HANA Express 2.0 SP03 - Nameserver doesn't come up (crashes)

[Gunter]

Dear experts,

I tried installation of HXE and it doesn't get very far. I wonder what it could be. It's the nameserver that crashes:

hxeadm@gunter-hxe:/usr/sap/HXE/HDB90> ./exe/hdbnameserver 
unclean shutdown of service instance with pid 28090
service startup...
accepting requests at 127.0.0.1:39001
searching for master nameserver gunter-hxe:39001 ...
assign as master nameserver. assign to volume 1 started
service startup...
Checking for recovery request ...
Loading topology ...
Opening persistence ...
run as transaction master
Loading licensing ...
Segmentation fault (core dumped)

Any idea what that could cause? I successfully ran a HXE on the same server before, no hardware changed. Or any advice how to properly read the crashdump file? I attached it to this post.

nameserver-gunter-hxe39001crashdump20180726-153617.txt

[BJarkowski]

Thanks Gunter,

in one of the log files I see this entry:

[2112]{-1}[-1/-1] 2018-07-26 15:36:15.642142 e NameServer       TREXNameServer.cpp(00462) : failed to open shared memory. id=1, rc=3, os-error=2 (No such file or directory). disabling shared-memory

There is a note associated with this error:

2490368 - Nameserver not running - failed to open shared memory. rc=3, os-error=2

I would give it a try.

If that won't help, maybe a good solution would be to reinstall the OS as well?

[Gunter]

Hi Bartosz,

thanks for helping. I have added some more log files. There is no /var/log/messages in Ubuntu. I also went through complete uninstalling and re-installing including fresh downloading the tar-files.

If you need any other specific file, let me know please. I would love to get behind the problem. Meanwhile it's a great learning about HANA DB folderstructures and startup procedure 🙂

[BJarkowski]

Hi,

did you find the solution? I'm curious what was the root cause 🙂

[Gunter]

Hi Bartosz,

I spent some more time on it yesterday and also followed the note but I couldn't manage to find the root cause. I have installed HXE a couple of times already on different servers and this is the first time I have such an issue. So I think it must be related to something I did special this time.

First, I use Ubuntu LTS 18.04 (however I had the previous installation successfully running on the same hardware with that OS).

Second I use tinc so that I can access my server from everywhere which uses the network interface /dev/net/tun to channel the network traffic. I will first shutdown this service then try to run the server again. If that doesn't work go for a re-install (however it's already my second fresh install). Will keep you updated!

[BJarkowski]

Thanks.

Did you reinstall Ubuntu as well? I understand that you had a HXE previously installed on the host, so maybe some leftovers are causing the issue?

[Gunter]

Ok, Bartosz, now I got it up and running. HXE is not compatible with the tinc service. I just shut it down by

sudo systemctl stop tinc

then uninstalled HXE and now going for a fresh install. I already see that nameserver came up and it's going through the regular installation steps. Of course, I now need to solve my problem how to reach the server through the internet in a secured way but that's a different story. If you have any hint that HANA has problems when several Networks cards are installed or particular when using the linux "tun" please do let me know.

[lsubatin]

Hi, Gunter, which version of Ubuntu is this?

[Gunter]

Hi Lucia,

thanks for asking. Its Ubuntu 18.04 LTS. I have a certain confidence it would be failing with 16.04 as well. Without tinc service up HXE just runs as smooth as it did on 16.04.

Tinc makes use of the /dev/net/tun (tun0) interface which exists on every(?) Linux. If it's active, the hdbnameserver-service crashes with "Segmentation fault". Which is the end of the startup of HANA DB. Is there anything to be considered if more than one nic is present in a HDB-Server? Maybe HDB doesn't know which IP address to stick to? I don't think it's related to tinc itself as this is quite mature. Of course it's not the end of the world as in a productive environment you wouldn't run the VPN server on the HDB. 🙂 Still, if it can be solved it would be great. I'm happy to experiment as I can reproduce the error now.

[BJarkowski]

Hi,

not sure how useful it will be, but I was able to find a SAP Note that describes this (or very similar) issue:

2518491 - SAP HANA fails to start

Could you please attach more logs? I would like to see the nameserver log files (not only crash dump) and Linux log file (/var/log/messages).