How long until a missed heartbeat is flagged? A reproducible detection timing table

Description and use

Determined exact time until a missed heartbeat is flagged late or down using detector source code and a timing table.

Problem

Determine how long a scheduled workflow can miss a heartbeat before a monitor marks it late or down.

Outcome

The detector checks every 60 s, marks a workflow late after 1.5× its expected interval and down after 2×. The table shows exact observed ranges and p95 values for 1, 5, 10, 30, 60 min heartbeats.

Workflow

• Extract detector source to read check interval and status multipliers.
• Enumerate every whole‑second scheduler phase (1–60s) for each example interval.
• Record earliest, median, p95, and latest transition times for late and down states.
• Generate a fingerprint of the repository commit, source path, dirty state, and SHA‑256 of the tested implementation.
• Publish the timing table and associated dataset.
• Use the table to set realistic alert thresholds.
• Optionally use the free cron expression explainer to schedule workflows.

Evidence

The detector checks every 60 seconds, marks a workflow late after 1.5 times its expected interval and down after 2 times its expected interval.

Source

Implementation rule: late when elapsed > expected × 1.5, down when elapsed > expected × 2, evaluation every 60 s.

Source

The generator reads the current detector source and extracts its check interval and status multipliers.

Source

The output stores the repository commit, source path, dirty state and SHA-256 of the tested implementation (source SHA-256 d1ff53f470a80addc76384515fca0e17567588e44c550b903f7bc01ae1940321).

Source