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diff --git a/docs/monitor/configure-alarms.md b/docs/monitor/configure-alarms.md new file mode 100644 index 0000000..2a97795 --- /dev/null +++ b/docs/monitor/configure-alarms.md @@ -0,0 +1,148 @@ +<!-- +title: "Configure health alarms" +description: "Netdata's health monitoring watchdog is incredibly adaptable to your infrastructure's unique needs, with configurable health alarms." +custom_edit_url: https://github.com/netdata/netdata/edit/master/docs/monitor/configure-alarms.md +--> + +# Configure health alarms + +Netdata's health watchdog is highly configurable, with support for dynamic thresholds, hysteresis, alarm templates, and +more. You can tweak any of the existing alarms based on your infrastructure's topology or specific monitoring needs, or +create new entities. + +You can use health alarms in conjunction with any of Netdata's [collectors](/docs/collect/how-collectors-work.md) (see +the [supported collector list](/collectors/COLLECTORS.md)) to monitor the health of your systems, containers, and +applications in real time. + +While you can see active alarms both on the local dashboard and Netdata Cloud, all health alarms are configured _per +node_ via individual Netdata Agents. If you want to deploy a new alarm across your +[infrastructure](/docs/quickstart/infrastructure.md), you must configure each node with the same health configuration +files. + +## Edit health configuration files + +All of Netdata's [health configuration files](/health/REFERENCE.md#health-configuration-files) are in Netdata's config +directory, inside the `health.d/` directory. Navigate to your [Netdata config directory](/docs/configure/nodes.md) and +use `edit-config` to make changes to any of these files. + +For example, to edit the `cpu.conf` health configuration file, run: + +```bash +sudo ./edit-config health.d/cpu.conf +``` + +Each health configuration file contains one or more health _entities_, which always begin with `alarm:` or `template:`. +For example, here is the first health entity in `health.d/cpu.conf`: + +```yaml +template: 10min_cpu_usage + on: system.cpu + os: linux + hosts: * + lookup: average -10m unaligned of user,system,softirq,irq,guest + units: % + every: 1m + warn: $this > (($status >= $WARNING) ? (75) : (85)) + crit: $this > (($status == $CRITICAL) ? (85) : (95)) + delay: down 15m multiplier 1.5 max 1h + info: average cpu utilization for the last 10 minutes (excluding iowait, nice and steal) + to: sysadmin +``` + +To tune this alarm to trigger warning and critical alarms at a lower CPU utilization, change the `warn` and `crit` lines +to the values of your choosing. For example: + +```yaml + warn: $this > (($status >= $WARNING) ? (60) : (75)) + crit: $this > (($status == $CRITICAL) ? (75) : (85)) +``` + +Save the file and [reload Netdata's health configuration](#reload-health-configuration) to make your changes live. + +### Silence an individual alarm + +Instead of disabling an alarm altogether, or even disabling _all_ alarms, you can silence individual alarms by changing +one line in a given health entity. To silence any single alarm, change the `to:` line in its entity to `silent`. + +```yaml + to: silent +``` + +## Write a new health entity + +While tuning existing alarms may work in some cases, you may need to write entirely new health entities based on how +your systems, containers, and applications work. + +Read Netdata's [health reference](/health/REFERENCE.md#health-entity-reference) for a full listing of the format, +syntax, and functionality of health entities. + +To write a new health entity into a new file, navigate to your [Netdata config directory](/docs/configure/nodes.md), +then use `touch` to create a new file in the `health.d/` directory. Use `edit-config` to start editing the file. + +As an example, let's create a `ram-usage.conf` file. + +```bash +sudo touch health.d/ram-usage.conf +sudo ./edit-config health.d/ram-usage.conf +``` + +For example, here is a health entity that triggers a warning alarm when a node's RAM usage rises above 80%, and a +critical alarm above 90%: + +```yaml + alarm: ram_usage + on: system.ram +lookup: average -1m percentage of used + units: % + every: 1m + warn: $this > 80 + crit: $this > 90 + info: The percentage of RAM being used by the system. +``` + +Let's look into each of the lines to see how they create a working health entity. + +- `alarm`: The name for your new entity. The name needs to follow these requirements: + - Any alphabet letter or number. + - The symbols `.` and `_`. + - Cannot be `chart name`, `dimension name`, `family name`, or `chart variable names`. +- `on`: Which chart the entity listens to. +- `lookup`: Which metrics the alarm monitors, the duration of time to monitor, and how to process the metrics into a + usable format. + - `average`: Calculate the average of all the metrics collected. + - `-1m`: Use metrics from 1 minute ago until now to calculate that average. + - `percentage`: Clarify that we're calculating a percentage of RAM usage. + - `of used`: Specify which dimension (`used`) on the `system.ram` chart you want to monitor with this entity. +- `units`: Use percentages rather than absolute units. +- `every`: How often to perform the `lookup` calculation to decide whether or not to trigger this alarm. +- `warn`/`crit`: The value at which Netdata should trigger a warning or critical alarm. This example uses simple + syntax, but most pre-configured health entities use + [hysteresis](/health/REFERENCE.md#special-usage-of-the-conditional-operator) to avoid superfluous notifications. +- `info`: A description of the alarm, which will appear in the dashboard and notifications. + +In human-readable format: + +> This health entity, named **ram_usage**, watches the **system.ram** chart. It looks up the last **1 minute** of +> metrics from the **used** dimension and calculates the **average** of all those metrics in a **percentage** format, +> using a **% unit**. The entity performs this lookup **every minute**. +> +> If the average RAM usage percentage over the last 1 minute is **more than 80%**, the entity triggers a warning alarm. +> If the usage is **more than 90%**, the entity triggers a critical alarm. + +When you finish writing this new health entity, [reload Netdata's health configuration](#reload-health-configuration) to +see it live on the local dashboard or Netdata Cloud. + +## Reload health configuration + +To make any changes to your health configuration live, you must reload Netdata's health monitoring system. To do that +without restarting all of Netdata, run `netdatacli reload-health` or `killall -USR2 netdata`. + +## What's next? + +With your health entities configured properly, it's time to [enable +notifications](/docs/monitor/enable-notifications.md) to get notified whenever a node reaches a warning or critical +state. + +To build complex, dynamic alarms, read our guide on [dimension templates](/docs/guides/monitor/dimension-templates.md). + +[](<>) |