go-zero is a full-stack Go microservices framework with an integrated code generation toolchain (goctl). In production, it provides a production-grade HTTP/REST server (rest/) with a middleware chain for authentication, tracing, rate limiting, circuit breaking, and load shedding; a gRPC server/client framework (zrpc/) with interceptors for observability, auth, and timeout; an API gateway (gateway/) that translates HTTP requests to gRPC; and a CLI tool (goctl) that generates Go, TypeScript, Dart, Java, and Swagger code from API definitions, SQL schemas, and protobuf files. The core library (core/) delivers building blocks: configuration loading (YAML/JSON/TOML), structured logging with rotation, Prometheus metrics, OpenTelemetry tracing, circuit breaker (Google SRE algorithm), adaptive load shedding, rate limiting (token bucket, period limit), distributed caching (Redis, in-memory), SQL/NoSQL data access with caching, service discovery (etcd, Kubernetes), concurrency primitives (singleflight, mapreduce, stream processing), and data structures (rolling window, timing wheel, safe map). The architecture is modular, with each package providing clean interfaces and option patterns. The codebase is well-tested, actively maintained, and demonstrates strong engineering craftsmanship.
The sentry-ruby repository is the official SDK for Ruby, designed for error tracking, performance monitoring, and distributed tracing. It functions as an instrumentation layer that captures exceptions, transactions, logs, and metrics from Ruby applications and transmits them to the Sentry backend. The architecture follows a Hub/Scope/Client pattern, ensuring thread and fiber isolation for context management across concurrent requests. It supports a wide range of integrations including Rails, Sidekiq, Resque, and OpenTelemetry, making it a central piece of observability infrastructure for the Ruby ecosystem. The SDK manages the full lifecycle of telemetry data, from capture to transport. It implements sophisticated sampling logic to maintain consistent sampling rates across distributed services using deterministic algorithms. The transport layer handles rate limiting, compression, and envelope serialization, ensuring efficient communication with the Sentry server. The codebase is structured as a monorepo with a core gem (sentry-ruby) and modular integrations (sentry-rails, sentry-sidekiq, etc.), allowing for targeted updates and version compatibility testing across multiple Ruby and framework versions. Data flows from the application through the SDK's Scope and Client, where events are processed, sampled, and buffered before being sent via HTTP or Spotlight. The system supports structured logging and metrics collection, adhering to the Sentry Logs Protocol. It includes robust testing infrastructure with matrix testing across Ruby versions (2.7-4.0) and framework versions (Rails 5.2-8.1.3), ensuring stability and compatibility. The SDK is actively maintained with recent commits and issue triage, reflecting its critical role in production environments.
Apache SkyWalking is an open-source APM (Application Performance Monitoring) system designed for microservices, cloud-native, and container-based architectures. It provides distributed tracing, metrics aggregation, log analysis, and profiling capabilities (including eBPF, async-profiler, and JFR). The system features a modular, plugin-based architecture where receivers ingest telemetry data, analyzers process it, storage plugins persist it, and query services expose it via GraphQL, PromQL, LogQL, and TraceQL interfaces. Alarm mechanisms detect anomalies and trigger notifications through multiple channels. The codebase demonstrates strong engineering practices with clear separation of concerns, extensive use of interfaces and dependency injection, and reusable patterns like the module system, storage abstraction, and analysis listener framework.
This repository provides TransmittableThreadLocal (TTL), a Java library that extends InheritableThreadLocal to propagate thread-local values across threads even when using thread pools, executors, ForkJoinPool, and other asynchronous constructs. It solves the common problem of context loss (e.g., tracing, security, session) in asynchronous Java applications. The library offers three usage modes: manual wrapping of Runnable/Callable via TtlRunnable/TtlCallable, wrapping executors via TtlExecutors, and transparent bytecode transformation via a Java Agent (TtlAgent) that automatically instruments JDK thread pool classes. The architecture is modular: ttl-core contains the core API and CRR (Capture-Replay-Restore) pattern, ttl-agent provides the agent with Javassist-based transformlets, ttl-kotlin adds Kotlin extensions, and ttl-integrations includes Vert.x 3/4 support. A ttl2-compatible module maintains backward compatibility with the v2 API. The library is widely adopted in the Java ecosystem (e.g., Apache ShardingSphere, SOFARPC) and is under active development with a v3 branch introducing a refined API. While primarily a library, it includes a Java Agent component that operates at the JVM level, making it a hybrid of library and instrumentation tool.
This repository implements OpenTelemetry eBPF Instrumentation (OBI), a production-grade observability agent that uses eBPF to automatically capture distributed traces, metrics, and logs from user-space applications without any code changes. It supports a wide range of protocols (HTTP/1.1, HTTP/2, gRPC, SQL, Redis, Kafka, MongoDB, AMQP, MQTT, DNS, and more) and multiple language runtimes (Go, Java, Python, Node.js, Ruby, .NET, Rust). The agent can run as a standalone binary, a Docker container, or an OpenTelemetry Collector receiver. Its architecture consists of eBPF programs (kprobes, uprobes, tracepoints, TC) that emit events to ring buffers, which are read by Go userspace tracers and processed through a pipeline of discovery, decoration, filtering, and export stages. Telemetry is exported via OTLP (gRPC/HTTP) or Prometheus, with optional Kubernetes metadata enrichment and network flow monitoring. The codebase is well-structured with clear separation of concerns, extensive integration tests, and several reusable generic components (message queues, pipeline runners, expiry caches, attribute filters). It is actively maintained with frequent commits and comprehensive CI/CD.
This repository is a comprehensive personal R&D platform implementing a polyglot microservices architecture. It hosts a personal website/web application (React/Vite), multiple API servers in different languages (Rust/Axum, Go/Gin/gRPC, Python/FastAPI, Node.js/Express), mobile applications (iOS/Android/React Native), and desktop applications (Qt). The platform includes extensive data processing infrastructure (Kafka, Pulsar, NATS, Spark, Flink), machine learning capabilities (model training/serving/fine-tuning), monitoring and observability tools, and infrastructure as code (Terraform/OpenTofu, Kubernetes). Services communicate via messaging systems and APIs, with a clear separation of concerns and standardized patterns for configuration, health checks, logging, and error handling across language implementations.
SigNoz is a full-stack open-source observability platform that ingests OpenTelemetry data (traces, metrics, logs), stores it in ClickHouse, and provides a rich web UI for querying, dashboards, alerts, and infrastructure monitoring. The backend is written in Go with a modular architecture using factory/provider patterns, SQL migrations, and OpenFGA-based authorization. The frontend is a React/TypeScript SPA with Zustand state management, react-query, uPlot charts, and a comprehensive query builder supporting PromQL, ClickHouse SQL, and builder queries. The enterprise edition adds anomaly detection, RBAC, licensing, and usage metering. The codebase is actively maintained with extensive testing (unit, integration, e2e) and CI/CD, though some legacy API versions and deprecated clients indicate ongoing migration.
This repository contains the Apache SkyWalking Nginx Agent, a Lua-based library that provides distributed tracing capabilities for Nginx and OpenResty deployments. The agent integrates with Nginx's Lua API to automatically trace incoming and outgoing HTTP requests, propagate trace context between services using custom headers (sw8 and sw8-correlation), and report trace data to a SkyWalking OAP server. The architecture uses Nginx's phased execution model (init_worker, rewrite, body_filter, log) to manage the tracing lifecycle, with a shared dictionary for buffering trace segments and a timer for periodic reporting and heartbeats. The codebase demonstrates strong engineering practices with clear separation of concerns, comprehensive error handling, and performance optimizations like table pooling to reduce garbage collection pressure in LuaJIT. Several components show particular craftsmanship and reusability: the utility module provides high-performance table pooling and ID generation; the correlation context module implements lightweight context propagation via base64-encoded headers; and the segment reference module handles trace context serialization for cross-process tracing.
This repository is a curated list of OpenTelemetry resources, maintained as a static markdown file (readme.md). It serves as a reference for developers and engineers seeking to learn about OpenTelemetry, including books, videos, blogs, instrumentation guides, and vendor solutions. The repository does not contain any executable code or data processing logic; instead, it organizes external links into thematic sections for easy consumption. The project is actively maintained, with recent commits and community engagement (as indicated by stars, forks, and open issues). It follows standard open-source practices with a license, code of conduct, and contributing guidelines. Technically, there is no drift to assess as the repository consists solely of documentation and configuration files without external dependencies. While the repository lacks reusable software components, its value lies in the curation and presentation of OpenTelemetry knowledge. The markdown structure is clean and navigable, making it a useful starting point for anyone exploring the OpenTelemetry ecosystem.
Stan's Robot Shop is a polyglot microservice application designed as a sandbox for learning container orchestration and monitoring. The system comprises eight services (user, catalogue, cart, payment, shipping, ratings, dispatch, web) each built with a different technology stack (Node.js, Java, Python, Go, PHP) and communicating via HTTP or RabbitMQ. Data is persisted in MongoDB (catalogue, user), Redis (cart, session), and MySQL (shipping, ratings). The application provides Docker Compose and Kubernetes manifests for deployment, along with Instana integration for automatic tracing and metrics collection. While the application successfully demonstrates microservice patterns and technology diversity, the codebase exhibits significant technical drift due to outdated dependencies (e.g., Express 4.15, Redis 2.8, Spring Boot 2.3) and lacks modern practices such as comprehensive error handling and security measures. The architecture is modular and service boundaries are clear, but the implementation relies on boilerplate for tracing and health checks. A notable reusable component is the Haversine distance calculator in the shipping service, which is isolated and dependency-free.