SAP HANA System Properties & Configuration Files

HANA system consist of multiple configuration (*.ini ) files that defines various parameters/properties as part of system configuration.

These configuration files contain parameters for global system configuration (global.ini), as well as the configuration of each service in the system (for example, indexserver.ini).

Each configuration file is separated into sections which consist of properties of the same category. These properties can be configured on various layers.

Following are the layers:

  • Default: The default value for the property if not mentioned in other layer. Should not be edited.
  • System: User/Admin configured property for the whole system (configurable in the system database). If a system-specific value is not configured for a property, the default value applies.
  • Host: The host specific value for the property (configurable in the system database). Mostly used in case of scaleout system for defining properties which can be host-specific. If a host-specific value is not configured for a property that can be set at host level, the system-specific value applies.
  • Database: The database specific value for the property (configurable in the system or tenant database). For some properties, it is possible to set database specific values. If a database specific value is not configured, the system specific or host specific value applies.

Default location of configuration files:

/usr/sap/<sid>/SYS/global/hdb/custom/config/global.ini -> Contains configuration setting applicable for all services on all hosts

/usr/sap/<sid>/SYS/global/hdb/custom/config/<service>.ini -> Applicable for a specific service (e.g. nameserver) for all hosts

/usr/sap/<sid>/HDB<inst>/<host>/global.ini -> Valid for all services on specific host

/usr/sap/<sid>/HDB<inst>/<host>/<service>.ini -> Applicable for a specific service (e.g. nameserver) on a specific host

How to define/modify a parameter:

Following are the popular ways of setting a hana parameter:

  • Hana Studio -> Administration Editor -> Configuration tab
  • SQL
    ALTER SYSTEM ALTER CONFIGURATION ( <filename>, <layer>[, <layer_name> ] ) { SET | UNSET } ('<section>','<property>') = '<value>' [ WITH RECONFIGURE ] [ COMMENT <comment_string> ] 
    WITH RECONFIGURE option does the immediate effect on the system
  • Directly in .ini files at OS level (To have immediate effect, need to perform hdbnsutil -reconfig)
Changes in few configuration files/parameters require restart while some doesn't.
For example most of the global.ini related parameters do no require restart, while daemon.ini related changes require restart.