What is EIBRESP in CICS?

EIBRESP (Execute Interface Block Response) is a field that contains the response code after a CICS command execution. It indicates success (0) or various error conditions that need to be handled by the application.

How do you check for CICS errors in COBOL?

After each EXEC CICS command, check the EIBRESP field. If it's not 0, handle the error appropriately using IF statements or EVALUATE constructs to provide specific error handling for different response codes.

What is the difference between EIBRESP and EIBRESP2?

EIBRESP contains the primary response code, while EIBRESP2 contains additional error information or subcodes that provide more specific details about the error condition.

How do you handle file errors in CICS?

Check EIBRESP after file operations (READ, WRITE, DELETE). Common file errors include 'not found' (EIBRESP = 13), 'duplicate key' (EIBRESP = 22), and 'end of file' (EIBRESP = 20).

What is exception handling in CICS?

Exception handling involves anticipating and gracefully managing error conditions. This includes checking response codes, providing user-friendly error messages, logging errors, and implementing recovery mechanisms.

CICS Error Handling

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Error handling is a critical aspect of CICS application development. Understanding how to properly handle errors, interpret response codes, and implement robust exception handling mechanisms is essential for building reliable mainframe applications.

What is CICS Error Handling?

CICS error handling is the systematic approach to detecting, analyzing, and responding to errors that occur during program execution. Unlike modern programming languages with try-catch blocks, CICS uses response codes and conditional logic to manage error conditions.

Think of CICS error handling like a traffic light system. Each CICS command returns a response code (like a traffic light color), and your program must check this code and take appropriate action (like stopping, proceeding with caution, or taking an alternate route).

Key Components of CICS Error Handling:

EIBRESP: Primary response code indicating success or failure
EIBRESP2: Secondary response code with additional error details
Exception Handling: Program logic to manage error conditions
Error Recovery: Mechanisms to restore normal operation
User Communication: Informing users about errors and next steps

Response Codes and Their Meanings

CICS response codes are numeric values that indicate the result of command execution. Understanding these codes is fundamental to effective error handling.

Common Response Codes:

Code	Meaning	Description	Action Required
0	Normal	Command completed successfully	Continue processing
4	Warning	Command completed with warnings	Check for potential issues
8	Error	Command failed	Handle error condition
12	Program Error	Program logic error	Debug and fix program
13	Not Found	Record or resource not found	Check search criteria
20	End of File	Reached end of file	Normal condition for sequential reads
22	Duplicate Key	Key already exists	Handle duplicate condition

Basic Error Handling in COBOL

In COBOL, error handling is implemented using conditional statements that check the EIBRESP field after each CICS command. This approach ensures that errors are caught and handled appropriately.

Standard Error Handling Pattern:

cobol

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. ERROR-HANDLING-EXAMPLE.
       
       ENVIRONMENT DIVISION.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  CUSTOMER-RECORD.
           05  CUST-ID        PIC X(10).
           05  CUST-NAME      PIC X(30).
           05  CUST-BALANCE   PIC 9(7)V99.
       
       01  EIBRESP           PIC S9(8) COMP.
       01  EIBRESP2          PIC S9(8) COMP.
       
       PROCEDURE DIVISION.
       
       MAIN-LOGIC.
           PERFORM READ-CUSTOMER
           PERFORM PROCESS-CUSTOMER
           PERFORM WRITE-CUSTOMER
           STOP RUN.
       
       READ-CUSTOMER.
           EXEC CICS READ
               DATASET('CUSTFILE')
               INTO(CUSTOMER-RECORD)
               RIDFLD(CUST-ID)
               RESP(EIBRESP)
               RESP2(EIBRESP2)
           END-EXEC
           
           IF EIBRESP NOT = 0
               PERFORM HANDLE-READ-ERROR
           END-IF.
       
       HANDLE-READ-ERROR.
           EVALUATE EIBRESP
               WHEN 13
                   DISPLAY 'Customer not found: ' CUST-ID
               WHEN 20
                   DISPLAY 'End of file reached'
               WHEN OTHER
                   DISPLAY 'Read error: ' EIBRESP
           END-EVALUATE.

This example demonstrates the fundamental pattern of CICS error handling in COBOL:

Check EIBRESP: After each CICS command, examine the response code
Conditional Logic: Use IF statements or EVALUATE to handle different error conditions
Specific Handling: Provide different responses for different error types
Error Procedures: Separate procedures for handling specific error conditions

Advanced Error Handling Techniques

Beyond basic response code checking, advanced error handling techniques provide more sophisticated ways to manage errors and improve application reliability.

1. Error Logging and Recovery:

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       WORKING-STORAGE SECTION.
       01  ERROR-LOG.
           05  ERROR-TIME     PIC X(8).
           05  ERROR-COMMAND  PIC X(16).
           05  ERROR-RESP     PIC S9(8) COMP.
           05  ERROR-RESP2    PIC S9(8) COMP.
           05  ERROR-MESSAGE  PIC X(80).
       
       PROCEDURE DIVISION.
       
       LOG-ERROR.
           MOVE FUNCTION CURRENT-DATE TO ERROR-TIME
           MOVE 'READ' TO ERROR-COMMAND
           MOVE EIBRESP TO ERROR-RESP
           MOVE EIBRESP2 TO ERROR-RESP2
           
           EXEC CICS WRITE
               DATASET('ERRORLOG')
               FROM(ERROR-LOG)
               RESP(EIBRESP)
           END-EXEC.
       
       RECOVERY-ATTEMPT.
           IF EIBRESP = 13
               PERFORM RETRY-WITH-ALTERNATE-KEY
           ELSE IF EIBRESP = 22
               PERFORM GENERATE-NEW-KEY
           ELSE
               PERFORM ABEND-PROCESSING
           END-IF.

2. User-Friendly Error Messages:

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       WORKING-STORAGE SECTION.
       01  USER-MESSAGE      PIC X(79).
       01  ERROR-DETAILS     PIC X(79).
       
       PROCEDURE DIVISION.
       
       DISPLAY-USER-ERROR.
           EVALUATE EIBRESP
               WHEN 13
                   MOVE 'Customer not found. Please check the ID and try again.' 
                       TO USER-MESSAGE
               WHEN 22
                   MOVE 'A customer with this ID already exists. Please use a different ID.' 
                       TO USER-MESSAGE
               WHEN 8
                   MOVE 'System temporarily unavailable. Please try again later.' 
                       TO USER-MESSAGE
               WHEN OTHER
                   MOVE 'An unexpected error occurred. Please contact support.' 
                       TO USER-MESSAGE
           END-EVALUATE
           
           EXEC CICS SEND
               FROM(USER-MESSAGE)
               LENGTH(79)
               ERASE
           END-EXEC.

3. Transaction Rollback and Recovery:

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       PROCEDURE DIVISION.
       
       PROCESS-TRANSACTION.
           PERFORM UPDATE-CUSTOMER
           IF EIBRESP NOT = 0
               PERFORM ROLLBACK-TRANSACTION
               PERFORM NOTIFY-USER-OF-FAILURE
           ELSE
               PERFORM COMMIT-TRANSACTION
               PERFORM NOTIFY-USER-OF-SUCCESS
           END-IF.
       
       ROLLBACK-TRANSACTION.
           EXEC CICS SYNCPOINT
               ROLLBACK
               RESP(EIBRESP)
           END-EXEC
           
           IF EIBRESP NOT = 0
               PERFORM LOG-ROLLBACK-FAILURE
           END-IF.
       
       COMMIT-TRANSACTION.
           EXEC CICS SYNCPOINT
               RESP(EIBRESP)
           END-EXEC.

Best Practices for Error Handling

Following established best practices ensures that your CICS applications handle errors consistently and provide a better user experience.

Error Handling Best Practices:

Always Check Response Codes

Check EIBRESP after every CICS command, even if you expect success.

Provide Meaningful Error Messages

Give users clear, actionable information about what went wrong and how to proceed.

Implement Proper Logging

Log all errors with sufficient detail for debugging and monitoring purposes.

Use Transaction Management

Implement proper commit/rollback mechanisms to maintain data consistency.

Common Mistakes to Avoid:

Mistake	Problem	Solution
Ignoring EIBRESP	Program continues with invalid data	Always check response codes
Generic error handling	Poor user experience and debugging	Handle specific error types
No error logging	Difficult to troubleshoot issues	Implement comprehensive logging
Missing rollback	Data inconsistency	Use SYNCPOINT ROLLBACK

CICS Error Handling

What is CICS Error Handling?

Key Components of CICS Error Handling:

Response Codes and Their Meanings

Common Response Codes:

Basic Error Handling in COBOL

Standard Error Handling Pattern:

Advanced Error Handling Techniques

1. Error Logging and Recovery:

2. User-Friendly Error Messages:

3. Transaction Rollback and Recovery:

Best Practices for Error Handling

Error Handling Best Practices:

Always Check Response Codes

Provide Meaningful Error Messages

Implement Proper Logging

Use Transaction Management

Common Mistakes to Avoid:

Quick Quiz

Question 1: What does EIBRESP = 0 indicate?

Question 2: Which response code indicates "not found"?

Question 3: What is the purpose of EIBRESP2?

Related Concepts and Pages

Related Concepts

EIBRESP Response Codes

Exception Handling

Transaction Management

Related Pages