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Telemere

Structured telemetry library for Clojure/Script

This library is still under development!!

Telemere is an upcoming next-generation observability toolkit for capturing all kinds of un/structured information in your running Clojure and ClojureScript programs.

It offers a simple, clean, unified API that covers: logging, events, performance measurement, tracing, etc.

Taking full advantage of Clojure's unique macro and interop capabilities, Telemere represents the refinement and culmination of ideas brewing for 10+ years in Timbre, Tufte, Truss, etc.

Latest release/s

• Stable release: coming ~Apr 2024
• v1.0.0-SNAPSHOT (dev): release info (for early adopters)

See here for earlier releases.

Why Telemere?

• Simple, lightweight API that's easy to use, easy to configure, and deeply flexible.
• An unmatched logging experience designed to scale comfortably from the smallest disposable code, to the most massive production applications.
• Easy integration with the tooling of your choice, including first-class out-the-box interop with OpenTelemetry, SLF4J v2, clojure.tools.logging, and Tufte.
• Hyper-optimized and blazing fast, see performance.
• Expressive per-call and per-handler filtering at both runtime and compile-time.
• Easily filter by namespace and id pattern, level, level by namespace pattern, etc.
• Support for auto sampling, rate-limiting, and back-pressure monitoring.
• Support for fully configurable a/sync dispatch (blocking, dropping, sliding, etc.).
• Sensible defaults to make getting started fast and easy.
• Extensive beginner-oriented documentation, docstrings, examples, etc.

Video demo

See for intro and usage: (TODO: coming later)

Quick example

;; TODO: coming later

Observability tips

See here for general advice re: building and maintaining highly observable Clojure/Script systems.

Performance

Telemere is highly optimized and offers terrific performance at any scale:

Compile-time filtering?	Runtime filtering?	Time?	Trace?	nsecs
✓ (elide)	-	-	-	0
-	✓	-	-	200
-	✓	✓	-	280
-	✓	✓	✓	650

Measurements:

• Are ~nanoseconds per signal call (= milliseconds per 1e6 calls)
• Exclude handler runtime (which depends on handler/s, is usually async)
• Taken on a 2020 Macbook Pro M1, running OpenJDK 21

Tip: Telemere offers extensive per-call and per-handler filtering, sampling, and rate-limiting. Use these to ensure that you're not capturing useless/low-value information in production. See here for more tips!

Documentation

• Wiki (getting started, usage, etc.) (TODO: coming later)
• API reference: Codox, clj-doc

Funding

You can help support continued work on this project, thank you!! 🙏

License

Copyright © 2023-2024 Peter Taoussanis.
Licensed under EPL 1.0 (same as Clojure).