Appendix C. Application Troubleshooting

Troubleshooting database applications is our specialty as DB2 Service Analysts. Problems can occur either because of errors in the application that require debugging, or because of a defect in the DB2 code. DB2 releases Official Fixpaks on a quarterly basis to provide code fixes throughout the product life cycle. All Fixpaks are cumulative, meaning that previous fixes are included in the Fixpak you are installing.

The FTP site for obtaining Fixpaks was listed in the preface. If you explore this site, you will see that each Fixpak directory also has a file called aparlist.txt. This file contains a listing of all the fixes contained in the Fixpak. Each fix is referenced with an identifier known as an APAR. You can search for APARs in the DB2 Technical Library, whose site address is also listed in the preface.

We recommend searching for fixed problems by searching for keywords in the aparlist.txt file and using the DB2 Technical Library. You also can call us at DB2 Technical Support if you suspect a problem is due to a defect. Instructions for applying every Fixpak are included in a readme.txt file. It is important to note that a Fixpak is applicable to problems in the DB2 client run-time code as well as the DB2 server engine, or other components such as GUI tools. For this reason, we suggest regular maintenance on both server and client installations.

The remainder of this chapter focuses on how to do your own troubleshooting, and how to determine if a problem is likely occurring due to an error in the application, a setup problem, or whether a defect in DB2.