PM01819: INCREASE IN E/CSA AND E/SQA USAGE WHEN RUNNING MANY CONCURRENT DATA RECOVER OPERATIONS IN DATA SHARING MODE.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• An increase in E/CSA and E/SQA usage may be seen when running
  many concurrent data recovery operations (ie. RECOVER or OLR
  utilities, -START DATABASE for GRECP/LPL recovery) as DB2 does
  not correctly limit the number of active log prefetch SRBs in
  data sharing mode.  If hundreds of these SRBs are active, it
  could result in an ABEND878 or ABEND04E RC00E2001F due to a
  shortage of E/CSA or E/SQA storage.
  JR06A system threads
  DB2STGLK/K
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All data sharing users of DB2.               *
  ****************************************************************
  * PROBLEM DESCRIPTION: DB2 does not correctly limit the        *
  *                      number of active log read prefetch      *
  *                      SRBs when running in data sharing       *
  *                      mode.  This can lead to an increase in  *
  *                      E/CSA and E/SQA usage when running      *
  *                      many concurrent recovery operations.    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  In data sharing mode, DB2 does not limit the number of
  active log prefetch SRBs correctly.  When running many
  concurrent recovery operations (ie. RECOVER or OLR utilities,
  or -START DATABASE commands for GRECP/LPL recovery), this
  can lead to an increase in E/CSA and E/SQA storage usage.
  

Problem conclusion

• DSNJR006 has been changed so that active log read prefetch
  SRBs will only be allocated when there are not more than 100
  open log-read cursors.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UK52393 UK52394

Modules/Macros

• DSNJR006
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R810 PSY UK52393

     UP09/12/15 P F912

• R910 PSY UK52394

     UP09/12/15 P F912

Fix is available

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