Infrastructure monitoring is dominated by open-source tools: Prometheus (metrics), Grafana (visualization), Zabbix (traditional monitoring), and Elastic Stack (log analysis) are the four pillars. Most enterprise monitoring stacks use at least two of these, even alongside commercial tools. The choice depends on whether your infrastructure is traditional (Zabbix), cloud-native (Prometheus), or log-heavy (Elastic).
5 of 15 products in this category match the open source filter and are highlighted below.
Host-based · Cloud / On-prem · Free trial
Available both as a cloud-managed service and as software you run yourself, Checkmk covers estates from a few hundred hosts up to hundreds of thousands. Its auto-discovery engine cuts the initial configuration work that Nagios-derived alternatives demand. Billing is per host. That keeps the number tracking the environment in a way finance can predict as it grows.
Usage-based pricing · Cloud / On-prem · Free trial
Elastic Observability extends the Elastic Stack (Elasticsearch, Kibana, Beats) into infrastructure monitoring with APM and log correlation: strongest for organizations already running Elasticsearch for search or SIEM that want to consolidate observability onto the same data platform without adding another vendor.
Best for: Engineering and operations teams already running the Elastic Stack for search, log analytics, or SIEM that want to add infrastructure monitoring and APM without introducing a new vendor or data platfo
Usage-based pricing · Cloud · Free trial
Grafana Cloud is the managed observability platform built on Prometheus, Loki, and Tempo that gives teams enterprise-grade infrastructure monitoring with the visualization depth Grafana is known for, eliminating the operational burden of self-hosting while preserving open-standards portability that proprietary platforms cannot match.
Best for: DevOps and platform engineering teams that want Prometheus-based infrastructure monitoring with world-class visualization without operating their own Prometheus, Loki, and Tempo clusters. Particularly
Custom quote · On-prem · Free trial
Much of how IT teams think about threshold-based alerting came from Nagios Core, and Nagios XI is its commercial edition. Deployment is on-prem only, the plugin library is strong, and the interface reflects how long the project has been around. Most organizations looking at it now are maintaining an installation they already have.
Open source · Cloud / On-prem · Free trial
No per-host licensing applies, which is where most Zabbix deployments begin. Enterprise and mid-market teams that have the internal capacity to administer it, and a requirement to keep monitoring license costs at zero, find it competitive with PRTG and Nagios XI. Network, server and application monitoring are all covered, hosted or self-managed.
The rest of the infrastructure monitoring tools category, listed because the open source filter above did not select them. Worth reading when the highlighted options do not fit.
Sensor-based · Cloud / On-prem · Free trial
PRTG is an on-premises infrastructure monitoring platform where everything is a sensor (network interfaces, server metrics, cloud services, IoT devices) giving teams granular control over what they monitor and what they pay for, with published pricing and a permanent free tier of 100 sensors.
Host-based · Cloud · Free trial
Collection runs through the Datadog Agent, which reaches cloud, on-prem and container environments, and more than 600 integrations handle the mapping work. Pricing is per host. Mid-market and enterprise teams with mixed infrastructure rarely stop at the infrastructure layer. Pairing it with Datadog APM and logs puts observability behind a single query interface.
Custom quote · Cloud · Free trial
The Davis AI engine correlates symptoms across layers on its own instead of handing analysts raw alert data to connect by hand, which is a meaningful operational difference at enterprise scale. Around it sits full-stack server monitoring software: anomaly detection and automatic dependency mapping spanning cloud, container and on-prem infrastructure, delivered from the cloud on a quoted basis.
Custom quote · Cloud
Teams running genuinely heterogeneous estates are the ones who reach LogicMonitor, because it covers on-prem hardware, network devices, cloud services and containers from one SaaS platform instead of three stitched together. Pricing is quoted, which adds a step to the evaluation, though for a complex estate the breadth usually justifies the call.
Custom quote · Cloud / On-prem · Free trial
Automated discovery builds the topology, threshold-based alerting watches it, and the view spans switching, routing and physical servers together. On-prem deployment on Windows or Linux is what makes OpManager viable for organizations whose data residency requirements rule out cloud-hosted server monitoring software entirely, whatever its feature set.
Usage-based pricing · Cloud · Free trial
The pricing model is the genuine differentiator here. Charging for data ingested and seats used means teams monitoring many hosts at modest data volumes pay less than they would under per-host alternatives, a common pattern in host-heavy estates. High-cardinality environments flip that, and consumption needs careful modeling before any multi-year commitment.
Host-based · Cloud · Free trial
Site24x7 puts servers, websites, networks, and cloud services under one monitoring platform from Zoho's portfolio, with pricing counted by host. At lower scale that predictability is where it competes favorably against Datadog and New Relic, which is why SMB and mid-market teams wanting broad coverage keep it in the running.
Custom quote · On-prem
Deep SNMP coverage across Cisco and other vendors has made NPM a fixture in enterprise and mid-market networks with a lot of switching and routing to watch. Deployment is on-prem only, with Windows server requirements. Organizations moving workloads to the cloud eventually have to decide whether the on-prem monitoring investment stays.
Custom quote · Cloud · Free trial
Splunk Observability Cloud (now part of Cisco) provides real-time streaming infrastructure monitoring with sub-second analytics resolution. Purpose-built for high-cardinality environments where traditional 1-minute polling intervals miss the performance anomalies that cause outages.
Custom quote · Cloud / On-prem
VMware's own stack is the whole scope here, with Aria Operations covering vSphere, NSX, and vSAN through capacity planning, performance analytics, and configuration management. Enterprises running large VMware estates evaluate it for how deeply it reaches into vSphere internals. Monitoring granularity on VMware workloads goes past what general-purpose platforms provide.
Prometheus (metrics collection) + Grafana (visualization) + Alertmanager (alerting) is the CNCF-standard stack for cloud-native. Zabbix provides an all-in-one alternative for traditional infrastructure. The Elastic Stack handles log-based monitoring.
Functionally yes: Prometheus+Grafana replaces Datadog for metrics, Elastic replaces Splunk for logs. The tradeoff is operational staff: commercial tools eliminate infrastructure maintenance, upgrades, and scaling concerns that open-source makes your responsibility.
Budget 0.5-1 FTE for a Prometheus+Grafana stack at 500+ monitored services. Zabbix requires similar effort for database tuning and template management. The cost is real but predictable: unlike usage-based commercial pricing that can spike.
