In TPX user exit TPXUGACB, what is the maximum value to specify for NUMENTRY, the number of table entries in the ACB assignment table?

Products

• TPX - Session Management
• Vman Session Management for z/OS

Issue/Introduction

Issue: 

 

The production system is using the TPXUGACB exit with NYMNTRY=3000.  If the system is up for more than about 50 days, the incore table is full and we start having abends:

TPXUGACB - INCORE SAVED ACB TABLE FULL 

DUMP TITLE=TPX990E ABEND S0C1 - MODULE=TPXUGACB, TASK=EXITTASK 

 

Recycling TPX resolves this.  

I tried to increase the table, first to 4000 and then to 3500, using the test system.   When I start TPX in test using these higher values, it will not come up.  It fails with U0031: 

IEA995I SYMPTOM DUMP OUTPUT  184                                  

  USER COMPLETION CODE=0031                                       

 TIME=13.41.49  SEQ=00230  CPU=0000  ASID=0021                    

 PSW AT TIME OF ERROR  070C1000   8003A52C  ILC 2  INTC 0D        

   ACTIVE LOAD MODULE           ADDRESS=0003A3E0  OFFSET=0000014C 

   NAME=TPXGTSTR                                                  

   DATA AT PSW  0003A526 - 00181610  0A0D9104  049F47E0           

   AR/GR 0: 00000000/80000000   1: 00000004/8000001F              

         2: 00000000/00019000   3: 00000000/00000000              

         4: 00000000/00000000   5: 00000000/21764000              

         6: 00000000/008D6FC8   7: 00000000/00000000              

         8: 00000000/80000000   9: 00000000/00000000              

         A: 00000000/80010712   B: 00000000/00022038              

         C: 00000000/0003A420   D: 00000000/006B8F48              

         E: 00000000/80030870   F: 00000000/006B8EB8              

 END OF SYMPTOM DUMP                                              

 

In TPX user exit TPXUGACB, what is the maximum value to specify for NUMENTRY, the number of table entries in the ACB assignment table?

 

Cause: 

From the delivered TPXUGACB SRC:

 

GETSTOR BYTES=AATLEN


...

AATENT   DSECT                                              

AATUID   DS    CL8                                          

AATSID   DS    CL8                                          

AATAPID  DS    CL8                                          

AATACB   DS    CL8                                          

AATENT#  EQU   *-AATENT             LENGTH OF SINGLE ENTRY  

NUMENTRY EQU   500                  NUMBER OF TABLE ENTRIES 

AATLEN   EQU   AATENT#*NUMENTRY     TABLE SIZE              

 

 

So each of the 4 fields in AATENT (ACB assignment table) has a character length of 8 bytes for a total of 32 bytes.

 

AATLEN = 32 * NUMENTRY

 

32 x 4000 = 128000 bytes 

32 x 3500 = 112000 bytes 

 

The problem with these values is that TPXUGACB exit is doing a GETSTOR call for 128000 bytes of storage.

 

The U031 abend occurs because the maximum request allowed by z/OS is for 100,000 bytes.

 

 

Resolution:

The maximum value that should work for NUMENTRY is 100,000/32 = 3125. 

If you find that 3125 is not sufficient then you need to identify why you are using this exit.

 

Additional Information:

TPX 5.4 documentation: ACB Selection Exit

 

Environment

Release: NVINAM00200-5.3-TPX-Session Management-Access Management package
Component: