Global Configuration Settings Are Lost
Symptoms
Altering global settings such as the Max size of an attachment, Server Base URL, or other global settings appear to be set correctly on alteration. However, upon restart of the application, the custom configurations revert to the default (such as 10MB for the max size of attachments and 5 for max number of uploads at one time).
Diagnosis
Check the bandana table for duplicate rows:
select bandanavalue from bandana where bandanakey = 'atlassian.confluence.settings';
There is a second cause to this issue that tends to happen more often in a cluster (Confluence 5.4 and earlier), but Atlassian has not yet diagnosed it. If there are no duplicate entries and your global settings are reverting, please help us diagnose the problem. Our current theory is that a null value in the cache is corrupting the values. Enable logging by adding the following values to log4j.properties:
log4j.logger.com.atlassian.confluence.setup.bandana=DEBUG, confluencelog
log4j.additivity.com.atlassian.confluence.setup.bandana=false
Cause
Because there are two rows for the settings, one row is being updated when updates are made and the other row (holding the default values) is being loaded in during a restart of the application. This behaviour generally shows up after upgrading.
Resolution
Always backup your data before performing any modifications to the database.
Delete the row in the database that contains the default values. See the diagnosis section above.