IZ25612: SET WRITE SUSPEND ON A BUSY DATABASE CAN HANG FOR A VERY LONG TIME, WAITING ON THE PAGECLEANERS GETTING PAUSED

APAR status

• Closed as program error.

Error description

• The SET WRITE SUSPEND session is waiting in the following stack:
  
  (6)  0xc00000000032f310  _semtimedop_sys + 0x30
  [/usr/lib/hpux64/libc.so.1]
  (7)  0xc00000000033d870  _semtimedop + 0xb0
  [/usr/lib/hpux64/libc.so.1]
  (8)  0xc00000000915ce10  sqloWaitEDUWaitPost + 0x350
  [/opt/IBM/db2/V8.1/lib64/libdb2e.so]
  (9)  0xc00000000a125170  _Z21sqlbPauseCleanerGroupP20SQ + 0x5f0
  [/opt/IBM/db2/V8.1/lib64/libdb2e.so]
  (10) 0xc00000000a125e50  _Z20sqlbPauseAllCleanersP12SQLB + 0x170
  [/opt/IBM/db2/V8.1/lib64/libdb2e.so]
  (11) 0xc00000000a1f6ae0  _Z16sqlbSuspendWritetP12SQLB_GLOBALS +
  0x350  [/opt/IBM/db2/V8.1/lib64/libdb2e.so]
  (12) 0xc00000000a1fc990  _Z17sqlbSetPoolChangeP5sqldaS0_P5sqlca
  + 0x1150  [/opt/IBM/db2/V8.1/lib64/libdb2e.so]
  ...
  
  There is a bigger chance to run into this issue on platforms,
  where LIO is not implemented, like HP.
  
  This APAR adds some timeout code to pagecleaners, so that the
  pausing of pagecleaners finish in a timely manner.
  

Local fix

• Do not run SET WRITE SUSPEND, while there is load on the
  database.
  

Problem summary

• USERS AFFECTED
  All
  
  PROBLEM SUMMARY
  See ERROR DESCRIPTION
  

Problem conclusion

• First fixed in DB2 UDB Version 8.1, FixPak 18
  

Temporary fix

• See LOCAL FIX.
  

Comments

APAR Information

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

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

  IZ25687 IZ25688

Fix information

• Fixed component name

  DB2 UDB ESE HP-

• Fixed component ID

  5765F4103

Applicable component levels

• R810 PSN

     UP

• R820 PSN

     UP

• R910 PSN

     UP

• R950 PSN

     UP