Configure SAP Standalone Gateway integrated with High Availability ASCS instance

Microsoft

Feb 03, 2025

For businesses running on SAP systems, a resilient environment is essential for uninterrupted operations. This includes ensuring high availability of the standalone SAP Gateway. Instead of a separate standalone SAP gateway deployment, integrating it with the ASCS high availability offers a simpler, more efficient, and less maintenance-intensive solution. This approach also ensures the gateway's high availability alongside the ASCS. This blog post details how to implement this streamlined integration on Linux OS, and its advantages.

Pre-requisites

Before proceeding with the configuration, ensure that you have reviewed 1010990 - Configuring a Standalone Gateway in an HA ASCS instance - SAP for Me, which describes the steps to configure a standalone gateway in a Windows environment. This document will use the information provided in SAP Note 1010990 to extend the configuration process to a Linux environment, while capturing and addressing the necessary changes specific to Linux OS.

Configuration steps

Edit “/sapmnt//exe/uc/linuxx86_64/scs.lst” and add the following lines.
```
gwmon
gwrd
```
NOTE: It is possible that these entries are already present in the file. If they are, then no further action is required.

Add following lines in ASCS profile: /sapmnt/SID/profile/SID_ASCS_<ascshost>

#-----------------------------------------------------------------------
# Start gateway
#-----------------------------------------------------------------------
_GW = gw.sap$(SAPSYSTEMNAME)_$(INSTANCE_NAME)
Execute_ = local rm -f $(_GW)
Execute_ = local ln -s -f $(DIR_EXECUTABLE)/gwrd$(FT_EXE) $(_GW)
Restart_Program_ = local $(_GW) pf=$(_PF) -no_abap

Check the gateway port definitions are maintained in /etc/services files

sapgw<no>       33/tcp      # SAP System Gateway Port
sapgws<no>      48/tcp      # SAP System Gateway Security Port

NOTE: <no> is the value of the ASCS profile parameter SAPSYSTEM

Restart the SAP ASCS instance. If you have a clustered High Availability (HA) setup, you can either restart the service by putting the cluster in maintenance mode or stop and start the ASCS resource within the cluster. To check if the SAP Gateway process has started and is running, execute the following command.
```
# sapcontrol -nr <no> -function GetProcessList 
```
Status of SAP gateway process after integrating with ASCS instance.

Testing and validation

To test the setup, register the program on the gateway. Follow the instructions in SAP Note 353597 - Registration of RFC server programs to register the server program on the gateway.

In this example, I’m using the existing RFC destination (IGS_RFC_DEST) where we will be registering IGS.NW1 program ID. To ensure the RFC destination uses the standalone gateway, follow these steps:

Register the “IGS.NW1” program on the standalone SAP gateway host integrated with the SAP ASCS instance:
```
sidadm> rfcexec -t -a IGS.NW1 -g slesascs -x sapgw00 -s NW1 &
```
Edit “IGS_RFC_DEST” to enter the gateway host and gateway service details:
- Gateway Host: <hostname of ASCS instance where gateway is running>
- Gateway Service: sapgw<no>
Edit RFC and enter gateway information in "Gateway Host" and "Gateway service" field.
Perform "Connection Test".
Result of test connection.