From: Bill K
Date: January 17 2007 3:24pm
Subject: Re: Lost connection to MySQL server during query
List-Archive: http://lists.mysql.com/plusplus/6296
Message-Id: <45AE3FAF.2060300@billism.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Hello Roger,

I also have this problem, in a mult-threaded environment as you 
described. I searched for a solution all over and went through all the 
possibilities found on the mysql web site and others. It is definitely 
not a timeout, as is said to be the most common reason for this 
exception. I found no solution.

The work-around that I did was code the app to call ping() on the 
connection object after that exception was thrown and then put the query 
back in the query queue I have setup, which is then promptly processed 
just fine. I even use the 'reconnect' and 'multi_statement' (needed 
anyway for stored procedures) options. ping() will test and reconnect 
the connection.

Not a fix by any means but at least it gets the job done, and just ever 
so slightly slower, as like you said, it happens every 50 or 100 queries 
or so.

Note: Using MySql 5.20 and the release of MySql++ 2.1.1. If I remember 
correctly, this problem started happening when I started using stored 
procedures.

- Bill K.


Urscheler, Roger (COM Chantry CA) wrote:
> Hi,
>
> I have a multi-threaded application with a threadpool where each thread has
> its own connection (and query and row objects). I did set the 'reconnect'
> and 'multi statement' options. Once a while (about every 50 or 100 queries)
> the connection to mysql is disconnected, the exception is "Lost connection
> to MySQL server during query". The 'reconnect' option reconnects
> automatically again, but still this query failed.
>
> Does anybody know about this problem?
>
> Thanks,
> Roger
>
>
>