Troubleshooting DRDA and DDM

When a problem occurs accessing a distributed relational database, determine the nature of the problem and whether it is a problem with the application or a problem with the local or remote system.

To resolve a problem or obtain customer support assistance to resolve the problem, you need the following skills:

An understanding of the IBM® i licensed program
An idea about whether the problem is on a client or a server
Familiarity using IBM i problem management functions

For more information about diagnosing problems in a distributed relational database, see the Distributed Relational Database Problem Determination Guide, SC26-4782.

IBM i problem handling overview
The IBM i licensed program helps you manage problems for both user-detected and system-detected problems that occur on local and remote System i® platforms.
System and communications problems
When a problem with a system or its communications occurs, a message is generated. System-detected problems are automatically entered into the problem log, where they can be viewed and analyzed.
DRDA application problems
The best time to handle a problem with an application is before it goes into production. However, it is impossible to anticipate all the conditions that will exist for an application when it gets into general use.
Finding first-failure data capture data
You can use the tips in this topic to locate first-failure data capture (FFDC) data on the IBM i operating system. The information is most useful if the failure causing the FFDC data output occurred on the server. The FFDC data for a client can usually be found in one of the spooled files associated with the job running the application program.
Getting data to report a failure
The IBM i licensed program provides data that you can print to help you diagnose a problem in a distributed relational database.
Starting a service job to diagnose application server problems
When an application uses Distributed Relational Database Architecture™ (DRDA), the SQL statements are run in the application server job. Because of this, you might need to start debug or a job trace for the application server job that is running on the IBM i operating system. The technique for doing this differs based on the use of either Advanced Program-to-Program Communication (APPC) or TCP/IP.
Working with distributed relational database users
Investigating a problem usually begins with the user. Users might not be getting the results they expect when running a program or they might get a message indicating a problem. Sometimes the best way to diagnose and solve a problem is to go through the procedure with a user.

Parent topic: Distributed database programming

Related concepts:

DRDA and DDM performance