Apache SkyWalking vs Skylight

Apache SkyWalking is a free, self-hosted observability platform for cloud-native systems and AI workloads. It brings traces, metrics, logs, and profiling together to help users explore services, Kubernetes, and infrastructure through topology, telemetry, profiles, and alerts. For AI workloads, users can inspect model and MCP call latency and token rates, and review agent conversations, tool calls, and recorded file changes. The project lists agents for Java, Python, NodeJS, Go, Rust, PHP, Ruby, Nginx LUA, Kong, and client-side JavaScript. Its integrations and ecosystem include OpenTelemetry OTLP, Istio, Envoy, Kubernetes, Grafana, and MCP. BanyanDB is described as a database for ingesting, analyzing, and storing observability data. Docker installation instructions cover Linux, macOS, WSL, and Windows PowerShell. Horizon UI supports SkyWalking natively since v11 and partially for v10. Its security documentation covers Content-Security-Policy, strict session cookies, no-store API responses, and optional login auditing. Apache source releases are official artifacts, with PGP or SHA512 verification recommended; the GraalVM distribution is marked experimental.

Skylight is a cloud profiler for Ruby and Rails applications, available through API, Linux, macOS, and web platforms. It ranks endpoints by “agony,” combining popularity with response time, and plots deployments against performance so teams can relate code changes to results. Supported Ruby frameworks include Rails, Sinatra, and Grape. Skylight analyzes Sidekiq, DelayedJob, and ActiveJob background queues, and can flag allocation-heavy code and repeated queries. Endpoint timelines present aggregated, sanitized SQL queries. GraphQL queries are grouped by name in the dashboard and endpoint event sequences. A weekly report identifies improved endpoints, slowdown warnings, and endpoints that declined over six weeks. Each account includes 100,000 free traces per month. Paid tiers start at $20 a month and adjust to monthly trace volume across apps. A 30-day trial is available without a credit card. Open-source apps may apply for free public reporting. Communications are encrypted, and access to customer information is limited to selected personnel and contractors.