PQ91814: HangDetection threshold adjustment algorithm fails to adjust when initial threshold value is set to 1.

 Fixes are available

5.1.1.8: WebSphere Application Server 5.1.1 Cumulative Fix 8 for AIX
5.1.1.8: WebSphere Application Server 5.1.1 Cumulative Fix 8 for Windows
5.1.1.8: WebSphere Application Server 5.1.1 Cumulative Fix 8 for HP-UX
5.1.1.8: WebSphere Application Server 5.1.1 Cumulative Fix 8 for Solaris
5.1.1.6: WebSphere Application Server Version 5.1.1 Cumulative Fix 6
5.1.1.7: WebSphere Application Server Version 5.1.1 Cumulative Fix 7
5.1.1.4: WebSphere Application Server Version 5.1.1 Cumulative Fix 4
5.1.1.1: WebSphere Application Server Express 5.1.1 Cumulative Fix 1
5.1.1.8: WebSphere Application Server 5.1.1 Cumulative Fix 8 for Linux
5.1.1.1: WebSphere Application Server Version 5.1.1 Cumulative Fix 1



APAR status
Closed as program error.

Error description
Per the online documentation, if you set the false alarm
threshold to a certain value (1 in this case) and the false
alarm threshold value has  been reached, the detect hang
policy should adjust the thread.monitor threshold  by a value of
(threadmonitor.threshold value) x 1.5 = new
threadmonitor.threshold value.

I am finding this to be the case when my initial threshold
value is greater than 1, however, if the value is equal to 1,
the threshold value never  gets increased to a value greater
than 1 when it is reset.
Example:

ThreadMonitor W WSVR0607W: Too many thread hangs have been
falsely reported.  The hang threshold is now being set to 1
seconds The above example shows that the hang threshold is
being set  to 1 even though it was already set to 1 initially.
1 x 1.5 = 1
Local fix Problem summary
****************************************************************
* USERS AFFECTED: Potentially all users are affected           *
****************************************************************
* PROBLEM DESCRIPTION: When using the HangDetection            *
*                      capabilites of the appserver with       *
*                      extremely low time values (1 second),   *
*                      the threshold will not adjust up as     *
*                      documented.                             *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
Due to the way integer math works, when calculating the new
HangDetection threashold, truncation results in an inability to
adjust the threashold upwards when the value is initially set
to 1 second (this would be a very unusual setting and
pratically not be used).
Problem conclusion
The HangDetection threshold adjustment algortithm now
incorporates a rounding algorithm that allows the adjustment
calculation to round up the answer, thereby preventing the
adjusted threashold from being effectively stuck at 1 (in
effect 1 + .5 = 2). This is essentially protecting this
algorithm under all boundry conditions.
Temporary fix Comments
APAR information
APAR number PQ91814
Reported component name WAS BASE 5.0
Reported component ID 5630A3600
Reported release 10W
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2004-07-22
Closed date 2004-08-10
Last modified date 2004-08-10

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
RUNTIME          

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: 10W
Software edition:
Reference #: PQ91814
IBM Group: Software Group
Modified date: Aug 10, 2004