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ConfigService

TODO

API

  • getValue(String key, String identityParm...)

  • getConfigContext(String contextId, String identityParm...)

  • getConfigContexts(String identityParm...)

Identity

  • Use a SSO service to obtain a token for identity.

  • Environment variables like IP address, serviceId (e.g. com.company:app1:1.2.3), environment,

    • No authentication really

Integration

  • Stateless

  • Synchronous

  • Multiple endpoints

    • E.g. JSON, XML, JMX/MBeans

  • Use environment variable to obtain the url to the ConfigService.

Configuration consumer

Usage does not require a client library, but we could create a library to reuse a few nice features.

  • Local configuration cache

  • Separate booted from running state

    • Infer a booted as a separate state from running. Can implement retry-functionality to improve reliability. (Can try to initialize the Spring AppContext later if it fails because an external service is unavailable.
    • Catch exceptions related to state change from booted to running and handle these appropriately.
    • Don't get stuck in failed state. If we don't try to recover or something from a failure, it is better to just do a System.exit() and die.

Server

  • Possible to share configuration parameters between applications/nodes.

    • A single entry to update a property, even if it is used multiple places.
    • Example: Two services that communicates with JMS need to use the same JMS-server.

  • Node specific configuration must be possible

  • A configuration must be connected to a version

    • Traceability: Possible to save a configuration so it can be restored later.
    • We can achieve traceability and versioning by indexing the configuration. Using Lucene as backend should achieve this goal and will additionally give us advanced search functionality for "free".

  • Isolation between environments

    • Ensure that test environments do not affect production or each other.

  • Separate different types of configuration

  • Concept of a context which can be given a name/id

    • The idea is to support multiple sets of configuration for a single client.

Configuration admin client

  • GUI to add, remove and change configuration.

  • JMX

Old notes

ConfigService Notes

ConfigService Notes2