In MLServer, each loaded model can be configured separately. This configuration will include model information (e.g. metadata about the accepted inputs), but also model-specific settings (e.g. number of parallel workers to run inference).
This configuration will usually be provided through a model-settings.json file which sits next to the model artifacts. However, it's also possible to provide this through environment variables prefixed with MLSERVER_MODEL_ (e.g. MLSERVER_MODEL_IMPLEMENTATION). Note that, in the latter case, this environment variables will be shared across all loaded models (unless they get overriden by a model-settings.json file). Additionally, if no model-settings.json file is found, MLServer will also try to load a "default" model from these environment variables.