One of the ongoing challenges we face with PredictionIO is the separation of Engine & Eventserver APIs. This separation leads to several problems:
1. Deploying a complete PredictionIO app requires multiple processes, each with its own network listener 2. Eventserver & Engine must be configured to share exactly the same storage backends (same `pio-env.sh`) 3. Confusion between "Eventserver" (an optional REST API) & "event storage" (a required database) These challenges are exacerbated by the fact that PredictionIO's docs & `pio app` CLI make it appear that sharing an Eventserver between Engines is a good idea. I recently filed a JIRA issue about this topic. TL;DR sharing an eventserver between engines with different Meta Storage config will cause data corruption: https://issues.apache.org/jira/browse/PIO-96 I believe a lot of these issues could be alleviated with one change to PredictionIO core: By default, expose the Eventserver API from the `pio deploy` Engine process, so that it is not necessary to deploy a second Eventserver-only process. Separate `pio eventserver` could still be optional if you need the separation of concerns for scalability. I'd love to hear what you folks think. I will file a JIRA enhancement issue if this seems like an acceptable approach. *Mars Hall Customer Facing Architect Salesforce Platform / Heroku San Francisco, California
