Discovery HTTP interface

Discovery’s HTTP interface provides a web-management interface and two metric end-points. The web-management interface provides you with a central overview of licensing, component connectivity, and key performance metrics in your deployment. The metric end-points provide performance metrics in Prometheus and JSON format.

Web interface

Discovery’s web interface provides a visualisation of the components in your deployment, the connections between them, and key performance metrics.

discovery web 1
Discovery web interface

Services pane

The Services pane lists all components connected to Discovery, with DataSource I/O rates (sent + received) displayed for all components except Liberator, which displays the number of current logins. I/O rates for Liberator are displayed in the connectivity diagram.

discovery web services
Services pane

Connectivity diagram

The connectivity diagram illustrates components and the connections between them. Each component displays a DataSource I/O rate (sent + received) and a status disc indicating whether the component is UP or DOWN.

discovery web diagram
Connectivity diagram

The thickness of connecting lines provides a graphical representation data throughput. Hover over a connection to reveal a tooltip with metrics for throughput (updates per second) and latency (milliseconds).

discovery web connection tooltip
Connection metrics

Connecting lines can also provide visual warnings of latency bottlenecks. Click the cog icon ( ) to open the Settings panel for the diagram. Set a Latency Threshold (ms) and choose a Latency Visualisation method.

In the screenshot below, the Latency Threshold has been set to 5ms and the Latency Visualisation method set to 'dash'. The latency between Transformer and Liberator is 10.5ms, which exceeds the new threshold, and so the connection is rendered as a dashed line.

discovery web latency
Settings panel with a latency threshold of 5ms

Monitorables pane

Click on a component in the Services pane or Connectivity diagram for detailed metrics on the component.

discovery web monitorables
Monitorables pane

The Liberator component also provides a separate status pane, Liberator Status, similar in style to the Liberator Status Page published by Liberator’s LiberatorWebsite blade:

discovery web monitorables liberator

Discovery retrieves metrics from components using the following interfaces:

Component Monitoring interface

Liberator

Sockmon

Transformer

Sockmon

Java DataSource

JMX

Metrics

Discovery’s Spring Boot stack exposes metrics at the following URIs:

Format URI

Prometheus

/actuator/prometheus

JSON

/actuator/metrics

Configuring Discovery’s HTTP interface

To change Discovery’s HTTP port number, edit server.port in the Discovery server’s config/application.properties file.

To change which Spring Boot actuators are enabled, edit management-endpoints-web-exposure-include in the Discovery server’s config/application.properties file.