There are a few concepts that you should be familiar with before starting to work with the Hydrosphere platform.


The concepts described below are related to the serving part of the Hydrosphere platform.


A model is a machine learning model or a processing function that consumes provided inputs and produces predictions or transformations. Within the Hydrosphere platform we break down the model to its versions. Each model version represents a single Docker image containing all the artifacts that you have uploaded to the platform.


Servable is an instance of a model version which could be used in application or by itself as it exposes various endpoints to your model version: HTTP, gRPC, and Kafka.


Each model relies on its runtime. A runtime is a separate service with the predefined interface that is used to run your model. We have already implemented a few runtimes, which you can use in your own projects.


A model version itself is not capable of serving predictions. To do that, you would have to create an application. An application is a publicly available endpoint to reach your models. You can define complex pipelines where a single request goes through multiple model versions. A pipeline exposes various endpoints to your models: HTTP, gRPC, and Kafka.


The concepts described below are related to the monitoring part of the Hydrosphere platform.


Every model can be monitored with a set of metrics. Conceptually, metrics can be grouped into the following categories:

  • Per-Request Metrics — every request is evaluated against all assigned to the model metrics. Per-request metrics allow you to make immediate judgments against an incoming request.
  • Batch Metrics — requests are collected into a batch, and the batch is proceeded to the assigned metrics for calculation.
  • Overall Metrics — metrics are calculated against all data that was collected during production inference. Overall, metrics give you an idea of what all your data looks like through profile calculations.