APAR status
Closed as program error.
Error description
ibmlb2 crashes. On Linux and Windows, server.log contains com.ibm.ws.loadbalancer.stack.LBStackException reports with 'Communication with executor failed' message.
Local fix
Use iptables to block icmp6 traffic which should keep it from crashing.
Problem summary
**************************************************************** * USERS AFFECTED: IBM WebSphere Application Server Load * * Balancer for IPv4 and IPv6 * **************************************************************** * PROBLEM DESCRIPTION: The ibmlb2 process may crash in * * function os_xmitraw6 when using IPv6 * * clusters. * **************************************************************** * RECOMMENDATION: * **************************************************************** The crash call stack shows os_xmitraw6 as the last LB function; lbsel_send and an lbicmpv6 function occur previously on the stack. The crash will not occur if only IPv4 clusters are defined.
Problem conclusion
When the load balancer is sending an icmpv6 packet, a function was called with incorrect parameters which caused the crash. The code was modified to invoke the function with correct parameters. Fix levels: 8.5.5.20 9.0.5.8
Temporary fix
Comments
APAR Information
APAR number
PH34372
Reported component name
WS EDGE LB IPV4
Reported component ID
5724H8812
Reported release
900
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2021-02-10
Closed date
2021-03-10
Last modified date
2021-03-10
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":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"900"}]
Document Information
Modified date:
11 March 2021