DB2 Communication Error
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
We recently discussed this issue with our IBM rep. After looking in their internal knowledge base, he suggested we add "Interrupt=0" to our connection string, based on recommendations given to other customers that had the same problem.
The default value for Interrupt was 1 before v10.5 FP2 and still is for most connections. They changed the default value to 2 for connections to z/OS (mainframe) in FP2.
We're using C# and the connection string properties for the IBM Data Server Driver for .Net can be found here. I'm sure there is a similar property for their drivers for other languages.
This page from the IBM docs goes into a bit more detail about the setting.
We haven't seen the issue since we recently added the property, but it was always intermittent so I can't yet confidently say that the problem is fixed. Time will tell...