Dynamic Tiering : Unsuccessful in adding a second host

[former_member183029]

I was playing around with Dynamic Tiering feature. I looked at various user guides and help documents and was able to set it up in one system, i.e., one host for Hana and another for esserver. This works well and I was able to create tables in extended store and also this is visible from HANA cockpit.

Now when I try to add a second host for dynamic tiering, I am stuck. I do the following.

I mount the shared hana filesystem in the new system the same way I did for the first one.

In HANA host and go to .hana/shared/K9G/hdblcm and run

./hdblcm –action=add_hosts - -addhosts=<new_host_DNS>:role=extended_storage_worker:group=extended_storage

This adds the hosts but fails saying esserver not running. Log is attached here.

After this, I see that the new host is added but not behaving properly. So I use hdblcm tool again to remove the host, after completion of task, even though it says that the host is removed, next time I run hdblcm tool, I can see the host again. The log file for this also is attached. However I see the host being shown as removed in studio system property.

Also, while many trial and error, I tried to add many hosts and few of those systems are terminated, does not exist anymore. I cannot remove any of the hosts as it says that it is not able to connect to those few systems. This is a problem that if from a list of hosts, one is down, then I cannot remove others also as it complains about the down host.

Let me know if there is any way out and how can I successfully install dynamic tiering in another host.

Regards,

Subhankar

add_hosts_problem.txt.zip

remove_hosts.txt.zip

[Bojan-lv-85 · Accepted solution]

Hello Subhankar,

did you check the issues outlined in note

2068807 - SAP HANA Dynamic Tiering Option SPS 09 Release Note

Also, the esserver trace might be of interest here.

BR, Bojan

[former_member183029 · Accepted solution]

Hi Bojan,

Thank you for your reply.

I did not check the release notes previously but checked it now and could not find something similar to my scenario being reported.

Is it possible to add two hosts as esserver? For me I was able to add the first host successfully but while adding the second host, the problem happened which I mentioned above.

Also after many unsuccessful attempts, now I have two hosts which are down(unreachable) because of which I am not able to add any host or remove them properly. Posted this problem here .

Regards,

Subhankar

[Bojan-lv-85 · Accepted solution]

Hello Subhankar,

as stated in the "dynamic tiering"-administration guide:

"You can also install a second extended storage host, known as the standby, to provide failover functionality for high availability."

So you cannot install a second esserver as a worker.

Please refer to the following guides:

Dynamic Tiering Administration

http://help.sap.com/Download/Multimedia/zip-hana_options_dt/Dynamic_Tiering_Option_Administration_Gu...

Dynamic Tiering Installation

http://help.sap.com/Download/Multimedia/zip-hana_options_dt/Dynamic_Tiering_Option_Installation_Guid...

In the Installation Guide you may want to pay special attention to chapter 8.1 or 8.2 depending on the installation tools you are using.

BR, Bojan

[former_member183029 · Accepted solution]

Hello Bojan,

Thank you for your pointer. I did the installation looking at the document but completely missed this part! My bad. Thank you very much for pointing this out.

Regards,

Subhankar