Reboot SAP HANA on node 2 - SAP HANA on AWS

Reboot SAP HANA on node 2

Description — Simulate a crash of the primary site node (on node 2) running the primary SAP HANA database.

Run node — Primary SAP HANA database node (on node 2)

Run steps:

  • Crash the primary database system (on node 2) using the following command as root: 

    sechana:~ # crm status
Stack: corosync
Current DC: sechana (version 1.1.18+20180430.b12c320f5-3.24.1-b12c320f5) - partition with quorum
Last updated: Thu Nov 12 12:16:57 2020
Last change: Thu Nov 12 12:16:41 2020 by root via crm_attribute on sechana

2 nodes configured
6 resources configured

Online: [ prihana sechana ]

Full list of resources:

 res_AWS_STONITH        (stonith:external/ec2): Started prihana
 res_AWS_IP     (ocf::suse:aws-vpc-move-ip):    Started sechana
 Clone Set: cln_SAPHanaTopology_HDB_HDB00 [rsc_SAPHanaTopology_HDB_HDB00]
     Started: [ prihana sechana ]
 Master/Slave Set: msl_SAPHana_HDB_HDB00 [rsc_SAPHana_HDB_HDB00]
     Masters: [ sechana ]
     Slaves: [ prihana ]

sechana:~ # echo 'b' > /proc/sysrq-trigger
Note

To simulate a system crash, you must first ensure that /proc/sys/kernel/sysrq is set to 1.

Expected result:

  • The cluster detects failed node (node 2), declares it “UNCLEAN”, and sets the secondary node (node 1) to status “partition WITHOUT quorum”.

  • The cluster fences node 2 and promotes the secondary SAP HANA database (on node 1) to take over as primary. 

    prihana:~ # crm status
Stack: corosync
Current DC: prihana (version 1.1.18+20180430.b12c320f5-3.24.1-b12c320f5) - partition with quorum
Last updated: Thu Nov 12 12:28:51 2020
Last change: Thu Nov 12 12:28:31 2020 by root via crm_attribute on prihana

2 nodes configured
6 resources configured

Online: [ prihana ]
OFFLINE: [ sechana ]

Full list of resources:

 res_AWS_STONITH        (stonith:external/ec2): Started prihana
 res_AWS_IP     (ocf::suse:aws-vpc-move-ip):    Started prihana
 Clone Set: cln_SAPHanaTopology_HDB_HDB00 [rsc_SAPHanaTopology_HDB_HDB00]
     Started: [ prihana ]
     Stopped: [ sechana ]
 Master/Slave Set: msl_SAPHana_HDB_HDB00 [rsc_SAPHana_HDB_HDB00]
     Masters: [ prihana ]
     Stopped: [ sechana ]

  • The overlay IP address is migrated to the new primary (on node 1).

  • With the AUTOMATIC_REGISTER parameter set to "true", the cluster restarts the failed SAP HANA database and automatically registers it against the new primary.

Recovery procedure:

  • Start node 2 (EC2 instance) with AWS Management Console or AWS CLI tools and start Pacemaker (if it’s not enabled by default).