IZ18783: HIGH MEMORY USAGE/PAGING WITH LOCAL CONNECTIONS OR ATTACHMENTS U SING SOLARIS 10

DB2 Version 9.5 Fix Pack 3b for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 2a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 2  for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 4  for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 4a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 5 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• In DB2 9.5 on Solaris, DB2 database systems round up many of the
  shared memory segments to the largest page size supported by th
  e operating system or hardware.  Solaris 10 supports a page size
   of up to 256 MB.
  This is an issue for the small communication memory areas alloca
  ted for local connections and attachments. Each size is approxim
  ately 2 times the size of the application support layer heap (as
   defined in the ASLHEAPSZ database manager configuration paramet
  er), but will be rounded up to as much as 256MB.
  The result is that systems with even a moderate number of local
  connections/attachments will experience a dramatic increase in m
  emory requirements on DB2 9.5.
  Vulnerability to this problem can be confirmed by checking the o
  utput of pagesize -a.  The largest pagesize reported will be the
   minimum size of a communication IPC memory segment for a local
  DB2 connection or attachment.
  
  Example 1:
  # pagesize -a
  8192
  65536
  524288
  4194304
  In this case, the largest page size is 4MB, and the effect of th
  e roundup will not be severe.
  .
  Example 2:
  # pagesize -a
  8192
  65536
  524288
  4194304
  33554432
  268435456
  In this case, the maximum page size is 256MB, and the effect of
  the roundup is much more severe.  Therefore the memory wastage i
  s much higher.
  

Local fix

Problem summary

• Users Affected: DB2 systems on Solaris 10
  Problem Description: See Error description
  Problem Summary: See Error description
  

Problem conclusion

• First fixed in DB2 UDB Version 9.5, Fixpak 2
  

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:

Modules/Macros

• SQO
  

Fix information

• Fixed component name

  DB2 UDB ESE SOL

• Fixed component ID

  5765F4102

Applicable component levels