OpenNMS Horizon and Meridian: Monitoring Ledger 2026

Part of the Infrastructure Monitoring Ledger (edition 2026-10-04). How the scores work: methodology.

Snapshot

Tier: Challenger
Owner: The OpenNMS Group, a subsidiary of NantHealth, Inc. since its 2020 acquisition
Licence model: Horizon free under AGPLv3; Meridian LTS by annual subscription in node bands (quote, from about USD 15,000 a year)
Products scored: OpenNMS Horizon 36 and Meridian 2026 with Minion, Sentinel, ALEC and the Helm plugin for Grafana
Latest release: Horizon 36.0.4, 2026-09-09
Next signal: No dated milestone; roadmap themes are gNMI/OpenConfig telemetry, agentic NOC work over MCP and Kubernetes-native Minion and Sentinel
Archetype: Open-source network NOC platform
Evidence grade: B. Release dates match git tags; platform templates (Proxmox, OpenShift Virtualization, DGX) and scale figures are stated without release-note detail and need checking.

Scorecard

Dimension	Score	Direction
Capability today	75.8 / 100	higher is better
Momentum since end of 2022	+0.8 points	higher is better
Credibility	19.5 / 25	higher is better
Commercial risk	10.0 / 25	lower is better
Technical lock-in	9.0 / 25	lower is better
Integrator fit	10.0 / 20	higher is better
AI leverage	11.0 / 20	higher is better
Ledger Index	65.2 / 100	balanced weights

Capability by domain

Scores 0 to 5 against fixed anchors; total is weighted to 100.

Domain (weight)	2016	2019	2022	Today
Server, virtualization and storage (12)	3	3.5	4	3.5
Network monitoring (12)	4	4	4	4
Application and service monitoring (10)	3.5	3.5	3.5	3.5
Data collection and scale (12)	4	4.5	4.5	4.5
Alerting and event management (12)	4	4	4	4
Visualisation and reporting (8)	3	3.5	3.5	3.5
Logs and traces (8)	2.5	2.5	3	3
Automation and remediation (8)	3	3	3.5	3.5
Security and compliance (8)	2.5	3	4	4
New-platform support (VMware exit) (10)	1	1.5	3	4
Total / 100	62.6	67.6	75.0	75.8

Year by year: 2016: 62.6 · 2017: 63.4 · 2018: 63.4 · 2019: 67.6 · 2020: 67.6 · 2021: 68.4 · 2022: 75.0 · 2023: 75.0 · 2024: 74.8 · 2025: 75.8 · 2026: 75.8

What moved the score

Year	Domain	Change	Points	Trigger
2017	Visualisation and reporting	3 → 3.5	+0.8	Horizon 20: Helm plugin GA builds Grafana dashboards from OpenNMS data; Grafana itself is separate
2019	Data collection and scale	4 → 4.5	+1.2	Horizon 25: Kafka bus between core, Minions and Sentinels; active/active Minions; core HA not documented
2019	New-platform support (VMware exit)	1 → 1.5	+1.0	Horizon 25: Kubernetes preview via Prometheus intake; AHV through generic SNMP
2019	Security and compliance	2.5 → 3	+0.8	Horizon 25: mandatory mTLS for Minion RPC; RADIUS and TACACS+; audit logs
2019	Server, virtualization and storage	3 → 3.5	+1.2	Horizon 25: CIM/WBEM ESXi health; IPMI and Redfish sensors for Dell, HPE and Cisco UCS
2021	Security and compliance	3 → 3.5	+0.8	Horizon 28: OpenID Connect and OAuth2 SSO
2022	Automation and remediation	3 → 3.5	+0.8	Horizon 31: cloud requisition sync from AWS and Azure; webhooks to AWX and Rundeck; ITSM via webhooks
2022	Logs and traces	2.5 → 3	+0.8	Horizon 30: OpenSearch 2.x integration; event, trap and syslog search from the console
2022	New-platform support (VMware exit)	1.5 → 3	+3.0	Horizon 31: Nutanix Prism integration discovers AHV clusters, hosts and VMs
2022	Security and compliance	3.5 → 4	+0.8	Horizon 31: SAML 2.0; FIPS 140-2 stated; air-gapped operation; no KEV entry (the security record)
2022	Server, virtualization and storage	3.5 → 4	+1.2	Horizon 31: Nutanix Prism API; Pure, PowerStore and ONTAP packs; Kubernetes via Prometheus scrapes
2024	New-platform support (VMware exit)	3 → 3.5	+1.0	Horizon 33: Proxmox VE template polls nodes, QEMU VMs, LXC and Ceph pools
2024	Server, virtualization and storage	4 → 3.5	-1.2	Horizon 33: Proxmox VE REST template and Nutanix Prism auto-discovery
2025	New-platform support (VMware exit)	3.5 → 4	+1.0	Horizon 34: OpenShift Virtualization pack; AWS and Azure requisitions already in place

Direction, 2023 to 2026

Each item carries one theme and one driver (V vision, C customer need, M market window, U upstream, P portfolio).

Date	Item	Theme	Driver
2023-04	Meridian repackaged into node-band tiers	D12 Packaging and licensing	P
2023-06	Horizon 32: Java 17; Prometheus Remote Write receiver	D4 Collection and scale	U
2023-06	Horizon 32: Kubernetes cluster auto-discovery	D1 Server and virtualization	M
2023-08	Horizon 32.0.2: fix for CVE-2023-38634	D9 Security	C
2024-02	Horizon 33: ML flow classification models	D7 AI-assisted operations	V
2024-02	Horizon 33: Proxmox VE template; Nutanix Prism auto-discovery	D1 Server and virtualization	M
2025-08	Horizon 34: Java 21; ALEC 3.0 root-cause clustering	D7 AI-assisted operations	V
2025-08	Horizon 34: OpenShift Virtualization pack	D1 Server and virtualization	M
2025-12	Horizon 35: official Helm charts; MCP server preview	D10 Automation and remediation	M
2026-05	Horizon 36: MCP server GA; DCGM GPU telemetry	D7 AI-assisted operations	M

Centre of gravity: Server and virtualization (3), AI-assisted operations (3), Packaging and licensing (1)
Driver mix: Vision 20%, Customer need 10%, Market window 50%, Upstream 10%, Portfolio 10%

Credibility: 19.5 / 25

Criterion	Score	Basis
Cadence	3.5	Two or three Horizon majors a year to 2022, then 18 months between Horizon 33 (2024-02) and 34 (2025-08)
Roadmap transparency	4	Public GitHub, docs and issue tracker; direction through blog posts and developer conferences
Say-do	4.5	7 of 7 items since 2023 shipped in the named release, no lag recorded
Velocity	3.5	Several capabilities per major release, slower in 2024-2025
Lifecycle stability	4	Meridian LTS with 3-year support and backported fixes; Java runtime moves handled in-release

Say-do record, 2023 to 2026: 7 items 2023-2026, all shipped: Java 17, Prometheus Remote Write, Proxmox pack, flow ML models, Java 21, Helm charts, MCP server.

Commercial risk: 10.0 / 25 (lower is better)

Criterion	Score	Basis
Price and licence volatility	1.5	Meridian repackaged into Foundation, Advanced and Enterprise node bands in 2023; AGPLv3 unchanged
Purchase constraints	2	Horizon free; Meridian subscription only, quote based, enterprise entry price
Channel and access	2	Open downloads and docs; Meridian repositories behind subscription; no partner programme described
Owner stability	3	Owned since 2020 by NantHealth, a healthcare software company; subsidiary results not reported separately
Cost of staying supported	1.5	Horizon updates free; Meridian keeps 3-year support windows

Security record of the product itself: None found in the KEV catalogue (the security record). CVE-2023-38634 Minion RPC deserialization fixed in Horizon 32.0.2 (2023-08); Log4Shell patched within 72 hours in 2021.

Technical lock-in: 9 / 25 (lower is better)

Criterion	Score	Basis
Formats	2	XML config files and PostgreSQL; metrics in Cassandra, ScyllaDB, TimescaleDB or RRD
Export path	2	Config through ReST API; flows in OpenSearch; no import tools to other products
Stack coupling	2	Java/Karaf core, PostgreSQL required; standard SNMP, flows, gNMI, OpenTelemetry; own Minion
Hardware / cloud coupling	0	Any hardware, fully offline
Skills and tooling coupling	3	OpenNMS XML, requisitions and Karaf skills are specialist and scarce

Integrator fit: 10 / 20

Criterion	Score	Basis
Partner programme openness	2	No partner programme described in the research
Multi-tenancy and self-service	3	Minion locations and surveillance categories used by MSPs; no tenant portal or billing
API and infrastructure-as-code	3	ReST v1 and v2; community Ansible roles; official Helm charts from Horizon 35; no Terraform
Skills and certification	2	No training or certification described in the research

AI leverage: 11 / 20

Strand	Today	Latest step
AIOps on monitoring data	4	2025: Horizon 34: ALEC 3.0 root-cause alarm clustering; DGX and DCGM GPU telemetry
AI platform stack	1	2020: Horizon 26: ALEC ships as a built-in ML module; no natural-language or AI observability service
AI-assisted operations	2	2018: Horizon 22: ML anomaly detection GA; ALEC from 2020 recommends situations; no assistant GA
Agent openness	4	2026: Horizon 36, 2026-05: MCP server GA exposing topology, alarms and metrics

AI say-do: 2 tracked, 2 delivered GA (ALEC 2.0, DGX templates), 0 dropped; MCP moved from preview to GA as promised. AI is unsupervised alarm correlation and anomaly detection.

Reading

OpenNMS is extending a network-first platform with distributed collection, flow processing and ML alarm correlation toward streaming telemetry, new hypervisors and AI agents over MCP. The record shows strong network, event and scale depth and every 2023-2026 promise delivered, but release pace slowed in 2024-2025. Buyers get deep free capability with Horizon, while specialist skills and a small parent company are the main trade-offs.

Open questions and evidence caveats

Owner health: NantHealth's finances are not covered in the research; check before relying on Meridian long term.
Proxmox, OpenShift Virtualization, DGX and FIPS claims lack release-note detail; infra, platforms and security may be high.
No NCM or IPAM; configuration backup needs RANCID or Oxidized.
Core server HA is not documented, which caps the collection score.