Skip to Content
0
Former Member
Jun 18, 2016 at 12:23 PM

SAP Application Server System still goes over wrong Network Adapter

301 Views

Hello experts,

WE recently did a DMO from Oracle to SAP HANA. SAP HANA now runs, of course, on a different physical host than the SAP Application Server. Both hosts are connected via different network adapters

-. Frontend Adapter with 1 Gbit/s - is only a fall back connection between Application Server and HANA, the interfaces are used for users and administrators to connect via frontend (SAP Logon, SAP HANA Studio)

- Backend Adapter with 10 Gbit/s. This adapter should actually be primarily used for communication between SAP Application server and HANA.

Here are the ip adresses and hostnames of all adapters

SYstem Adapter IP of adapter hostname of adapter SAP Application eth0 172.17.16.53 sapfrontend SAP application eth1 192.168.151.53 sapbackend SAP HANA eth0 172.17.16.54 hanafrontend SAP HANA eth1 192.168.151.54 hanabackend

Now, when I measure on the SAP Application server with command lines like

OS>netstat -an | grep <backend IP of SAP HANA>

OS>netstat -an | grep <frontend> IP of SAP HANA>

OS>iftop -i eth0

OS>iftop -i eth1

Then I see that there is no connection on eth1 (backend) from SAP application server to SAP HANA. The system uses the slower Frontend Adapter and I want to change that whitout doing any magical tricks with some iptables rule oder fumblin around in the /etc/hosts, because that would be the ugly way.

So what I did was:

  • change PAramter sAPDBHOST in DEFAULT.PFL of SAP System from hanafrontend to hanabackend
  • changed primary host name on SAP HANA via command line
    OS>hostname hanabackend
  • used hdblcmgui to rename SAP HANA primary hostname from hanafrontend to hana backend

HANA is a single host system, so SAP HANA internal commnication is set to "local".

I restarted both systems, even sapstartsrv, and did cleanipc <SAP instance> remove and slibclean on SAP Application server because it's AIX.

But the SAP application server still uses the frontend adapter to connect to SAP HANA, even though when I look in the developer traces, for example in the log of dev_w0, it says "trying to connect to SAP HANA database running on hanabackend". So the correct hostname is being recognized. Why does it still use the frontend adapter?

just for notice, the SAP Application server has in its porfoile still set the following parameters

Parameter Value SAPGLOBALHOST sapfrontend SAPFQDN servers.emea.dir SAPLOCALHOSTFULL $(SAPLOCALHOST).$(SAPFQDN) rdisp/mshost sapfrontend rdsip/msserv sapms<SAPSID> SAPTRANSHOST sapfrontend enque/serverhost sapfrontend

Meaning that the primary host name of the SAP system is the frontend one. But that shouldn't have to do anything with the backend connection, right?