PQ82008: Dynamic Cache HTOP performance improvement fix

 Fixes are available

5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for AIX
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for HP-UX
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for Linux
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for AIX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for AIX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for HP-UX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Solaris
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Windows
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Linux
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Linux
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Solaris
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Windows
5.0.2.7: WebSphere Application Server Express 5.0.2 Cumulative Fix 7
5.1.0.5: WebSphere Application Server V5.1.0 Cumulative Fix 5
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Solaris
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Windows
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Solaris
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Windows
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for AIX
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Linux
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for AIX
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for Windows
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Solaris
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Windows
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Solaris
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for AIX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for AIX
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Linux
5.0.2.12: WebSphere Application Server 5.0.2 Cumulative Fix 12
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for HP-UX
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for AIX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Windows
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for HP-UX
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for AIX
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for AIX
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Linux
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for HP-UX
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Linux
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for HP-UX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Linux
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for HP-UX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Windows
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Solaris
5.0.2.8: WebSphere Application Server V5.0.2 Cumulative Fix 8
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Windows
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for AIX
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Windows
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Solaris
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Solaris
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Linux
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Windows
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for HP-UX
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for AIX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Windows
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Solaris
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Windows
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for AIX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Linux
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for HP-UX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Solaris
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for AIX
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Windows
5.0.2.13: WebSphere Application Server 5.0.2 Cumulative Fix 13
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for HP-UX
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Linux
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for AIX
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Linux
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Windows
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Windows
5.0.2.5: WebSphere Application Server 5.0.2 Cumulative Fix 5
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Linux
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for HP-UX
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for HP-UX
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for HP-UX
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Linux
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Solaris
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for AIX
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for HP-UX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for HP-UX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Linux
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Linux
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for HP-UX



APAR status
Closed as program error.

Error description
WCS requested a fix to improve the performance of the offload to
disk function of dynamic cache.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: WebSphere Application Server dynacache       *
*                 users using disk cache                       *
****************************************************************
* PROBLEM DESCRIPTION: Improve Dynacache's disk cache          *
*                      performance                             *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
An IBM internal team did some Dynacache performance
measurment - Disk cache vs Memory. The result shows the
performance of disk cache running unexpectedly slow.
Problem conclusion
The following solutions improve the disk cache performance:
Use memory auxiliary Dep Id table and Template table for
subset of entries in disk.
Don't delete disk entry while promoting to memory.  LRU on
these entries again will not write data to disk unless it has
been modified.
Reduce code path and other minor changes.

There was about 5X improvement when testing.
The other IBM internal team also had good success using the fix
in a more realistic load scenario.
Temporary fix Comments
APAR information
APAR number PQ82008
Reported component name WAS BASE 5.0
Reported component ID 5630A3600
Reported release 00W
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2003-12-10
Closed date 2004-01-30
Last modified date 2004-01-30

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
dynacach          

Publications Referenced

Fix information

Applicable component levels
R003 PSY    UP
R00A PSY    UP
R00H PSY    UP
R00I PSY    UP
R00P PSY    UP
R00S PSY    UP
R00W PSY    UP
R103 PSY    UP
R10A PSY    UP
R10H PSY    UP
R10I PSY    UP
R10P PSY    UP
R10S PSY    UP
R10W PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 00W
Software edition:
Reference #: PQ82008
IBM Group: Software Group
Modified date: Jan 30, 2004