http-latency-prober/CHANGELOG.md

Changelog

All completed features are logged here in reverse-chronological order.

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2026-07-01 00:08 — JSON output flag (Go, Step 4)

• --json flag emits a JSON array with one entry per URL
• Schema always uses min/avg/max shape (consistent regardless of -n)
• Phases absent from the request (e.g. TLS on HTTP) are omitted from the JSON object
• Failed URLs are excluded from JSON output and reported to stderr
• Text output unchanged and remains the default

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2026-07-01 00:08 — Multiple URLs + sampling (Go, Step 3)

• -n/--count flag repeats each URL N times and reports min/avg/max per phase
• probe.Summarize aggregates a slice of Results into per-phase PhaseStats
• Multi-sample output shows an aligned min/avg/max table with a header row
• Single-sample output (n=1) is unchanged from Step 2

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2026-07-01 00:08 — Per-phase breakdown (Go, Step 2)

• Instrumented requests with net/http/httptrace.ClientTrace
• DNS lookup, TCP connect, TLS handshake, Server/TTFB, Transfer, Total phases
• TLS row omitted automatically for plain http:// URLs
• Aligned text output with separator before Total

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2026-07-01 00:08 — Simple total latency (Go, Step 1)

• probe.Measure performs an HTTP GET and records wall-clock total time
• main.go prints URL, HTTP status code, and total duration for each URL
• Exits with code 1 if any URL fails
• Multiple URLs accepted as positional arguments

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2026-07-01 00:08 — Project scaffold (Go, Step 0)

• Created project structure: go/, python/, docs/plans/, docs/usage/
• Initialised Go module latprobe (go/go.mod)
• Minimal go/main.go that prints usage and exits cleanly when no URL is given
• Stub go/internal/probe/probe.go defining the Result type and Measure signature
• Foundation files: README.md, CLAUDE.md, CHANGELOG.md
• Saved initial plan to docs/plans/2026-07-01-00-08-go-latency-tool.md