Bug #93766 MySQL Intermittent Connection Failure ADO 8.0 Uniicode
Submitted: 30 Dec 2018 9:13 Modified: 2 Jan 21:30
Reporter: Simon Leigh Email Updates:
Status: Open Impact on me:
Category:Connector / ODBC Severity:S2 (Serious)
Version: OS:Microsoft Windows (server 12 R2)
Assigned to: CPU Architecture:Any

[30 Dec 2018 9:13] Simon Leigh
MySQL ODBC 8.0 Unicode Driver

Classic ASP / ADO

Connection String
DRIVER={MySQL ODBC 8.0 Unicode Driver}; SERVER=localhost; DATABASE=mydatabase; UID=myuser;PASSWORD=mypassword;

MYSql 8.0.12

A few times a day, connection to the database using ADO returns 'Catastrophic Failure'
This also causes IIS to crash with w3wp.exe in ntdll.dll

We have stripped it back so all the code is doing is connecting to the database. Nothing else.

Connection pooling is off in the odbc driver settings. This is by default, we have not changed anything.
Mysql is not doing anything else on our server.

We can't use this in production because of this issue.

How to repeat:
Create a classic asp page with the following lines.

cst = "DRIVER={MySQL ODBC 8.0 Unicode Driver}; SERVER=localhost; DATABASE=mydatabase; UID=myuser;PASSWORD=mypassword;"
set dbconn = Server.CreateObject("ADODB.Connection")
dbconn.ConnectionTimeout =60
dbconn.CommandTimeout = 60
dbconn.open cst
set dbconn=nothing

Set it to run every few seconds as happens with web traffic.
A few times a day iis will crash (if working properly the app pool will crash and recycle).

Suggested fix:
Please let me know a unicode x64 driver which is know to work without this problem.
[30 Dec 2018 9:57] Simon Leigh
Note that I have upgraded MySQL to 8.0.13 so now both connector and MySQL are 8.0.13 (before connector was 8.0.13 and MySQL was 8.0.12) I will update with whether it makes a difference.
[30 Dec 2018 17:44] Simon Leigh
The problem still occurs with 8.0.13 of both MySQL and connector.
To reproduce, simply set up a website in IIS using MySQL and trap any db connection error. Every few hours it reports a catastrophic failure and also crashes IIS. (Look in the event log for this).

All the code needs to do is connect to a mysql database.

I have also tried in both 64bit and 32bit app pool modes which both give the same problem.

Any ideas for a fix for this?
[2 Jan 21:30] Simon Leigh

I have resolved this by switching to the
5.03.11 MySQL ODBC 5.3 Unicode Driver

Clearly there is a problem with the 8.00.13 MySQL ODBC 8.0 Unicode Driver
As it is crashing IIS.

Not sure if anyone is monitoring this thread, but hopefully you can get it fixed at some point.