SAP installation
During the SAP installation, use the high availability option of SWPM, install ASCS on
hahost01 using the virtual hostname ascshost, and install ERS
on hahost02 using the virtual hostname ershost.
The ascshost is mapped to (DNS or /etc/hosts) the ASCS
overlay IP, and ershost is mapped to the ERS overlay IP.
When SAP installation is complete, install and configure the Database, the SAP Primary Application Server (PAS), and optionally, the Additional Application Server (AAS). SAP NetWeaver installation steps are detailed on the SAP help portal.
Maintaining sapservices
RHEL
On both ASCS and ERS nodes, ensure that the following two lines are commented in the /usr/sap/sapservices file.
#!/bin/sh #LD_LIBRARY_PATH=/usr/sap/HA1/ASCS00/exe:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH; /usr/sap/HA1/ASCS00/exe/sapstartsrv pf=/usr/sap/HA1/SYS/profile/HA1_ASCS00_hahost01 -D -u ha1adm #LD_LIBRARY_PATH=/usr/sap/HA1/ERS10/exe:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH; /usr/sap/HA1/ERS10/exe/sapstartsrv pf=/usr/sap/HA1/ERS10/profile/HA1_ERS10_hahost02 -D -u ha1adm
SLES
Ensure that the /usr/sap/sapservices file holds both the entries (ASCS and ERS) on both cluster nodes.
Modify the file by copying the missing entry from both hosts.
#!/bin/sh LD_LIBRARY_PATH=/usr/sap/HA1/ASCS00/exe:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH; /usr/sap/HA1/ASCS00/exe/sapstartsrv pf=/usr/sap/HA1/SYS/profile/HA1_ASCS00_hahost01 -D -u ha1adm LD_LIBRARY_PATH=/usr/sap/HA1/ERS10/exe:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH; /usr/sap/HA1/ERS10/exe/sapstartsrv pf=/usr/sap/HA1/ERS10/profile/HA1_ERS10_hahost02 -D -u ha1adm
SAP profile parameter adjustment
For the ASCS, ensure that the start command is Start_Program_xx for enqueue
server. If it is Restart_Program_xx, change it to
Start_Program_xx. This lets the SAP framework know not to self-restart
the enqueue process. This is important because restarts can lead to a loss of locks.
Example profile file:
/usr/sap/HA1/SYS/profile/HA1_ASCS00_ascshost
ENSA1
Start_Program_01 = local $(_EN) pf=$(_PF)
ENSA2
Start_Program_01 = local $(_ENQ) pf=$(_PF)
Alternatively, you can limit the number of restarts for services. (Note that in the
case of ASCS, this limits the restart of the message server.) For the ERS, ensure that
the start command is Start_Program_xx for the enqueue replication server.
Example profile file:
/usr/sap/HA1/SYS/profile/HA1_ERS10_ershost
ENSA1
Start_Program_00 = local $(_ER) pf=$(_PFL) NR=$(SCSID)
ENSA2
Start_Program_00 = local $(_ENQR) pf=$(_PF) NR=$(SCSID)
Note: to prevent automatic start of the ASCS/ERS with Amazon EC2 instance start, set the
Autostart parameter to 0 in both the ASCS and ERS instance profiles.