DB2 Communication Error

Question

We recently developed an application which will run a query in DB2 and send a mail to the corresponding recipient. It works well in our local system and QA region. But in production, few queries failed (even if it's rare, like once in week). It throws the exception below.

Exception InnerDetails:

ERROR [40003] [IBM][CLI Driver] SQL30081N A communication error has been detected. Communication protocol being used: "TCP/IP". Communication API being used: "SOCKETS". Location where the error was detected: "111.111.111.111". Communication function detecting the error: "recv". Protocol specific error code(s): "10004", "", "". SQLSTATE=08001

Since error occurs only in production and not very often, we are not sure whether it is the code or a setting issue. Do you have any idea?

Answer 1

That particular error (SQL30081N) is just a generic message that indicates a network issue between your DB2 client and the server. In this case, you want to look at the Protocol specific error code(s). Here, it looks like you're on Windows, and that particular code (10004) isn't given in the IBM documentation.

So, if you google "windows network error codes", you'll find this page, which says:

WSAEINTR

10004

Interrupted function call.

A blocking operation was interrupted by a call to WSACancelBlockingCall.

Which links to this page with more information on that specific function (emphasis mine):

The WSACancelBlockingCall function has been removed in compliance with the Windows Sockets 2 specification, revision 2.2.0.

The function is not exported directly by WS2_32.DLL and Windows Sockets 2 applications should not use this function. Windows Sockets 1.1 applications that call this function are still supported through the WINSOCK.DLL and WSOCK32.DLL.

Blocking hooks are generally used to keep a single-threaded GUI application responsive during calls to blocking functions. Instead of using blocking hooks, an applications should use a separate thread (separate from the main GUI thread) for network activity.

I'm guessing that your application may be blocking for a longer time in your production application than your other environments, and something along the way is causing the interrupt.

Hopefully this leads you down the right path...