The vIP cluster resource does not follow the SAP HANA master instance
This document (000019769) is provided subject to the disclaimer at the end of this document.
Environment
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server 12
Situation
On a HANA Scale-up cluster, when the HANA Master instance failover to the other node, the vIP doesn't follows it.
Considering the following scenario on which the vIP is part of group with two members, the vIP resources group (grp-vips_DB02) should follow the HANA Master instance:
However this doesn't happen, as the colocation score should be larger than the total sum of resources score of vIP group, this can be noticed on the pacemaker logs of the DC node, where the vIP resources are not moving to the other node (hana2-host):
On the above cluster configuration (resource-stickiness=1000) every resource has a resource stickiness of 1000, thus the group grp-vips_DB02 has a total resource stickiness of 2000, as the resource stickiness of a group is the sum of its members, which is not lower than the colocation score of 2000, that would cause the grp-vips_DB02 group to stay on the current node, rather than following the HANA Master instance. In this case the local resource stickiness wins over the colocation score.
Considering the following scenario on which the vIP is part of group with two members, the vIP resources group (grp-vips_DB02) should follow the HANA Master instance:
primitive vip_DB02_a IPaddr2 \ params ip=10.101.12.101 \ op monitor interval=10s timeout=20s primitive vip_DB02_b IPaddr2 \ params ip=10.101.12.102 \ op monitor interval=10s timeout=20s group grp-vips_DB02 vip_DB02_a vip_DB02_b ms ms_SAPHana_DB02_HDB00 SAPHana_DB02_HDB00 \ meta clone-max=2 clone-node-max=1 interleave=true colocation col-SAPHana_DB02_HDB00 2000: grp-vips_DB02:Started ms_SAPHana_DB02_HDB00:Master ... rsc_defaults rsc-options: \ resource-stickiness=1000
However this doesn't happen, as the colocation score should be larger than the total sum of resources score of vIP group, this can be noticed on the pacemaker logs of the DC node, where the vIP resources are not moving to the other node (hana2-host):
hana2-host pengine: info: native_choose_node: Chose node hana01-host for vip_DB02_a from 2 nodes with score 2000
On the above cluster configuration (resource-stickiness=1000) every resource has a resource stickiness of 1000, thus the group grp-vips_DB02 has a total resource stickiness of 2000, as the resource stickiness of a group is the sum of its members, which is not lower than the colocation score of 2000, that would cause the grp-vips_DB02 group to stay on the current node, rather than following the HANA Master instance. In this case the local resource stickiness wins over the colocation score.
Resolution
This issue can be overcome by increasing the colocation score to be larger than the grp-vips_DB02 group score:
colocation col-SAPHana_DB02_HDB00 4000: grp-vips_DB02:Started ms_SAPHana_DB02_HDB00:Master
Cause
This issue is caused by using an insufficient colocation score, which is not enough to win over the local stickiness of a resource group.
Disclaimer
This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.
- Document ID:000019769
- Creation Date: 30-Oct-2020
- Modified Date:31-Oct-2020
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- SUSE Linux Enterprise High Availability Extension
- SUSE Linux Enterprise Server
- SUSE Linux Enterprise Server for SAP Applications
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