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 open source tools highlighted below, plus 10 more in this category.
Host-based · Cloud / On-prem · Free trial
Checkmk is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
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
Nagios XI is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
Open source · Cloud / On-prem · Free trial
Zabbix is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
These tools are part of the infrastructure monitoring tools category but may not match the open source filter above. Worth reviewing if the primary options don't 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
Datadog Infrastructure is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
Custom quote · Cloud · Free trial
Dynatrace is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
Custom quote · Cloud
LogicMonitor is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
Custom quote · Cloud / On-prem · Free trial
ManageEngine OpManager is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
Usage-based pricing · Cloud · Free trial
New Relic is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
Host-based · Cloud · Free trial
Site24x7 is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
Custom quote · On-prem
SolarWinds NPM is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
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 Aria Operations is positioned here as a server monitoring software option for teams comparing rollout fit, operating model, pricing structure, and how much administrative effort the product is likely to create after implementation.
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.
