Alarms behave unexpectedly – Hermetry

Эта страница перечисляет наиболее частые причины неожиданного поведения тревог с быстрой проверкой для каждой. Полное руководство: Устранение неполадок с правилами и тревогами; проблемы с уведомлениями описаны в Устранение неполадок с уведомлениями.

The eight most common causes

#	Cause	Symptom	Quick check and fix
1	The data is not stored	No alarm, and the device’s Telemetry tab is empty or old	Fix the data first: Data does not arrive
2	The root flow does not evaluate alarm rules	Data is stored, but no rule ever fires for this profile	The device’s root flow (the profile’s own, or the organisation’s) must contain the Alarm rules block before saving. See Hosts, the root flow and profile root flows.
3	The key does not match	The rule list marks Unknown key	Keys are case-sensitive: `Temperature` is not `temperature`. Match the key on the Telemetry tab.
4	The threshold attribute is missing	One device never alarms, others do	A rule that compares with `{ "attribute": … }` does not check a device without that attribute. Set it on the device’s Attributes tab.
5	The value is text	`>` or `<` never true	Comparisons on text that is not a number are always false. Send numbers.
6	Debounce cannot be reached	The alarm opens much later than expected, or never	With Seconds (device time), time only advances when readings arrive. A device that reports every 10 minutes needs at least two true readings.
7	The value hovers at the threshold	The alarm opens and clears again and again, or is marked Flapping	Add hysteresis or debounce by readings. See Debounce, hysteresis and dampening.
8	The device stopped sending the rule’s key	The alarm never clears	Messages without the rule’s keys are not samples. Clear it by hand, and add an offline rule. See Offline alarms.

An alarm opened but nobody was told

Check	Detail
The rule has a `notify` block	Without it nobody is told. See Alarm notifications in depth.
The severity reaches `minSeverity`	A Warning alarm does not reach a block set to Major and up
The device is muted	The timeline says Muted: nobody was notified. See Muting a device for maintenance.
The alarm is Backfilled	Alarms from late readings tell nobody about the past; an alarm still open when live data returns is announced then
You expected e-mail or SMS	Alarm rules send e-mail only to `email` recipients and send no SMS. Members and roles are reached in the bell, by push where it is set up and in linked chat apps.
Push reaches nobody	Registering a browser for push is in development. See Browser push.

An alarm behaves differently than you designed

Behaviour	Explanation
The alarm cleared by itself while nobody acknowledged it	Alarms resolve automatically when the condition clears. There is no “must acknowledge before clear” (latching) option. Review resolved alarms whose Acknowledged column is empty.
A lower severity did not notify	A severity fall, an acknowledgement or a repeat at the same severity notifies nobody; a rise does
A second alarm of the same type did not open	One active alarm per device and type; repeats are counted as occurrences
An alarm opened again right after you cleared it	After a clear by hand the rule waits until the condition has been false once. A new alarm means the condition went false and true again, or a flow raised it. Check the timeline.
An alarm raised by a flow or a Rules-card rule never clears	Such alarms have no condition; only a clear action, a flow or a person clears them
Nobody was paged again while the alarm stayed open	Reminders need `repeatEverySec` in the rule’s notify block (60 seconds to 7 days)
Unacknowledged alarms did not escalate to someone else	There is no on-call rotation for IoT alarms. Use reminders and a severity rise, or a flow.
The rule switched off but its alarms stay open	Clear them by hand or switch the rule back on

An alarm rule cannot be saved

Message	Fix
“A key names a telemetry key: no spaces and not a number.”	Put the value in Value, not in Key
“Another rule of this profile has this type.”	Types are unique per profile
“Between 10 seconds and 7 days.”	The offline delay is out of range
“The alarm rules changed at the same time; try again.”	Reload and save again
A permission error	Editing alarm rules needs Edit the alarm rules of device profiles (Admin by default)

Who may do what

Action	Default role
View alarms and rules	User
Acknowledge and add notes	User
Clear by hand, mute devices, edit rules	Admin

See Alarms and Permissions reference.