>--wait-timeout</option> option to
<command>mysqlmanager</command> to allow configuration of the
timeout for dropping an inactive connection, and increased the
default timeout from 30 seconds to 28,800 seconds (8 hours).
(Bug #12674)