MySQL Bugs: #931: Two servers can be started on same port on Windows

Bug #931	Two servers can be started on same port on Windows
Submitted:	26 Jul 2003 14:34	Modified:	26 Aug 2003 7:25
Reporter:	Paul DuBois	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	4.0.14 and below	OS:	Windows (Windows)
Assigned to:	MySQL Verification Team	CPU Architecture:	Any

Description:
It's possible to start two servers on Windows with identical options.
(In particular, with the same TCP/IP port.)  The second server
"steals" the port from the first server until it exits.  While the
second server is running, clients connect to it. When the second
server exits, clients once again connect to the first server.

This differs from Unix, on which the second server would
correctly exit with a "can't bind, address in use" error.

How to repeat:
Start one server:

mysqld

Run a client:

mysql

The client will connect to the first server.

Start a second server:

mysqld-opt

Run a client:

The client will connect to the second server. (You can
tell this because you'll see the mysqld-opt status string
when you connect.)

Shut down the server:

mysqladmin shutdown

mysqladmin too will connect to (and shut down) the
second server.

Run a client:

mysql

The client now connects again to the first server.

mysqladmin shutdown now will shut down the first
server.

Thank you for the bug report, a patch was sent for approval.

Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at
    http://www.mysql.com/doc/en/Installing_source_tree.html

The fix will appear in 4.0.15