In mainframe online transaction processing with CICS, how do you typically handle errors in CICS programs and report conditions back to the application logic?

Introduction / Context:
Customer Information Control System, commonly called CICS, is a transaction processing monitor widely used on IBM mainframes. In CICS applications, proper error handling is critical for reliability and user experience. CICS provides structured mechanisms for detecting abnormal conditions on EXEC CICS commands and for transferring control to error handling routines. This question tests whether you understand how to use RESP codes, RESP2 codes, and CICS HANDLE statements to handle errors cleanly in CICS programs.

Given Data / Assumptions:

• CICS programs are typically written in COBOL, PL/I, or other supported languages with EXEC CICS commands.
• Each EXEC CICS command can return condition codes indicating success or failure.
• The application should detect conditions such as NOTFND, DUPKEY, and PGMIDERR and react appropriately.
• CICS provides RESP and RESP2 options and HANDLE CONDITION or HANDLE ABEND directives to control error flow.
• The goal is robust error handling without shutting down the entire transaction region.

Concept / Approach:
In a CICS program, error handling commonly follows two patterns. The first is to use the RESP and RESP2 options on EXEC CICS commands to capture condition codes immediately after the command executes. The programmer then tests these codes in regular program logic to decide whether to continue, retry, or display an error message. The second pattern is to use HANDLE CONDITION to specify a label to which control should be passed if a specific condition occurs, such as NOTFND or PGMIDERR, and HANDLE ABEND to catch abnormal termination situations. Using these mechanisms, the program can centralize error handling, log problems, and present friendly messages to users instead of abending unexpectedly.

Step-by-Step Solution:
Step 1: For important EXEC CICS commands such as READ, WRITE, SEND, and LINK, specify RESP(resp-var) and RESP2(resp2-var) so that condition codes are returned into variables. Step 2: Immediately after each command, test resp-var for standard CICS response codes like DFHRESP(NORMAL), DFHRESP(NOTFND), or DFHRESP(DUPKEY). If necessary, examine resp2-var for additional detail. Step 3: If the response indicates an error or unusual condition, perform appropriate handling such as setting an error message field on the map, backing out a partial update, or branching to an error paragraph. Step 4: Use HANDLE CONDITION to associate specific conditions (for example, ERROR, NOTFND, MAPFAIL) with paragraph labels in the program, so that CICS can transfer control to those labels when such conditions occur, centralizing the error handling code. Step 5: Optionally, use HANDLE ABEND to catch abnormal ends, log diagnostic information, and issue a user friendly message, before deciding whether to abend the transaction or return control to the user.

Verification / Alternative check:
You can verify this pattern by looking at typical CICS programming examples. Many code samples show EXEC CICS READ with RESP options followed by IF statements on the returned response codes. Similarly, training materials on CICS include examples of HANDLE CONDITION for NOTFND to avoid program abends when a record is missing. This confirms that structured error handling in CICS revolves around RESP, RESP2, HANDLE CONDITION, and HANDLE ABEND, rather than ignoring errors or shutting down the region.

Why Other Options Are Wrong:
Option B is wrong because ignoring return codes leads to unpredictable abends and poor user experience; CICS does not automatically fix application logic errors. Option C is extreme and impractical, as shutting down the entire CICS region for a single transaction error would cause massive disruption. Option D suggests replacing EXEC CICS with plain COBOL I/O, which defeats the purpose of using CICS for transactional control and is not how CICS resources are accessed. Option E prints messages without checking conditions and is not a structured or reliable error handling strategy.

Common Pitfalls:
A common pitfall is failing to code RESP or HANDLE CONDITION, which allows unexpected conditions to cause program abends instead of controlled recovery. Another issue is overusing HANDLE ABEND without proper logging, making problems hard to diagnose. Developers sometimes also treat all non NORMAL responses the same, rather than distinguishing between expected conditions like NOTFND and serious errors. Good CICS error handling carefully decodes RESP and RESP2 values, routes control to appropriate handlers, and leaves the region stable and users informed.

Final Answer:
In CICS, the proper way to handle errors is to use RESP and RESP2 options on EXEC CICS commands and HANDLE CONDITION or HANDLE ABEND directives so that your program can detect specific conditions and execute appropriate recovery or messaging logic instead of abending.