Implementing the Python hook SAPHanaSR in RHEL

As a <sid>adm user, stop the SAP HANA databases on both nodes, either with HDB or using sapcontrol, before proceeding further with changes, as seen in the following example.

hdbadm@prihana> sapcontrol -nr NN -function StopSystem

As a root user, copy the hook from the SAPHanaSR package into a read/writable directory on both nodes, as shown in the following example.

[root@prihana ~]# mkdir -p /hana/shared/myHooks
[root@prihana ~]# cp /usr/share/SAPHanaSR/srHook/SAPHanaSR.py /hana/shared/myHooks
[root@prihana ~]# chown -R hdbadm:sapsys /hana/shared/myHooks
        

Update the global.ini file on each node to enable use of the hook script by both SAP HANA instances. Ensure that you make a copy/backup of global.ini before updating the file.

See the following example for updating the global.ini at location (/hana/shared/HDB/global/hdb/custom/config/global.ini):

[ha_dr_provider_SAPHanaSR]
provider = SAPHanaSR
path = /hana/shared/myHooks
execution_order = 1

[trace]
ha_dr_saphanasr = info

The current version of the SAPHanaSR python hook uses the command sudo to allow the <sid>adm user to access the cluster attributes. To enable this, update the file /etc/sudoers as a root user with entries as shown in the following example:

# SAPHanaSR-ScaleUp entries for writing srHook cluster attribute 
Cmnd_Alias SOK_SITEA   = /usr/sbin/crm_attribute -n hana_hdb_site_srHook_PRI -v SOK -t crm_config -s SAPHanaSR
Cmnd_Alias SFAIL_SITEA = /usr/sbin/crm_attribute -n hana_hdb_site_srHook_PRI -v SFAIL -t crm_config -s SAPHanaSR
Cmnd_Alias SOK_SITEB   = /usr/sbin/crm_attribute -n hana_hdb_site_srHook_SEC -v SOK -t crm_config -s SAPHanaSR
Cmnd_Alias SFAIL_SITEB = /usr/sbin/crm_attribute -n hana_hdb_site_srHook_SEC -v SFAIL -t crm_config -s SAPHanaSR
hdbadm ALL=(ALL) NOPASSWD: SOK_SITEA, SFAIL_SITEA, SOK_SITEB, SFAIL_SITEB
Defaults!SOK_SITEA, SFAIL_SITEA, SOK_SITEB, SFAIL_SITEB !requiretty