Upgrading from ERSv1 to ERSv2

In order to upgrade from Enqueue Replication Server version 1 to Enqueue Replication Server version 2, first ensure that your SAP kernel version supports ERSv2 then complete the following steps:

1. Upgrade the ASCS instance to use ENSAv2 by following the instructions on Upgrading from ENSAv1 to ENSAv2. The same version of the Standalone Enqueue Server and Enqueue Replication Servers must be used since mixed version configurations are not supported by SAP. See the SAP documentation on ENSAv2/ERSv2 for more details.

2. Set up the virtual IP and shared file system for the ERS instance. Also create the corresponding virtual IP and filesystem resource hierarchies in LifeKeeper. They will be used in step 9 during the recreation of the ERS resource. Note: These LifeKeeper resources should be Active (ISP) on a node where the corresponding ASCS instance is currently Standby (OSU).

3. Set the following parameters in the default profile (typically located at /usr/sap/<SID>/SYS/profile/DEFAULT.PFL). These parameters must be the same for all instances:
   
   enq/enable=TRUE
   enq/serverhost=<ASCS instance host>
   enq/serverinst=<ASCS instance number>
   enq/replicatorhost=<ERS instance host>
   enq/replicatorinst=<ERS instance number>
   enque/process_location=REMOTESA

4. In the ASCS instance profile (typically located at /usr/sap/<SID>/SYS/profile/<SID>_ASCS<No>_<VIP>), set the following parameters:
   
   enq/server/replication/enable = true
   _ENQ = enq.sap$(SAPSYSTEMNAME)_$(INSTANCE_NAME)
   Execute_01 = local rm -f $(_ENQ)
   Execute_02 = local ln -s -f $(DIR_EXECUTABLE)/enq_server$(FT_EXE) $(_ENQ)
   Start_Program_01 = local $(_ENQ) pf=$(_PF)

Note: The number used for the Execute_* and the Start_Program_* parameters should be the first number not yet used for that parameter in this profile.

5. In the ERS instance profile (typically located at /usr/sap/<SID>/SYS/profile/<SID>_ERS<No>_<VIP>), set the following parameters:
   
   _ENQR = enqr.sap$(SAPSYSTEMNAME)_$(INSTANCE_NAME)
   Execute_01 = local rm -f $(_ENQR)
   Execute_02 = local ln -s -f $(DIR_EXECUTABLE)/enq_replicator$(FT_EXE) $(_ENQR)
   Start_Program_00 = local $(_ENQR) pf=$(_PF)

Note: The number used for the Execute_* and the Start_Program_* parameters should be the first number not yet used for that parameter in this profile.

6. After setting the parameters in the default, ASCS, and ERS instance profiles, restart the SAP Start Service for the ASCS and ERS instances by running the following commands (replacing <sid> with your lower-case SAP SID and <SID> with your upper-case SAP SID):
   
   su – <sid >adm -c “sapcontrol -host <ASCS VIP> -nr <ASCS Inst#> -function RestartService <SID>”
   su – <sid >adm -c “sapcontrol -host <ERS VIP> -nr <ERS Inst#> -function RestartService <SID>”

7. If you do not have an existing ERS resource in LifeKeeper that needs to be upgraded, skip to step 9. Otherwise, delete all dependencies of the ERS resource in LifeKeeper by right-clicking the resource and selecting Delete Dependency…. You may need to select Delete Dependency… multiple times in order to delete all dependencies. When you are finished, the ERS resource should exist in a hierarchy by itself with no child dependencies and no other resources dependent on it, as shown in the following image.

8. Right-click the ERS resource in the LifeKeeper hierarchy panel and select Delete Resource Hierarchy…. Select any server as the Target Server and click Next. Click Delete to delete the ERS resource on all nodes. Warning: If you did not successfully delete all dependencies between the ERS resource and other resources in the SAP hierarchy in the previous step, then this step could delete your entire SAP hierarchy.

9. Once the ERS resource has been successfully deleted on all nodes, follow the instructions in the “Create the ERS Resource” section in SAP Installation → Creating an SAP Hierarchy to create a new ERS resource and extend it to the desired cluster nodes. During the ERS resource creation, select the virtual IP and dependent filesystem resources created in step 2, if applicable. If selected, these resources will be automatically added as child dependencies in the ERS hierarchy.

10. On all cluster nodes that the ERS resource has been extended to, edit the file /opt/LifeKeeper/subsys/appsuite/resources/sap/INFO_<ERS Tag> and ensure that SAPENQREP_VERSION=2. This may require you to add the line “SAPENQREP_VERSION=2” if the INFO file does not yet contain a value for SAPENQREP_VERSION.

11. Restart the SAP system. Once the ERS instance is restarted, it will be using the enq_replicator (ERSv2) process instead of the enrepserver (ERSv1) process. This can be verified by right-clicking the ERS resource in LifeKeeper and selecting Properties….