PM99468: EZASMI SELECT CALLS USE MORE ECSA AFTER Z/OS 2.1 UPGRADE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After upgrading to z/OS 2.1, each SELECT socket call issued
  using the Macro Extended Sockets API (which includes use of the
  EZASMI macro, EZASOKET calls, CICS Sockets API, and IMS Sockets
  API) will cause allocation of a 25K (x'6400') byte area of
  SP241K6 ECSA storage that was not used on earlier releases.  On
  systems have a large number of applications (or instances of an
  application) that use this function, it can have a significant
  impact on overall ECSA usage.
  
  
  Symptoms:
  
     EZD1170E TCPIP WAS NOT ABLE TO GET TCP/IP ECSA STORAGE
     messages.
  
     ENOMEM errors returned on socket calls.
  
     S4C5/xxxx2500 or xxxx2508 ABENDs
  
     A VSMDATA SUMMARY report run from a dump will show multiple
     instances of x'7000' byte areas of SP241K6 storage with
     x'C00' bytes unused at the beginning.
  
     A VSMDATA OWNCOMM report run from a dump will show these
     areas being allocated from EZBITDSA+000504 (in the EZBTIINI
     module).
  
     A TCPIPCS DUAF report run from a dump will show multiple in
     use DUCBs with a pattern similar to the following:
  
        10000803 322DB838 307A0400 307A05C8 00ED3E80 045D jjjjjjjj
        RSA  307A0BB8  Prev 3A6CE028  Next 307A0C90  Mod EZBSOMPC
        RSA  307A0C98  Prev 307A0BB8  Next 307A15B8  Mod EZBSOMIF
        RSA  307A15C0  Prev 307A0C98  Next 28F20C38  Mod EZBSOMIS
        RSA at 28F20C40 is outside address range of DUSA
        RSA  28F20C40  Prev 307A15C0  Next 28F21100  Mod EZBSOMSE
         6416 bytes were used
  

Local fix

• Increase ECSA allocation or reduce system workload if storage
  shortage conditions are occurring.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of IBM Communications Server                       *
  * for z/OS Version 2 Release 1 IP: EZASMI                      *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ECSA storage increase when using the EZASMI Macro Socket API *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply PTF                                                    *
  ****************************************************************
  The savearea increase in EZBSOMIF and EZBSOMSE caused DUSA
  expansions too occur for mini DUCBs.
  

Problem conclusion

• The mini DUCB size will be increased from 7K to 8K to avoid DUSA
  expansions.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UI11752

Modules/Macros

• EZBITDSA EZBITDCR
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R210 PSY UI11752

     UP13/12/06 P F312

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.