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Open-Source Observability · AppMetrics

AppMetrics

App Metrics is an open-source .NET library that records application performance metrics (requests, timers, gauges, counters) and sends them to external systems like InfluxDB, Prometheus, or Graphite. It provides in-memory aggregation and sampling to minimize overhead while supporting visualization through Grafana dashboards.

Source: GitHub — github.com/AppMetrics/AppMetrics
2.2k
GitHub stars
292
Forks
C#
Primary language
Apache-2.0
License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

FieldValue
RepositoryAppMetrics/AppMetrics
OwnerAppMetrics
Primary languageC#
LicenseApache-2.0 — OSI-approved
Stars2.2k
Forks292
Open issues111
Latest release4.2.0 (2021-04-15)
Last updated2025-07-23
Sourcehttps://github.com/AppMetrics/AppMetrics

What AppMetrics is

Cross-platform .NET/C# metrics instrumentation library using multiple reservoir sampling algorithms (Exponentially Forward Decaying, Sliding Window, Algorithm R). Abstracts metric destinations via pluggable reporters and provides metric types including Gauges, Counters, Meters, Histograms, Timers, and Apdex scores. Integrates with monitoring backends and includes BenchmarkDotNet-based performance testing.

Quickstart

Get the AppMetrics source

Clone the repository and explore it locally.

terminalbash
git clone https://github.com/AppMetrics/AppMetrics.gitcd AppMetrics# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

ASP.NET Core Application Monitoring

Native .NET integration for web application metrics (request rates, latency, error counts) with pre-built Grafana dashboards and Prometheus/InfluxDB export.

Performance-Sensitive Microservices

In-memory metric aggregation and configurable flush intervals minimize per-request overhead while maintaining detailed observability for distributed systems.

Multi-Backend Monitoring Strategy

Metric abstraction layer allows switching between InfluxDB, Prometheus, Graphite, and other backends without application code changes.

Implementation considerations

  • Requires integration with external metric storage (InfluxDB, Prometheus, Graphite); standalone operation not supported.
  • In-memory buffering and configurable flush intervals trade latency for reduced I/O; tuning needed per workload.
  • Documentation references separate Hugo-based docs repository; ensure version alignment with release being deployed.
  • Dependency on .NET Core 2.x SDK minimum (per build instructions); verify runtime compatibility with target environment.
  • Custom reservoir implementations present; review sampling algorithm choice (Forward Decaying, Sliding Window, Algorithm R) for metric accuracy needs.

When to avoid it — and what to weigh

  • Requiring Recent Active Development — Latest release (4.2.0) is from April 2021; last push July 2025 suggests maintenance mode. 111 open issues indicate backlog not being actively cleared.
  • Non-.NET Technology Stack — C# / .NET Core / .NET Framework only. Not viable for Java, Python, Go, or other ecosystems.
  • Need for Real-Time Streaming Metrics — Architecture uses in-memory batching and interval-based flushing; not designed for sub-second real-time streaming scenarios.
  • High-Volume, Mission-Critical Metrics — No benchmark data provided showing performance under extreme load; open issue count and stale release suggest unresolved production concerns.

License & commercial use

Apache License 2.0 (Apache-2.0). Permissive OSI-approved open-source license allowing modification, distribution, and private use. Derived from Metrics.NET (Apache 2.0) and Dropwizard Metrics (Apache 2.0).

Apache 2.0 is a permissive open-source license that explicitly permits commercial use, modification, and distribution. No restriction on proprietary derivative works. License does not grant trademark rights or warranty. Standard commercial use is allowed; consult legal if integrating modified code into proprietary products or redistributing.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

SignalAssessment
MaintenanceModerate
DocumentationAdequate
License clarityClear
Deployment complexityLow
DEV.co fitGood
Assessment confidenceMedium
Security considerations

No security audit results, vulnerability disclosures, or hardening measures documented. In-memory metric storage during buffering has no encryption at rest. Network communication to backend (InfluxDB, Prometheus) security dependent on transport layer (HTTPS, authentication) configuration. Stale release (4+ years) may indicate unpatched dependencies; review dependency tree before production use. No claim of security certification or penetration testing results provided.

Alternatives to consider

Prometheus client libraries (.NET)

Newer, actively maintained, industry standard for cloud-native monitoring. Direct Prometheus scrape model versus App Metrics abstraction.

OpenTelemetry (.NET SDK)

Modern observability standard (metrics, traces, logs) with vendor-agnostic backend support. Actively developed by CNCF; recommended for new projects.

Application Insights (Azure)

Proprietary Microsoft service with native .NET integration, full APM features, and managed infrastructure; simpler setup but vendor lock-in.

Software development agency

Build on AppMetrics with DEV.co software developers

Evaluate App Metrics' fit for your monitoring strategy. Verify backend compatibility, review stale release status, and assess OpenTelemetry alternatives for new projects.

Talk to DEV.co

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AppMetrics FAQ

Does App Metrics support .NET Framework or only .NET Core?
Both. App Metrics targets .NET Core, .NET Framework, and .NET Standard, making it compatible with legacy and modern .NET applications.
What happens to metrics if the backend is temporarily unreachable?
Not explicitly documented. In-memory buffering should queue metrics until flush succeeds; behavior during prolonged outages requires code review or vendor clarification.
Can I switch metric backends without changing application code?
Yes. App Metrics abstracts the reporting layer. Swapping InfluxDB reporter for Prometheus requires configuration change only, not code refactoring.
Is App Metrics production-ready?
Uncertain. Stable API and 2249 GitHub stars suggest adoption, but stale release (April 2021) and 111 open issues raise concerns. Requires vendor evaluation before mission-critical deployment.

Work with a software development agency

Adopting AppMetrics is usually one piece of a larger software development effort. As a software development agency, DEV.co provides software development services and web development expertise — pairing senior software developers and web developers with your team to design, build, and operate open-source observability software in production.

Ready to instrument your .NET application?

Evaluate App Metrics' fit for your monitoring strategy. Verify backend compatibility, review stale release status, and assess OpenTelemetry alternatives for new projects.