Heartbeat Monitor

Heartbeat monitors are push-based: your job calls a URL, and Kener measures how long it has been since the last signal.

Heartbeat endpoint

URL format:

/ext/heartbeat/{tag}/{secret}

Accepted methods: GET and POST.

Older heartbeat URLs used a colon — /ext/heartbeat/{tag}:{secret}. Those still work; they are rewritten to the path-separated form automatically, so existing cron jobs need no changes.

Minimum setup

Set:

• degradedRemainingMinutes (default 5)
• downRemainingMinutes (default 10)

downRemainingMinutes must be greater than degradedRemainingMinutes.

Status logic

If no heartbeat has ever been received:

• status is NO_DATA

Otherwise let diff = elapsed time since last heartbeat:

• diff > downRemainingMinutes → DOWN
• diff > degradedRemainingMinutes → DEGRADED
• otherwise → UP

Latency is recorded as elapsed time since the last heartbeat (ms).

Example

{
    "type": "HEARTBEAT",
    "type_data": {
        "degradedRemainingMinutes": 5,
        "downRemainingMinutes": 10
    }
}

Minimal cron usage pattern:

*/5 * * * * /path/to/job.sh && curl -s "https://your-kener-host/ext/heartbeat/my-job/my-secret"

Troubleshooting

• Always NO_DATA: endpoint never called or wrong tag/secret
• Always DOWN/DEGRADED: thresholds too low for actual job interval
• Signal accepted but stale: ensure heartbeat is sent only after successful completion