A fix is available
APAR status
Closed as program error.
Error description
************************************************************** * USERS AFFECTED: * Systems running the AIX 7200-01 Technology Level * with bos.cluster.rte at the 7.2.1.0 or 7.2.1.1 level. ************************************************************** * ERROR DESCRIPTION: * After rebooting a node in either a PowerHA or VIOS SSP cluster * using CAA, there is a chance that the node may create its own * cluster, causing a split-brain / partitioned cluster in the * CAA environment. * * This is more likely to be seen if the network is slow and * there is a delay in gossip packets being received by the * rebooted node. * * The effect of a split-brain / partitioned cluster can vary, * but in the worst cases: PowerHA may react by bringing * resources online at the same time on multiple nodes, and * VIOS SSP can experience pool going down on one or more nodes. ************************************************************** * RECOMMENDATION: * Install APAR IV97266. * Prior to fix availability, an interim fix is available from * either * ftp://aix.software.ibm.com/aix/ifixes/iv97266/ * https://aix.software.ibm.com/aix/ifixes/iv97266/ * The ifix can be installed using Live Update (LU). * If LU is not used, installation of the ifix requires a * reboot. **************************************************************
Local fix
n/a
Problem summary
PROBLEM SUMMARY: After rebooting a node in either a PowerHA or VIOS SSP cluster using CAA, there is a chance that the node may create its own cluster, causing a split-brain / partitioned cluster in the CAA environment. This is more likely to be seen if the network is slow and there is a delay in gossip packets being received by the rebooted node. The effect of a split-brain / partitioned cluster can vary, but in the worst cases: PowerHA may react by bringing resources online at the same time on multiple nodes, and VIOS SSP can experience pool going down on one or more nodes.
Problem conclusion
There is a gate in which all initial clusterwide lock requests should consider the count of nodes heartbeating to the repository in addition to those gossiping over network. There was a hole in the gate and the fix closes it.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
IV97266
Reported component name
AIX V7.2
Reported component ID
5765CD200
Reported release
720
Status
CLOSED PER
PE
YesPE
HIPER
YesHIPER
Submitted date
2017-06-16
Closed date
2017-06-16
Last modified date
2017-11-07
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
AIX V7.2
Fixed component ID
5765CD200
Applicable component levels
R720 PSY U873440
UP17/09/21 I 1000
PTF to Fileset Mapping
U873440 bos.cluster.rte 7.2.1.2
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Document Information
Modified date:
07 November 2017