SDM connecting to localhost but not Logical Hostname

[Former Member]

While installing Netweaver AS Java I faced an issue with SDM. During the install software phase(SAPINST) the SDM was not able to deploy few .SCA files. Both server0 and SDM was in Running status.

What we found that, the command telnet was working with localhost and not the logical hostname.

>telnet localhost 53308 is connecting

but >telnet ngdhidaiz1 53308 is not connecting.

So we tried with first doing a reboot of the hardware/server and later on uninstall SAP.

I started fresh installation and this time the installation was successful. I applied the latest support patches and upgraded the kernel. After this, I stopsap Java.

Now today When I tried to start the SAP the server0 and SDM started but the portal was unavailable.

I tried to check with telnet and it again was not connecting to logical hostname <ngdhidaiz1> bt localhost was connecting.

I tried to check the sap notes about the errors/problems but no help.

We can only found that there could be issues with etc/hosts file entries. But all entries were correct and no duplicate entries.

I do not have a proper way to resolve this issue other than trying to reboot the server and start the SAP.

If anyone can help on this it will be great. Thanks

Edited by: anupam giri on Jan 4, 2011 3:03 PM

[Former Member]

The issue with Logical hostname did not resolved at our end even though it was answered correctly by many of you. So there was no time for us to go ahead during that time and finally we had decided to not to use the Logical hostname and successfully completed the installations with Hostname. Later the Systems were migrated to different landscape and there are no issues.

Sorry guys for closing this after almost a year.

[Former Member]

Hi,

I dont understand. Is the SAP system completly up in SAP MMC? If yes, then is the portal page coming up? If no, then paste the std_server0.out log in this message.

Rgds,

Soujanya

[Former Member]

Hi Soujanya,

Thanks for your reply.

I will try to clear your doubt.

I have installed NW Java system on AIX not Windows. ( no SAP MMC)

The SDM was running with no errors. The server0 was running with no errors.

The only problem was that Portal page was not coming up.

So I tried to use the command telnet in AIX with localhost. It was connecting. ( telnet localhost 53308)

In the same place when I tried to use the command telnet with hostname of the server, it was not connecting. (telnet ngdhidaiz1 55308, Ideally this should also work)

Once we restarted the AIX box, the java system started and the portal page was displayed.

So we can only find the issue was with host file.

[TomCenens]

Hello

Did you install using a virtual hostname (sapinst_use_hostname) ?

We also use seperate ip addresses at our customers:

physical hostname: ip address X

virtual hostname: ip address Y

If you use above practice (combination of virtual hostname and seperate ip address) it shouldn't be a problem.

Of course you have to make sure your virtual hostname can be reached, easy to check using nslookup <virtual hostname>.

Our settings first check DNS and afterwards the /etc/hosts file if not found.

Kind regards

Tom

[Former Member]

Yes Tom, You are very near to what we faced.

We started the installation using virtual hostname concept which behaves more like alias of the physical hostname.

So we used FQDN and virtual hostname for BI java. The physical hostname and FQDN were being used for build of other landscape all in same lpar. example of host file entry.

10.225.10.23 ngdhidaiz1 FQDN

10.224.10.23 ngdhidaiz2 FQDN

While installing BI Java on the virtual host, the sapisnt throws error on the step no- install software components.

When we checked the log, it clearly throws javaexception as the Administrator user is not able to connect. So the SDM deployment stops. We tried to manually start the SDM but no luck ! Same error Administrator cant connect.

So when we started finding the RCA, we found some of the Java services are using the physical hostname and some were using virtul hostname. Then we found that the telnet is working for the localhost not the virtualhost. The portal was not available even though the server0 and SDM were running.

So we scrapped the installation and begin installing using the physical hostname. The installation was successful and everything was fine. But before that we have to restart the AIX box to resolve any issues with OS or host file.

Still we believe the culprit is hostfile or might be the sapinst. Still I dont have a proper RCA.

If you can help me , it would be great.

[TomCenens]

Hello

i'll give one example using the data you posted:

10.225.10.23 ngdhidaiz1 ngdhidaiz1.<domain>.<ext>

(full to short makes more sense logically FQDN ngdhidaiz1)

Your physical hostname should be someonething else for example

XX.XXX.XX.XX ngphys1 ngphys1.<domain>.<ext>

If you have a seperate ip address for your physical host then you should install using SAPINST_USE_HOSTNAME=ngdhidaiz1 (or place SAPINST_USE_HOSTNAME in your env variables with the value) and preferably place the above entries in your DNS. Then it doesn't have to be specified in the hosts file.

You just need to make sure you can then reach ngdhidaiz1 when you perform an nslookup

nslookup ngdhidaiz1 should return ip address 10.225.10.23

If you install your SAP system as shown above you should not have any issues with malconfiguration of java services (containing wrong hostname).

Where asked for the virtual hostname you use ngdhidaiz1 and only in the abap parameters where it specificially sais FQDN you use the FQDN.

Kind regards

Tom

Edited by: Tom Cenens on Jan 5, 2011 12:00 PM

[Former Member]

I very much agree with Tom. We had the same issue with distributed installation using virtual hostname and nslookup was failing.