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Prerequisites

Make sure you have performed the OS and DB level preparations for the Managed System Configuration as described here: Prepare Managed System Setup for SAP HANA

Check SAP HANA MDC System in LMDB

In LMDB the system DB will register with the system SID and the tenants will register with their given SIDs. 

To find out, which tenant belongs to which SYSTEM DB, you can do the following:

  • open SYSTEM DB or tenant DB in the LMDB 
  • click in the "System Overview" on the "Details" button
  • select "Associated Instances" tab
  • click on SAP_HDBSystemSubDatabase association

In this view, in the column "Associated Role", you can see which one (groupcomponent) is the System DB and which one (partcomponent) is a tenant.

Managed System Configuration for HANA MDC

If the information supplied from SLD, correctly displayed in the LMDB, you can perform the Managed System Configuration.

Please note, the Managed System Configuration has to be performed for the SYSTEMDB as well as for each tenant.

From the configuration point of view, the setup steps are pretty much the same as for a single HANA DB, but you should pay attention to the steps below.

In the step "Enter System Parameters" where the DB connection is set up, please make sure that the correct database name is pulled in the field "Instance Name". For the SYSTEMDB it will first show the global SID and then after the connection is made it will change to SYSTEMDB.

In the next step "Enter Landscape Parameters" you have to make sure you put in the correct path for installation path and log path for SYSTEMDB and each tenant.

The default installation path is /hana/shared/<SYSTEMDB-SID>. If the path has been changed during the installation, adjust it accordingly. However it should be the same for the SYSTEMDB as well as for all tenants. Please note that the auto-filled default value will be /hana/shared/<Tenant-SID>/. This path doesn't exist and you need to adjust this value.

The instance installation path is under /usr/sap/<SYSTEMDB-SID>/HDB<Inst. No.>. Also here you have to adjust the paths during the setup of the tenant DBs, as again the default auto-filled value will contain the

The instance log path differs between the SYSTEMDB and each tenant till Solution Manager 7.2 SP6.

  • For the SYSTEMDB it is the default log path under /usr/sap/<SYSTEMDB-SID>/HDB<Inst. No.>/<host>/trace/
  • For the tenants the log path changes to /usr/sap/<SYSTEMDB-SID>/HDB<Inst. No.>/<host>/trace/DB_<Tenant-SID>/

 

As of SP7 and higher the installation log path for the Tenant is the same as for System DB, means without /DB_<Tenant-SID>/ at the end.

Setup for SAP HANA with multiple hosts

If your MDC system runs on several hosts it is possible to set up tenants so that they only run on specific hosts. This tenants will not have a DB_<Tenant-SID> sub-directory in the trace folder for hosts it is not running on.

However, even if not actively used by the indexserver the second instance will show up in the step "Enter Landscape Parameters" because shared services from this tenants run on it. You cannot just leave the default value here (which would be the trace directory of the SYSTEMDB), because if you do, this will lead to double monitoring. The trace files will be monitored by the SYSTEMDB as well as by the tenants. This would lead to problems in the monitoring and also the reporting.

The best way to avoid this, is to enter the DB_<Tenant-SID> extension to the path even if this path doesn't exist. This will lead to grey metrics, but at least not to double monitoring and wrong reporting. To avoid a warning when saving the parameter you should uncheck the "Check existence of paths when saving" checkbox when you save this parameter.

 

System Monitoring of SAP HANA MDC Systems

  1. As of Solution Manager 7.2 SP5 new templates 'Tenant Database Instance' and 'Tenant Database Instance (instance level separated)' were introduced to support the System Monitoring of MDC.

  2. System Monitoring of system replication scenarios with automatic adjustment of the monitoring in case of a fail-over is not supported for MDC systems
  3. All metrics based on SAP Hostagent („HDB <servicename> Status“ in the alert group „Database Service Availability“) can be used for MDC as of SAP Solution Manager 7.2 SP5.

 

 

 

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