Dynamic Tiering : Unsuccessful in adding a second host
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.
Bojan Dujic replied
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
Dynamic Tiering Installation
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.