partial classes should use notify/subscribe instead of require

[DavidS]

unless the elasticsearch service automatically detects configuration changes, in which case that fact should be noted at that point.

[alvagante]

Currently relation between configuration files and service is managed by the service_subscribe parameter, requires between classes are used just to preserve correct order of resources.
Also in this case I'd concentrate on what parameter to use to define if a change to the config file triggers the service: it can be resource mapped: service_subscribe, [config_]file_notify or totally arbitrary (things like service_autorestart).