cake-stats

cake-stats

Real-time web UI for monitoring CAKE SQM (Smart Queue Management) statistics on Linux/OpenWrt routers.

Table of Contents

• How it looks like
  • Desktop
  • Mobile
• Status
• Features
• Requirements
• Build
• Usage
• Design Notes
• Limitations & Next Steps
• Contributing
• License

How it looks like

Desktop

UI for desktop screens

Graphs for desktop screens

Mobile

UI for mobile screens

Graphs for mobile screens

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Status

• Stable — all parser unit tests passing, binary builds clean for 14 target platforms.

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Features

• Automatically discovers all CAKE qdiscs via tc -s qdisc
• Parses every CAKE field: thresh, target, interval, pk_delay, av_delay, sp_delay, backlog, pkts, bytes, way_inds, way_miss, way_cols, drops, marks, ack_drop, sp_flows, bk_flows, un_flows, max_len, quantum
• Correctly handles diffserv modes: diffserv3, diffserv4, diffserv8, besteffort, precedence; also parses the separate fwmark MASK tin-override parameter
• Two-word tier names are joined correctly (e.g. "Best Effort")
• Real-time push via Server-Sent Events — no WebSocket, no polling jitter
• Single static binary — no runtime dependencies; runs on OpenWrt with ≈4 MB of RAM overhead
• Web UI: dark TUI aesthetic (#2D3C59 bg, JetBrains Mono, zero hover animations)
• Responsive for desktop and mobile (sticky first column, horizontal scroll on small screens)
• Per-interface live sparklines (TX throughput, avg latency, drops/s) with current-value labels
• Tap/click any sparkline bar to open a full-screen history modal with three uPlot time-series charts
• Server-side ring buffer retains history across page reloads (configurable via -history flag)

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Requirements

• Linux kernel with tc + sch_cake module loaded, or OpenWrt with kmod-sched-cake
• Go 1.22+ (build only; not needed at runtime)

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Build

git clone https://github.com/galpt/cake-stats
cd cake-stats
go test ./...          # should print PASS
go build -o cake-stats .

Cross-compile for a MIPS OpenWrt router:

CGO_ENABLED=0 GOOS=linux GOARCH=mips GOMIPS=softfloat \
  go build -ldflags "-s -w" -o cake-stats-linux-mips .

Pre-built binaries for all common platforms are attached to every GitHub Release.

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Usage

Quick start

./cake-stats                 # serves on http://0.0.0.0:11112
./cake-stats -port 8080      # custom port
./cake-stats -interval 2s    # poll tc every 2 seconds (default 1s)
./cake-stats -history 3600   # retain 1 hour of history (default 300 = 5 min)
./cake-stats -host 127.0.0.1 # listen only on loopback
./cake-stats -version        # print version and exit

Open http://<router-ip>:11112 in a browser.

Install on OpenWrt

sh install.sh                # auto-detects arch, downloads latest binary
sh install.sh --port 11112 --interval 1s

Install on systemd Linux

sudo sh install.sh

Uninstall

sh uninstall.sh              # prompts for confirmation
sh uninstall.sh --force      # no prompts

API

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Design Notes

• Pure stdlib Go: no external dependencies; the binary embeds index.html via //go:embed.
• SSE over WebSocket: server-to-client only push makes SSE sufficient and simpler; browsers handle automatic reconnection.
• uint64 for all counters: avoids overflow for high-throughput links; max ~18.4 EB.
• sync.RWMutex: a single reader/writer lock separates the poller goroutine from concurrent HTTP handlers.
• Delay fields as strings: pk_delay, av_delay, sp_delay are kept as raw strings (e.g., "6.73ms") so the unit suffix is preserved.
• Ring-buffer history: HistoryStore allocates a fixed-size ring per interface at startup; memory is bounded by capacity × interfaces × ~40 B and never grows. Configurable via -history N (default 300 samples ≈ 5 min at 1 s interval).
• Sparklines: pure SVG polylines drawn in-place inside stable DOM nodes so the per-second innerHTML swap of the stats table does not affect them. uPlot (CDN) is used only for the full-screen history modal.

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Limitations & Next Steps

• No authentication; if exposing to the internet, put behind a reverse proxy with basic auth.
• Windows/FreeBSD builds are provided but CAKE is a Linux-only qdisc.

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Contributing

go test ./...    # run unit tests
go vet ./...     # static analysis

PRs welcome. Please keep external dependencies at zero.

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License

MIT

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