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OpenNMS Horizon

Horizon is an open-source solution that helps you visualize and monitor everything on your local and remote networks. It offers comprehensive fault, performance, traffic monitoring, and alarm generation in one place. Highly customizable and scalable, Horizon easily integrates with your core business applications and workflows.

Features include remote data collection, application perspective monitoring, alarm correlation, scalability, business service monitoring, and comprehensive management of inventory, faults, alarms, events, performance, and traffic.

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Horizon 30

Insight, integration, and lovability

We've packed a lot into our 30th major Horizon release, including features and enhancements for improved integration, insight and lovability for our user community.

New in Horizon 30:

Official Plugin API for Custom Plugin Development

The OpenNMS Plugin API (formerly OIA) provides a stable base to build plugins to extend the configuration of OpenNMS, consume its outputs, and expose expanded functionality.

OpenNMS has always provided many integration points, offering flexibility for building the monitoring solution an organization needs. The Plugin API identifies, documents, and provides ongoing compatibility guarantees for those integration points, so plugin creators can write code that targets a set of interfaces and works with a broad range of OpenNMS releases. Learn more

NetFlow Thresholding

OpenNMS administrators can now define more fine-grained monitoring of network circuits by leveraging NetFlow data to help detect traffic anomalies. For instance, if VOIP or streaming video traffic is consuming excessive bandwidth, Horizon can help spot the pattern. By defining threshold values based on business requirements, users can know when a particular application is using more bandwidth than expected in real time.

Distributed flow threshold evaluation lets organizations keep up with increasing flow volumes without the need to grow the core OpenNMS Horizon application tier.

New Device Provisioning Configuration Experience

Horizon 30 features a new way to configure the core provisioning subsystem, providing both a new user interface and a powerful API back end.

Synchronize inventory against external sources – including HTTP and DNS – and tune the subsystems's performance via the web UI or the REST API. The web UI eliminates command-line tasks while also providing real-time validation of inputs for front-end users. The the new API back end gives even more power and flexibility to advanced users.

Backup your Network Device Configuration

OpenNMS now persists configuration information from network devices so that users can review the configuration history.

Users can manage device configuration backups, including viewing backup history for a single device and downloading either individual or multiple configurations. Filter, search, and compare configurations at different points in time for a specific device, and manually perform a device configuration backup from one interface as needed.

View and sort backup status to see all failed backups, and initiate manual backups with a single click after selecting all failed devices.

Event-sourced data collection

OpenNMS can now persist metrics embedded in autonomous messages sent to OpenNMS, such as SNMP traps and syslog messages, for visualization and thresholding.

OpenNMS has always been great at receiving and processing events, and collecting and persisting time-series metrics. For situations when a valuable metric is available in the form of an SNMP trap, syslog message, or other event source, OpenNMS can now extract and persist those metrics alongside ones gathered by more traditional methods. Event-sourced data collection bridges data collection and streaming telemetry, enabling extraction of performance metrics from the fault-management domain and presents that metric data as if it had been collected from the performance management components.

Helm 8.0 Release

Grafana dashboards built using OpenNMS Helm 8.0 now incorporate filtering by monitoring location, swapping of ingress and egress flow metrics, and wildcard support to display data more dynamically than before.

ALEC Topology Provider

OpenNMS' Architecture for Learning-Enabled Correlation (ALEC) add-on provides a new way to visualize the correlations it has found. Users can now view correlated situations and their constituent alarms on the topology map, as well as in list form.

Documentation on How to Upgrade OpenNMS

As part of our continuing work to improve the documentation, we created procedures that describe the upgrade process, including pre-upgrade housekeeping tasks, backup guidelines, and a basic upgrade procedure.

Future iterations will include more complex upgrade scenarios. Access this crucial information all in one place, for a smoother experience the next time you upgrade Horizon.

UI Access for Log and Config Files

OpenNMS administrators can now view OpenNMS log files directly from the web UI. In addition, administrators with appropriate permissions can edit OpenNMS configuration files directly from the web UI.

While power users won't be forgetting how to use "tail -f" any time soon, accessing logs and editing config files directly in the UI makes for an easier experience.

Horizon 29

Support for Cortex and improved streaming analytics for flows

Enhancements to Nephron, our streaming analytics plugin for flows, provide improved flow processing, persistence, and performance:

  1. Persist flows to Cortex
  2. Improved Elasticsearch persistence to support batching updates
  3. Streamlined metadata to eliminate redundancy, so less data is stored per update
  4. Better performance when processing large rulesets as a result of updates to the classification engine

Also new in Horizon 29:

Polling and Metadata Improvements

Threshold metadata and the wsman-config.xml file now use stricter error validation when evaluating their respective config files, reducing the likelihood of user error and limiting potential damage that could otherwise occur.

Kafka producer payloads now contain additional useful resource metadata including ID, label, name, index, type, and type label. Resource metadata in producer payloads provides richer information to external systems that consume our feed as part of an integration, and a more complete story about the alarms, metrics, and inventory information from the feed.

You can now optionally persist monitor status to RRD so that it can be retrieved using the Measurements API. Storing the status of a service monitor allows you to query the current status and the status history using the Measurements API.

Run as non-root by default

Reduce required permissions and improve security now that OpenNMS runs by default as the OpenNMS user rather than as root. Running as an unprivileged user significantly mitigates the risk in the event of system compromise.

Location-aware Requisitions from DNS

Configure OpenNMS to create provisioning requisitions from DNS that are associated with a monitoring location.

Administrative users can add a location-aware DNS requisition during provisioning so that imported nodes will have the proper Minion location set.

OpenNMS now monitors itself

OpenNMS now ships with a single node 'localhost' with interface '' to provision a node that represents itself for better OpenNMS metrics.

Add location information to nodes

Use the new GeoIP Provisioning Adapter to enrich a node's asset data with location information. It uses the GeoIP2 Databases from MaxMind to look up longitude/latitude values for a given IP address.

Improved layer-2 network topology with MikroTik LLDP discovery

LLDP discovery with MikroTik devices running RouterOS or Cloud Hosted Router OS enables OpenNMS to discover network links terminated on such devices, which it was previously unable to do. The result is a more complete picture of layer-2 network topology in networks that incorporate these devices.

Horizon 28

Visualize Flows Traffic by Quality of Service (QoS)

Network traffic prioritization is easier when you can visualize flows by QoS. You can quickly verify that your configuration for priority traffic works as specified, and make changes as needed to ensure optimal service performance.

Able to handle up to 300,000 data points per second with flows, and configurable to handle more, OpenNMS processes, aggregates, and exposes this data for improved streaming analytics. OpenNMS’ Helm plugin for Grafana allows you to create flexible dashboards to view this data as time series or tabular views.

Helm now includes options to filter flows traffic by ToS/DSCP (Differentiated Services Code Point). Using the Deep-Dive Flows Dashboard, simply select the DSCP value (or combination of values) from a drop-down list for the QoS you want to visualize (class selector, IP precedence, assured forwarding, expedited forwarding). The ECN (explicit congestion notification) drop-down allows you to further filter on this value to see which flows use ECN-capable transports, and congestion reports for them.

Also new in Horizon 28:

Documentation Migration

We migrated our documentation to the Antora platform, with a new UI and rebrand.

View documentation for all components and plugins in one place, with top-level links to additional help through training videos and community tools like Discourse and Mattermost.

New documentation search functionality allows you to easily find the answers you need.

Location-aware Requisitions from DNS

Configure OpenNMS to create provisioning requisitions from DNS that are associated with a monitoring location.

Administrative users can add a location-aware DNS requisition during provisioning so that imported nodes will have the proper Minion location set.

Brand Refresh

May 12 saw the unveiling of our brand refresh, including our new Open Gyroscope symbol and color palette.

We’ve applied this fresh, updated look across all our projects.

Horizon 27

New: Application Perspective Monitoring

Monitor Digital Experience from Different Perspectives

A key part of OpenNMS’ distributed monitoring solution, Application Perspective Monitoring (APM) monitors the digital experience (DEM) of services and application systems from different perspectives such as geographical locations (countries, regions, buildings) or a cloud application from the client’s viewpoint.

APM integrates seamlessly with our Minion component to monitor your entire network. When a service is not responsive, OpenNMS generates an outage alert that includes the corresponding perspective that identified the outage.

If the New York operations center can see the availability of a service hosted in Houston that is accessed by users in Seattle, you can identify the perspective from which an outage occurs for more effective troubleshooting and network reliability.

Also new in Horizon 27:


Leverage dynamic configuration to use metadata with provisioning, threshold evaluation, and notifications:

Provisioning: persist node, service, and interface metadata to the database during provisioning

Threshold evaluation: streamline threshold creation for single-DS and expression-based thresholds

Notifications: use node-, interface-, and service-level metadata in notifications

gNMI Support for OpenConfig

gNMI and OpenConfig offer a new way to expose data from routers and other tools that vendors are adopting for their devices. OpenNMS connects and establishes a tunnel to these devices, and retrieves and streams metrics every 30 seconds by default. Currently available only on the OpenNMS core, a future release will provide the same feature on Minion.

Vendor support for gNMI includes Juniper, Arista, and Cisco.

Improved Documentation

We have started to restructure the documentation to offer a more task-based approach to using OpenNMS. The Admin Guide includes updated chapters on users and provisioning, while the Installation Guide features a streamlined chapter on installing and configuring a Minion.

Flow Performance Enhancements

Better aggregate flow metrics and enhanced DNS enrichment for improved performance. Aggregate flow queries support resolving hostnames, if available. Sink RPC APIs now expose metrics to Karaf for tracing and performance tuning.

Central Search Functionality

We’ve made it easier to find nodes, KSC reports, and actions in the web UI, with a search bar available on the top of every page.