HANA nodes end up having the same LPT values

This document (000020690) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server for SAP Applications 12

Situation

Often, there are cases when cluster can not pick up on primary/ secondary roles.
Cluster tries to register the primary node as secondary, and the secondary node as primary.
The reason for it is due to manually switching roles of primary to secondary, and vice versa while cluster is in maintenance.
By that, cluster attributes get outdated, and cluster can not pick up the right roles when removed from maintenance.

Such a situation could be clearly seen using crm_mon -A1 command, where cluster nodes end up having the same LPT values, and hana_***_clone_state have values UNDEFINED, WAITING4PRIM, WAITING4REG

crm_mon -Ar command shows the below output...
# crm_mon -Ar 
...
Node List:
  * Online: [ node1 node2 ]
...
Node Attributes:
  * Node: node1:
    * hana_fu2_clone_state              : UNDEFINED 
...
    * lpa_fu2_lpt                       : 10
    * master-rsc_SAPHana_FU2_HDB02      : -9000
  * Node: node2:
    * hana_fu2_clone_state              : WAITING4PRIM
 ...
    * lpa_fu2_lpt                       : 10
    * master-rsc_SAPHana_FU2_HDB02      : -INFINITY

Resolution

Please follow the below steps to resolve the issue.
  1. Put the cluster into maintenance mode (crm maintenance on)
  2. Start HANA manually on both nodes and ensure replication is working
  3. Place the HANA master/slave resource in unmanaged mode (crm resource unmanage <resource name>)
  4. Take the cluster out of maintenance mode (crm maintenance off)
  5. Give it a few minutes (~3-5 minutes should be fine)
  6. Put the cluster back into maintenance (crm maintenance on)
  7. Restart the cluster on the primary and the scondary node (crm cluster restart)
  8. Remove cluster from maintenance mode (crm maintenance off)
  9. Cleanup resource failures (crm resource cleanup)
  10. Resource <rsc_SAPHana_***_**** (resource name)> is started on both nodes, and the roles are respectively 4:P for master and 4:S for secondary Only now it is safe to remove the saphana master/slave resource from unmanged mode (crm resource manage <resource name>)
Cluster at this point correctly picks up on the Primary/ Secondary

Cause

How can both nodes end up with same LPT values...

When cluster is stopped, SAPHana resource agent will during stop operation set LPT on secondary HANA node to 10. The primary LPT is untouched and should contain the timestamp of primary SAP HANA.
When cluster is started, SAPhana resource agent will during start operation set LPT on secondary HANA node to 10. If secondary changed between cluster stop and start this means that both nodes will effectively have a LPT of 10 and manual intervention will be needed.

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:000020690
  • Creation Date: 04-Jul-2022
  • Modified Date:05-Jul-2022
    • SUSE Linux Enterprise Server for SAP Applications

< Back to Support Search

For questions or concerns with the SUSE Knowledgebase please contact: tidfeedback[at]suse.com

SUSE Support Forums

Get your questions answered by experienced Sys Ops or interact with other SUSE community experts.

Join Our Community

Support Resources

Learn how to get the most from the technical support you receive with your SUSE Subscription, Premium Support, Academic Program, or Partner Program.


SUSE Customer Support Quick Reference Guide SUSE Technical Support Handbook Update Advisories
Support FAQ

Open an Incident

Open an incident with SUSE Technical Support, manage your subscriptions, download patches, or manage user access.

Go to Customer Center