SAP HANA SPS 11 supports multitenant database containers. This is a fascinating and very useful feature. I happened to have access to a fresh ver. 110 HANA system, which was installed in single-container mode. However, as it turned out, I needed the multitenant feature. Here I would like to discuss the issues that came up, and the solutions that were found, during the conversion of this the SPS 110 single-container system to multitenant.
The steps of the conversion are clearly described in the SAP HANA Multitenant Database Containers - Operations Guide document. N. van der Linden gives an excellent walk-though of the process as well. Another useful example is provided by Eleanor Teuten.
The conversion begins with calling 'python /usr/sap/<SID>/HDB<instance>/exe/python_support/convertMDC.py'. Unfortunately in my case, the script failed to complete successfully. It failed to start the instance, after timing out.
Repeated attempts to start the system ('HDB start'), and investigation of the processes ("watch 'sapcontrol -nr 00 -function GetProcessList'") and trace files revealed that the 'diserver' was to blame. In 'diserver_hana.30025.000.trc' I found:
[62652]{-1}[-1/-1] 2016-02-04 19:08:32.288880 i HANA_DI_DISERVER HDIServer.cpp(00128) : waitForMasterIndexserver(): Master indexserver not found
[62652]{-1}[-1/-1] 2016-02-04 19:08:32.288897 i HANA_DI_DISERVER HDIServer.cpp(00131) : waitForMasterIndexserver(): Retrying again in 5 seconds
The above two lines kept repeating every 5 seconds until a final timeout, when the 'HDB start' exited with failure.
After the conversion with 'convertMDC.py', my effective configuration for 'daemon.ini / diserver / instances' was '1', set on the 'host' layer ('/usr/sap/<SID>/HDB<ii>/<host>/daemon.ini'). I set the number of 'diserver' instances to the default '0':
[diserver]
instances = 0
This allowed 'HDB start' to complete successfully and all processes became green. After this, I completed the conversion to multitenant.
The 'diserver' seems to belong to the 'SAP HANA Deployment Infrastructure (HDI)', which is a new feature in SPS 11.
In the meantime HANA Database version 111 was released. My colleague patches our system to it, and we once more enabled 1 instance of 'diserver', but this again could not connect to the master index server.
It might be that the 'diserver', being a new feature, is not completely well integrated with 'convertMDC.py' yet.
The question is:
- How to enable an instance of 'diserver' on a multitenant HANA Database?
Best regards,
Laszlo