Go concurrency · Cloudflare edge
Whimsy's Warden
Keeping watch over everything Whimsy runs.
Whimsy Warden is an availability and latency monitor for production applications and stable beta deployments. It combines a concurrent Go probe engine with scheduled edge checks, a responsive status UI, persistent state, and actionable e-mail alerts.
Monitoring engine
Fast checks without uncontrolled concurrency.
The Go monitor runs target probes through a bounded worker pool. Context cancellation and explicit timeouts prevent a slow service from holding the run open, while connection reuse, redirect limits, and modern TLS defaults keep the HTTP client efficient and deliberate.
A shared declarative target inventory covers both production and stable beta applications. Results are returned in deterministic order, which keeps command-line output, dashboard data, and tests predictable even though the network work happens concurrently.
Operational flow
Probe, persist, decide, notify.
A Cloudflare Worker cron starts a complete check every five minutes.
Targets are checked for availability and response latency.
The latest snapshot and incident state are written to Cloudflare KV.
Cloudflare Email Service reports new outages and latency breaches as they occur.
Useful alerts
E-mail for transitions, not noise.
Warden alerts the Whimsy monitoring inbox when a service goes down or crosses the 500 ms latency threshold. Incident state in KV suppresses duplicates until recovery, so a continuing failure does not create a new message every five minutes.
Purpose-built UI
A control room that reads at a glance.
Status at a glance.
The dependency-free dashboard surfaces healthy and degraded counts, median latency, last-check time, and individual targets. Production and beta filters reduce clutter, while a manual refresh can request a new edge check when an operator needs current evidence. Responsive layouts reorganize the summary, filters, and service cards across wide desktop, tablet, and mobile resolutions so the same operational picture remains useful on a workstation or on the go.
Delivery & isolation
One system, safely separated environments.
One system, safely separated environments.
The UI and API are served at the Cloudflare edge with no-store responses and structured observability logs. Production and beta deploy independently; beta has its own KV namespace and no alerting cron, preventing test traffic from duplicating production incidents.
See it working