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CICS POST - Post

CICS POST provides post management capabilities, enabling post processing and output processing in CICS environments. It provides efficient post capabilities for CICS applications.

What is CICS POST?

CICS POST provides post management capabilities, enabling post processing and output processing. It provides efficient post capabilities, allowing applications to manage post operations.

Command Syntax

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EXEC CICS POST
    [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 post 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

Post Types

1. Basic Posts

  • Basic posts: Standard post operations that handle simple posting without special formatting
  • Mapped posts: Post operations that use predefined field mappings to structure post data
  • Unmapped posts: Raw post operations that handle unstructured posting without predefined field mappings
  • Custom posts: Specialized post operations designed for specific application requirements

2. Advanced Posts

  • Advanced posts: Complex post operations that handle sophisticated posting processing and validation
  • Secure posts: Post operations that include encryption and security features for sensitive posting
  • Encrypted posts: Post operations that automatically encrypt post data
  • Compressed posts: Post operations that handle compressed posting streams and automatically compress post data

3. Specialized Posts

  • Specialized posts: Post operations tailored for specific protocols or communication methods
  • High-performance posts: Optimized post operations designed for maximum throughput and efficiency
  • Low-latency posts: Post operations optimized for minimal delay and real-time processing requirements
  • High-throughput posts: Post operations designed to handle large volumes of posting 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.
    * Post operation
    EXEC CICS POST
        RESP(WS-RESPONSE)
        RESP2(WS-RESPONSE2)
    END-EXEC.
    
    IF WS-RESPONSE NOT EQUAL DFHRESP(NORMAL)
        EXEC CICS WRITE OPERATOR
            TEXT('POST command failed')
        END-EXEC
        EXEC CICS RETURN END-EXEC
    END-IF.
    
    * Post operation completed successfully
    * Continue processing

Post Processing

1. Post Preparation

Post preparation includes:

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

2. Post Transmission

Post transmission includes:

  • Post routing - directing post data to the appropriate processing location
  • Post delivery - ensuring post data reaches the correct destination within the application
  • Transmission confirmation - verifying that post 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 post data for presentation or further processing
  • User experience - ensuring smooth data flow and responsive application behavior
  • Performance optimization - maximizing post efficiency and minimizing resource usage

Common Response Codes

Success Response Codes

  • NORMAL (0): Post operation completed successfully - posting was completed without errors
  • POST (4): Post operation completed - operation completed with post-specific status

Error Response Codes

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

Best Practices

1. Post Preparation

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

2. Error Handling

  • Check all response codes - always examine both RESP and RESP2 for complete error information
  • Handle post failures - implement appropriate recovery mechanisms for failed post 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 post operations - reduce unnecessary post calls to improve overall performance
  • Use efficient post 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 post operations

Explain It Like I'm 5 Years Old

Imagine you're putting a letter in a mailbox:

When you want to send a letter, you write it and put it in a mailbox. If you put the letter in the mailbox, the mailman takes it and delivers it. If you don't put the letter in the mailbox, the mailman doesn't take it and doesn't deliver it.

CICS POST is like putting a letter in a mailbox. The computer program writes a message and puts it in a special mailbox. If it puts the message in the mailbox, the other computer gets it. If it doesn't put the message in the mailbox, the other computer doesn't get it.

Just like you put letters in mailboxes, the computer program puts messages in special mailboxes!

Exercises

Exercise 1: Post Operation

Write a CICS POST command to perform a post operation.

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

Exercise 2: Post Processing

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

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

Quiz

Question 1

What is the primary purpose of CICS POST?

Answer: B) To provide post management capabilities

Question 2

Which parameter specifies the response code?

Answer: A) RESP

Related Concepts

CICS Post Processing

Post processing and output in CICS

CICS User Management

User management and user interaction in CICS

CICS Output Processing

Output processing and post display in CICS