Apache SkyWalking
Apache APM platform for service topology, distributed tracing, metrics, logs, and cloud-native diagnostics.
Metrics
Checkmk Raw
Nagios-descended infrastructure monitoring with auto-discovery, pre-built service checks, and a polished web UI. Raw edition is GPL-2.0.
Fluent Bit
CNCF graduated lightweight log/metric forwarder. The default in-cluster log shipper for Kubernetes.
Grafana
The de-facto open-source dashboard layer. Plug into Prometheus, Loki, Tempo, InfluxDB — one pane of glass.
Grafana Mimir
Grafana Labs' horizontally scalable, multi-tenant Prometheus-compatible long-term metrics store.
Netdata
Real-time per-second metrics with instant auto-discovery. Dashboards out-of-box, zero config.
OpenObserve
Rust-based, columnar, object-storage-backed. Claims 140x lower storage cost than Elasticsearch for logs.
OpenTelemetry Collector
Vendor-neutral telemetry collector for receiving, processing, and exporting traces, metrics, and logs.
Perses
CNCF dashboarding tool with dashboards-as-code, static validation, and Kubernetes-native workflows. A GitOps-friendly Grafana alternative.
Prometheus
The CNCF-graduated, pull-based metrics store. Industry default for self-hosted metrics.
SigNoz
Full-stack, OpenTelemetry-native APM + logs + metrics. The closest single-tool Datadog alternative.
Thanos
CNCF-graduated long-term storage and global query layer for Prometheus, backed by object storage.
Uptrace
OpenTelemetry APM backed by ClickHouse. Lean alternative to SigNoz.
Vector
High-performance observability data pipeline. Sources, transforms, sinks — written in Rust by Datadog (open source).
VictoriaMetrics
Prometheus-compatible TSDB optimized for ingestion rate and storage cost. Single-binary by default, cluster mode for scale.
Zabbix
Classic agent-based monitoring suite for hosts, networks, and services. Pre-Prometheus old guard, still actively developed.