DB2 FOR LUW / DB2FORLUW / A50 - DB2

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.

**************************************************************** 
* 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.                               * 
****************************************************************

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.

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
 

The complete fix for this problem first appears in DB2 Version 
10.1 Fix Pack 3a and all the subsequent Fix Packs.

keiner bekannt / siehe Local-Fix

Datum - Problem gemeldet    :
Datum - Problem geschlossen :
Datum - der letzten Änderung:

18.11.2013
03.06.2014
03.06.2014