The Ercole Project


The Ercole projects is made up of the following components/projects:

  • Ercole Server: Provides the data collection endpoint and methods for the User Interface.
  • Ercole Web: the user interface: dashboard, alerts, host details, etc.
  • Ercole Agent(s): Data collectors to be installed on the target machines.

Ercole Agents are typically packaged as daemons / services for the supported platforms. Once started, the agent periodically executes a set of operations:

  • launch a series of 'fetchers': shell commands to retrieve System and Oracle instance information
  • transform the collected data into a JSON object
  • send the data to the Ercole Server via a HTTP POST request

The Ercole Server is responsible of:

  • Receiving the host data from the agent via HTTP
  • Storing the data in a PostgreSQL database
  • Archiving previous host information if already present in the db
  • Processing the incoming host data and generating alerts (i.e., a new feature has been activated)
  • Serving data to the Web User interface via a REST API

Data format

The PostgreSQL database main tables are:

  • current_host: contains a few 'search-friendly' columns (hostname, databases, environment) and two columns (host_info and extra_info) to store the detailed json data for the host. Note the columns are LONGTEXT, casting to json/jsonb happens at query level in the server methods.
  • historical_host: a copy of current_host, holds historical data
  • alert: alerts generated by the server
  • license: number of purchased Oracle Licenses (declared by the user in Ercole Web).


Currently Ercole-Server embeds Ercole agents and Ercole Web, so it can be deployed as a standalone jar.

It is recommended to set up a proxy server (nginx, apache) in front of Ercole Server to provide SSL communication between the agents and the server.

Future versions

In the future (version 2.x) we're considering a few enhancements that will likely split up the architecture and impact the data format:


  • Move to mongodb or other json-based storage
  • Create separate services:
    • Alert: Generate alerts, send notifications. Expose data for 3rd party usage (i.e. prometheus)
    • API: provides REST APIs for the User Interface
    • Data: receives data from the agent
    • Repo: provides a yum repository (proxy?) for the agent binaries
  • Implement a self-update mechanism for the agents, move agent packages to a dedicated repository/service
  • Use Go as preferred language for services

Note that this list is subject to change, new ideas, etc.