When operating the HANA system, configuration changes are required for various reasons such as performance or stability improvement. If you do not keep track of these changed configurations somewhere, you may have difficulty knowing the old values when you play back or if the set value is still needed e.g. in case of a recommended workaround for an issue that is now fixed.
Of course, configuration changes are recorded in the index server trace (or nameserver trace in case the value is set for the systemDB) with the ALTER SYSTEM CONFIGURATION command, so you can check the existing changes through the indexserver trace with the grep command on the OS as shown below.
grep -I "ALTER SYSTEM ALTER CONFIGURATION" indexserver_xxx_001.trc
Please note that the changes are recorded when you made changes from Configuration Tab in HANA Studio or execution with ALTER SYSTEM CONFIGURATION command. However, the ini configuration file modified manually will not be recorded in the traces.
From HANA 2.0 SPS03 on, SYS.M_INIFILE_CONTENT_HISTORY view is provided for configuration change history. You can track the configuration change history even if you do not write down the setting value somewhere or search the indexserver trace. The view makes it easy to see who made the changes, which values were applied, and why.
SELECT TIME, FILE_NAME, LAYER_NAME, USER_NAME APPLICATION_NAME, APPLICATION_USER_NAME, SECTION, KEY, VALUE, PREV_VALUE, COMMENTS FROM SYS.M_INIFILE_CONTENT_HISTORY;
How to specify a reason/comment for the changes
Using extended SQL syntax, you can specify a reason or comment (string literal) when you make a change of a parameter as below.
Please refer ALTER SYSTEM ALTER CONFIGURATION Statement (System Management) section in SAP HANA SQL and System Views Reference for more details.
ALTER SYSTEM ALTER CONFIGURATION ('indexserver.ini', 'DATABASE', 'C11') SET ('memorymanager', 'allocationlimit') = '500000' WITH RECONFIGURE COMMENT 'Reverting to previous setting';
- The changes made by tools such as hdbnsutil are not recorded.
- The manual changes to ini configuration file are not recorded.