You can choose between two different approaches to determine the cause of problems in the behavior of your application: source-language debugging or interactive debugging.

For source-language debugging, COBOL provides several language elements, compiler options, and listing outputs that make debugging easier.

If the problem with your program is not easily detected and you do not have a debugger available, you might need to analyze a storage dump of your program.

For interactive debugging, you can use Start of changez/OS® DebuggerEnd of change. Start of changez/OS DebuggerEnd of change offers these productivity enhancements:

  • Interactive debugging (in full-screen or line mode), or debugging in batch mode

    During an interactive full-screen mode session, you can use the full-screen services and session panel windows on a 3270 device to debug your program while it is running.

  • COBOL-like commands

    For each high-level language supported, commands for coding actions to be taken at breakpoints are provided in a syntax similar to that programming language.

  • Mixed-language debugging

    You can debug an application that contains programs written in a different language. Start of changez/OS DebuggerEnd of change automatically determines the language of the program or subprogram being run.

  • COBOL-CICS® debugging

    Start of changez/OS DebuggerEnd of change supports the debugging of CICS applications in both interactive and batch mode.

  • Support for remote debugging

    Start of changeYou can used the Eclipse-based debug interface and IBM Z® Open Debug to debug programs that run on z/OS.End of change

Note: Start of changeStart of changeIBM® z/OS DebuggerEnd of change is a common component that is provided in the following products:
  • IBM Debug for z/OS, previously known as IBM Debug Tool for z/OS
  • IBM Developer for z/OS, previously known as IBM Developer for z Systems® and Rational® Developer for z Systems
  • IBM Developer for z/OS (Enterprise Edition), which is also provided with the IBM Application Delivery Foundation for z/OS bundle
  • Start of changeIBM Z and Cloud Modernization StackEnd of change

Start of changeThe debug features provided in different products vary. For more information, see Overview of IBM z/OS Debugger.End of change

Depending on the level of Enterprise COBOL that you are using to create the COBOL application, update your debugger to a certain version:
  • z/OS Debugger 15.0.5 and later supports Enterprise COBOL 6.4 and earlier versions
  • z/OS Debugger 14.2 and later supports Enterprise COBOL 6.3 and earlier versions
  • z/OS Debugger 14.1 supports Enterprise COBOL 6.2 and earlier versions
  • z/OS Debugger 14.0 supports Enterprise COBOL 6.1 and earlier versions
  • Debug Tool 13.1 supports Enterprise COBOL 5.1 and earlier versions
End of change

Related references  
IBM z/OS Debugger Reference and Messages
Language Environment® Debugging Guide (Formatting and analyzing system
   dumps, Debugging example COBOL programs)