MFE SRDF-HC: Host Component batch Interface commands issued out of order

Commands that are issued through the batch interface can be assigned to a command queue (CQNAME). The use of a CQNAME ensures that mutually dependent commands are issued one at a time, in the order in which they were entered.        

Due to a timing issue, the CQNAME was not honored and commands had the potential to be issued out of order.       

The documentation states the following within the SRDF Host Component for z/OS Product Guide, section "Command processing by queue name":

"To ensure that mutually dependent commands are processed one at a time in the order in which you enter them, SRDF Host Component allows you to place most commands on designated named command queues.

Commands on the same queue are processed in the order in which they were placed on the queue, while commands on different queues are processed independently of each other. As a result of this, commands on different queues may be processed concurrently, and a command on a queue could even be processed ahead of another command that was entered earlier but placed on a different queue.

SRDF Host Component individually moves commands queued on the same named command queue to the appropriate subtask queue.

There is no inherent relationship between named command queues and subtask queues. Thus, different commands on the same named command queue may be placed on the subtask queues for different storage systems, or on the global task queue. However, the commands are always scheduled in the order in which they appeared on the named command queue. A command on a named command queue is never scheduled until the command that preceded it on the named command queue completes processing."

However, Host Component performs commands on the same named queue out of order. As a result, mutually dependent commands may fail.

This occurs when the user submits a mix of different kinds of commands to be run by:

• Two concurrent z/OS tasks are supported for each storage system, one dedicated to query (SQ) commands and one dedicated to configuration (SC) commands;
• SRDF Host Component global task or main task is dedicated to running commands not specific to a single storage system.

This is due to a software issue.

Processing was modified to correctly handle the timing issue to ensure the CQNAME order of commands is honored.   
  
Permanent Fix:

• For Mainframe Enablers 8.5, PTF SR85026 has been developed to correct the issue. It is available to download from Dell Online Support
• For Mainframe Enablers 8.4, PTF SR84042 has been developed to correct the issue. It is available to download from Dell Online Support

PTF Cover Note:
 

++PTF(SR85026) REWORK(2022039) .                               
++VER(Z038) FMID(SRDF850)                                      
      PRE(                                                     
          SR85017                                              
          )                                                     
   /*                                                          
*------------------------------------------------------------- 
* PROBLEM DESCRIPTION(S):                                      
* ------------------------------------------------------------ 
* USERS AFFECTED: Host Component Batch Interface               
* PROBLEM DESCRIPTION: Commands issued out of order            
* DESCRIPTION DETAIL:                                           
*                                                              
* Commands that are issued through the batch interface can be assigned  
* to a command queue (CQNAME). The use of a CQNAME ensures     
* that mutually dependent commands are issued one at a time,   
* in the order in which they were entered.                     
*                                                              
* Due to a timing issue, the CQNAME was not honored and        
* commands had the potential to be issued out of order.        
*                                                              
* PROBLEM RESOLUTION:                                          
*                                                              
* Processing was modified to correctly handle the timing       
* issue to ensure the CQNAME order of commands is honoured.     
*                                                               
*                                                              
* MODULES: EMCSTC                                              
*                                                              
* ------------------------------------------------------------ 
* SR85026 8 Feb 2022 12:15:49                                  
* ------------------------------------------------------------