Bug #19381 occasionally get "MySQL server has gone away"
Submitted: 26 Apr 2006 18:49 Modified: 26 Apr 2006 18:54
Reporter: Hongyi Gao Email Updates:
Status: Duplicate Impact on me:
None 
Category:Connector / ODBC Severity:S1 (Critical)
Version:3.51.12 OS:Microsoft Windows (win2000 (ODBC) & Linux (mysql 4))
Assigned to: CPU Architecture:Any

[26 Apr 2006 18:49] Hongyi Gao
Description:

3 machines -- one win2000 server with mysql ODBC 3.51.06 + two machines with
mysql 4.1.7 and gentoo linux. Worked perfectly.

After we upgrade ODBC 3.51.06 to 3.51.12 on win2000, because one of the mysql server is upgraded to mysql 5.0.16, ODBC 3.51.12 works fine with mysql 5.0.16 server, however, with the other mysql 4.1.7 linux server, the ODBC on win2000 gives us "MySQL has gone away" error ocasionally. Sometimes it is no problem. Sometimes it has this issue. If I kill DLLHOST while it has issue, it will recover.
Meanwhile, the mysql server side logged alot of timeout connections.

How to repeat:
1. Our previous working environment:  
3 machines -- one win2000 server with mysql ODBC 3.51.06 + two machines with
mysql 4.1.7 and gentoo linux. Worked perfectly.

2. changes: 
upgrade ODBC 3.51.06 to 3.51.12 on win2000, because one of the mysql server is
upgraded to mysql 5.0.16

3. issues:
Now, ODBC 3.51.12 works fine with mysql 5.0.16 server, however, with the other
mysql 4.1.7 linux server, the ODBC on win2000 gives us "MySQL has gone away"
error ocasionally. Sometimes it is no problem. Sometimes it has this issue.
Meanwhile, the server side logged alot of timeout connections.

4. challenge:
I don't think this is the timeout issue because both mysql servers (5.0.16 and
4.1.7) are of identical configs. If it is timeout with 4.1.7 machine, it should
have the same problem with 5.0.16 one too. Nor does the network package size
issue (since all of them are set to 16M and my qureies are all small)

5. to repeat:
setup 3 servers as what I described. You will get the fun.
Also, we have a test environment setup this way. If you like, we can open the
access to you and let you help us go through this.

thank you very much. appreciate for your patience.

Suggested fix:
force it to reconnection if it fails?
[26 Apr 2006 18:54] Hongyi Gao
removed because of duplication