threshold.declaration_invalid

A threshold in thresholds { } doesn't watch one thing, gives a limit that doesn't apply to it, or gives a value a limit can't take.

Area 16, Built-in services; not declinable; the next step is usually the agent's.

Why Jadpo refuses it

A threshold watches one route, action, query, schedule or subscriber, and each of its limits is an upper bound on something that one thing does. A limit that can't apply, such as the age of the oldest waiting delivery on an action, which has no deliveries, would generate a rule that never fires; a value of the wrong kind has no bound to judge. Thresholds live in a domain's monitoring.jadpo so a reviewer reads every one that watches the domain in one place.

What it looks like

counting gives oldest_waiting:, which only a subscriber's deliveries have:

/// How many visitors have come.type VisitorCount = Int {    min: 0}/// How many visitors have come so far.action count_visitors() -> VisitorCount {    return 1}thresholds {    /// Counting the visitors stays quick.    counting: {        watches: count_visitors        oldest_waiting: 5m    }}

   |15 |         oldest_waiting: 5m   |                         ^^ not for an action

(agent) at the end of the next: line means your coding agent can make the fix itself.

A percentile shorter than a lower one beside it is refused too, since no request could meet it:

/// How many visitors have come.type VisitorCount = Int {    min: 0}/// How many visitors have come so far.action count_visitors() -> VisitorCount {    return 1}thresholds {    /// Counting the visitors stays quick.    counting: {        watches: count_visitors        p50: 80ms        p99: 50ms    }}

   |16 |         p99: 50ms   |              ^^^^ shorter than a lower percentile

How to fix it

If the limit doesn't apply, give one that does. An action's runs have a duration, a share that fails on the server and percentiles:

    counting: {        watches: count_visitors        p99: 50ms    }

counting now judges the action's runs by how long 99% of them take, which the rules made from it alert on.

If the percentiles are the wrong way round, make each higher one at least as long as the one below it:

        p50: 30ms        p99: 50ms

Half the runs must now finish within 30 ms and 99% within 50 ms, which both can.

Related

• Writing a threshold
• Monitoring thresholds