APAR status
Closed as program error.
Error description
Events reported in log files: Windows event log: Error 1000 (100) "Faulting application name: ibmlb2.exe, version: 0.0.0.0, time stamp: 0x61f81e6e Exception code: 0xc0000374 Faulting application path: C:\Program Files\IBM\WebSphere\Edge\ULB\servers\bin\ibmlb2.exe LB ibmlb2.log: Warning: [os_pullup] should not have been reached on Windows
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: IBM WebSphere Network Deployment Load * * Balancer for IPv4 and IPv6 users on * * Windows operating systems * **************************************************************** * PROBLEM DESCRIPTION: The LB server.log indicates * * "Communication with executor failed"; * * packets not forwarded, LB commands * * fail. * **************************************************************** * RECOMMENDATION: * **************************************************************** The executor module (ibmlb2) crashes. The Windows event log reports exception code 0xc0000374 with faulting application ibmlb2.exe. LB's ibmlb2.log contains the message "Warning: [os_pullup] should not have been reached on Windows". Packets not forwarded and LB commands fail after this issue occurs. Crash call stack contains ibmlb2 contains: os_memfree DEBUG_OS_MEMFREE lbfrag_pbuf_firstfragment lbsel_send lbtcpudp_pbuf_entry
Problem conclusion
The problem occurs when LB has received fragmented packets for a cluster. The first fragment (which contains TCP headers necessary to select a server) arrived after other fragments. Previous fragments are stored, waiting for the first fragment to be process. At least one of the stored fragments was smaller than 40 bytes. The Load Balancer code checks to ensure that data contains the minimal necessary number of bytes. The smaller fragment did not meet the minimal size so the memory storage was released but references remained in the stored fragment table. After the first fragment was processed and the stored fragments are sentto the server, the previously released memory was released again which causing the crash. Code was modified to prevent minimum size check on fragments other than the first fragment and Windows specific LB code modified to correct return code data check function. Fix levels: 8.5.5.22 9.0.5.13
Temporary fix
Comments
APAR Information
APAR number
PH46644
Reported component name
WS EDGE LB IPV4
Reported component ID
5724H8812
Reported release
850
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2022-05-23
Closed date
2022-05-27
Last modified date
2022-05-27
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
WS EDGE LB IPV4
Fixed component ID
5724H8812
Applicable component levels
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.5"}]
Document Information
Modified date:
28 May 2022