Arangodb: Foxx: reloading a service does not remove no longer existing configuration keys

[DeividasJackus]

I'm using the latest ArangoDB of the respective release series: 3.0.10
On this operating system: CentOS Linux 7.2
Foxx service mode: Development

Manifest:

"configuration": {
    "temporary": {}
}

1. Set temporary to anything for the setting to be saved (stored in the _apps collection)
2. Remove the configuration setting temporary from the manifest as a whole
3. Service gets automatically reloaded in development mode
4. Service configuration is not updated (old temporary value still set)
5. Subsequent requests to the service result in warnings:

2016-11-09T11:18:34Z [19568] WARNING Stored configuration for app "/test" has errors:
2016-11-09T11:18:34Z [19568] WARNING Unexpected option "temporary"

[pluma]

This should be fixed in 3.1.0 (and the upcoming 3.0.11 release).

Can you check whether this still occurs after upgrading to 3.1?

Nevermind. You're talking about the stored configuration values, not the stored configuration options.

I'm not entirely sure what the best behaviour is. Discarding the unused options would result in data loss if you accidentally remove an option from the manifest during development.

[DeividasJackus]

I believe the warning should stay there, especially since this is very unlikely to be a problem with applications in Production mode. But it would be nice if Aardvark would also display values that are stored in the configuration but no longer present in the manifest and give the possibility to remove them manually through the web interface instead of doing it automatically or requiring the user to remove it from the _apps document.

[pluma]

With the new Foxx management API it will be possible to overwrite the stored values entirely. Considering Aardvark always sends the entire configuration, it would make sense for Aardvark to do the same.

I think the best behaviour would be the following:

• in development mode, patch configuration/dependencies to avoid accidents
• in production mode, replace configs/deps to clear warnings
• warnings should indicate the redundant values can be nuked by saving in production mode

[pluma]

I've addressed this problem in the devel branch which will become the upcoming 3.2 release.

Since this changes the behaviour of the web interface, the change will not backported to 3.1 or 3.0. As far as I can tell the old behaviour pre-existed in 2.x and apart from generating noise it doesn't seem to do any direct harm.