Dynamic Configurations

Lyncode is developing a new implementation for the ConfigurationManager. Features:

• Dynamic configurations (runtime changes)
• Improved API (error handling)
• Derived values support
• Modules support
• File Based

We also think that modules should be replaced by contexts, that is, conceptually modules must be included by the main object (configuration file). So our proposal is going to work much like apache 2 configuration, it will use the properties syntax, and replace the actual concept of modules (that allows contextualization of properties) by the concept of Context (a new syntax addition).

NOTE: Our team have internally discussed about a database based implementation (https://wiki.duraspace.org/display/DSPACE/Database+Persistence+of+Configuration+State), but it would have conceptual problems. Mainly:

• How to get the database configuration? (it must be placed somewhere - not in the database)
• Reading configurations from there will put an avoidable extra task on top of the DB
• On database crashes, some services (that do not use database at all), will also crash
• Derived values aren't advisable (it would make many SQL queries to get a simple configuration value)

The under development SpringUI and its associated features made us recognize that, changing the core ConfigurationManager, is an important change to make DSpace more user friendly.