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CICS ISSUE UPDATE - Issue Update

CICS ISSUE UPDATE issues an update operation, enabling update management and output processing in CICS environments. It provides efficient update capabilities for CICS applications.

What is CICS ISSUE UPDATE?

CICS ISSUE UPDATE issues an update operation, enabling update management and output processing. It provides efficient update capabilities, allowing applications to issue update operations.

Command Syntax

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EXEC CICS ISSUE UPDATE
    [RESP(response-code)]
    [RESP2(response-code-2)]
END-EXEC.

Parameters Explained

RESP Parameters

Response codes returned by the command:

  • RESP: Primary response code - indicates the success or failure of the update operation
  • RESP2: Secondary response code - provides additional error information when RESP indicates failure
  • Always check these codes for command success before proceeding with data processing
  • Handle command failures appropriately to prevent application errors

Update Types

1. Basic Updates

  • Basic updates: Standard update operations that handle simple data modification without special formatting
  • Mapped updates: Update operations that use predefined field mappings to structure update data
  • Unmapped updates: Raw update operations that handle unstructured data modification without predefined field mappings
  • Custom updates: Specialized update operations designed for specific application requirements

2. Advanced Updates

  • Advanced updates: Complex update operations that handle sophisticated data processing and validation
  • Secure updates: Update operations that include encryption and security features for sensitive data
  • Encrypted updates: Update operations that automatically encrypt update data
  • Compressed updates: Update operations that handle compressed data streams and automatically compress update data

3. Specialized Updates

  • Specialized updates: Update operations tailored for specific protocols or communication methods
  • High-performance updates: Optimized update operations designed for maximum throughput and efficiency
  • Low-latency updates: Update operations optimized for minimal delay and real-time processing requirements
  • High-throughput updates: Update operations designed to handle large volumes of data efficiently

Implementation Example

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WORKING-STORAGE SECTION.
01 WS-RESPONSE            PIC S9(8) COMP.
01 WS-RESPONSE2           PIC S9(8) COMP.
 
PROCEDURE DIVISION.
    * Issue update
    EXEC CICS ISSUE UPDATE
        RESP(WS-RESPONSE)
        RESP2(WS-RESPONSE2)
    END-EXEC.
    
    IF WS-RESPONSE NOT EQUAL DFHRESP(NORMAL)
        EXEC CICS WRITE OPERATOR
            TEXT('ISSUE UPDATE command failed')
        END-EXEC
        EXEC CICS RETURN END-EXEC
    END-IF.
    
    * Update issued successfully
    * Continue processing

Update Processing

1. Update Preparation

Update preparation includes:

  • Update validation - ensuring the update operation is properly configured and authorized
  • Update formatting - preparing data structures and buffers for update data
  • Update encoding - setting up proper character encoding and data transformation
  • Update processing - initializing the update operation and preparing for data modification

2. Update Transmission

Update transmission includes:

  • Update routing - directing update data to the appropriate processing location
  • Update delivery - ensuring update data reaches the correct destination within the application
  • Transmission confirmation - verifying that update was completed successfully
  • Error handling - managing transmission failures and implementing retry mechanisms

3. Output Management

Output management includes:

  • User management - handling user sessions and maintaining connection state
  • Output formatting - structuring update data for presentation or further processing
  • User experience - ensuring smooth data flow and responsive application behavior
  • Performance optimization - maximizing update efficiency and minimizing resource usage

Common Response Codes

Success Response Codes

  • NORMAL (0): Update issued successfully - data was updated without errors
  • UPDATE (4): Update issued - operation completed with update-specific status

Error Response Codes

  • INVREQ (16): Invalid request - the update operation parameters are incorrect or unauthorized
  • NOTFND (20): Resource not found - the specified update resource does not exist
  • LENGERR (22): Length error - the update data length exceeds expected limits
  • UPDATE (24): Update error - an update-specific error occurred during the operation

Best Practices

1. Update Preparation

  • Prepare update appropriately - ensure all necessary resources and configurations are in place
  • Validate update content - verify that update data meets expected format and quality standards
  • Handle different update types - implement flexible processing to accommodate various data formats
  • Ensure update integrity - maintain data consistency and prevent corruption during modification

2. Error Handling

  • Check all response codes - always examine both RESP and RESP2 for complete error information
  • Handle update failures - implement appropriate recovery mechanisms for failed update operations
  • Implement retry logic - provide automatic retry capabilities for transient failures
  • Log error conditions - maintain detailed logs for troubleshooting and monitoring purposes

3. Performance Optimization

  • Minimize update operations - reduce unnecessary update calls to improve overall performance
  • Use efficient update formats - choose appropriate data formats to minimize processing overhead
  • Optimize user updates - streamline user interface updates to reduce response time
  • Manage user resources - efficiently allocate and manage system resources for update operations

Explain It Like I'm 5 Years Old

Imagine you're updating your drawing:

When you want to update your drawing, you erase some parts and draw new parts. If the update works, your drawing looks better. If the update doesn't work, you have to try again.

CICS ISSUE UPDATE is like updating your drawing. The computer program erases some data and puts in new data. If the update works, the data looks better. If the update doesn't work, the program has to try again.

Just like you update drawings, the computer program updates data!

Exercises

Exercise 1: Update Issuance

Write a CICS ISSUE UPDATE command to issue an update operation.

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EXEC CICS ISSUE UPDATE
    RESP(WS-RESPONSE)
    RESP2(WS-RESPONSE2)
END-EXEC.

Exercise 2: Update Processing

How would you implement comprehensive update processing that handles different update types and requirements?

Answer: Identify different update types and appropriate handling, implement update validation and encoding, handle different update types and capabilities, implement proper error handling for update failures, optimize update operations for performance, and maintain update integrity throughout the process.

Quiz

Question 1

What is the primary purpose of CICS ISSUE UPDATE?

Answer: B) To issue an update operation

Question 2

Which parameter specifies the response code?

Answer: A) RESP

Related Concepts

CICS Update Processing

Update processing and output in CICS

CICS User Management

User management and user interaction in CICS

CICS Output Processing

Output processing and update display in CICS