|
Problem IC97731
|
Status: Closed |
AUTHENTICATION VERY SLOW ON CERTAIN PSERIES HARDWARE WITH POWER5+ CPU'S |
| product: |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 |
| Problem description: |
OS Authentication for DB2 can be very slow in AIX or pSeries
Linux on certain pSeries hardware with POWER5+ CPUs. The
function cryptContextRealInit which makes ICC (IBM Cryptographic
library for C) API calls.
The problem exists on the following environments:
- Certain models of pSeries POWER5+ CPUs (AIX and Linux)
or
- Virtualized environments (LPARs) (not restricted to any
specific CPU)
This issue is due to the design of the getbyte() function in the
ICC library (libicclib.so), which gets a byte of random data
using the jitter from values obtained against the Timebase
register (TBR). Due to changes to the clock source in the
POWER5+ architecture, and similar behavior in VMWare
environments, this results in excessive computation in the
getbyte() function. The command
tprof -skeuj -x sleep 5
can be used to confirm whether the the library libicclib.so is
using an excessive percentage of CPU.
The affected version of ICC is 1.4.x (1.4.1) which shipped in
DB2 UDB (distributed) from 8.2.5 (Fixpak 11) and above. This
problem exists in all current versions of DB2. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All DB2 systems on all Linux, Unix and Windows platforms at *
* service levels Version 10.5 GA through to Version 10.5 Fix *
* Pack 3. *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 10.1 Fix Pack 3a or see "Local Fix" *
* portion for other suggestions. *
**************************************************************** |
| Local Fix: |
For AIX on PowerPC, see the technote:
"DB2 Performance Issue Related to Cryptography on Power Series
Hardware"
http://www.ibm.com/support/docview.wss?uid=swg21614548
Otherwise, there is no local fix. Please contact DB2 Technical
Support for a special build
if you are on an affected environment. |
| available fix packs: |
DB2 Cancun Release 10.5.0.4 (also known as Fix Pack 4) for Linux, UNIX, and Windows
DB2 Version 10.5 Fix Pack 9 for Linux, UNIX, and Windows
|
| Solution |
The complete fix for this problem first appears in DB2 Version
10.1 Fix Pack 3a and all the subsequent Fix Packs. |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 18.11.2013
03.06.2014
03.06.2014 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 10.5.0.4
|
 |
