mirror of https://github.com/Icinga/icinga2.git
1133 lines
45 KiB
Markdown
1133 lines
45 KiB
Markdown
# Advanced Topics <a id="advanced-topics"></a>
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This chapter covers a number of advanced topics. If you're new to Icinga, you
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can safely skip over things you're not interested in.
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## Downtimes <a id="downtimes"></a>
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Downtimes can be scheduled for planned server maintenance or
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any other targeted service outage you are aware of in advance.
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Downtimes will suppress any notifications, and may trigger other
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downtimes too. If the downtime was set by accident, or the duration
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exceeds the maintenance, you can manually cancel the downtime.
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Planned downtimes will also be taken into account for SLA reporting
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tools calculating the SLAs based on the state and downtime history.
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Multiple downtimes for a single object may overlap. This is useful
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when you want to extend your maintenance window taking longer than expected.
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If there are multiple downtimes triggered for one object, the overall downtime depth
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will be greater than `1`.
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If the downtime was scheduled after the problem changed to a critical hard
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state triggering a problem notification, and the service recovers during
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the downtime window, the recovery notification won't be suppressed.
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### Fixed and Flexible Downtimes <a id="fixed-flexible-downtimes"></a>
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A `fixed` downtime will be activated at the defined start time, and
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removed at the end time. During this time window the service state
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will change to `NOT-OK` and then actually trigger the downtime.
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Notifications are suppressed and the downtime depth is incremented.
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Common scenarios are a planned distribution upgrade on your linux
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servers, or database updates in your warehouse. The customer knows
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about a fixed downtime window between 23:00 and 24:00. After 24:00
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all problems should be alerted again. Solution is simple -
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schedule a `fixed` downtime starting at 23:00 and ending at 24:00.
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Unlike a `fixed` downtime, a `flexible` downtime will be triggered
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by the state change in the time span defined by start and end time,
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and then last for the specified duration in minutes.
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Imagine the following scenario: Your service is frequently polled
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by users trying to grab free deleted domains for immediate registration.
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Between 07:30 and 08:00 the impact will hit for 15 minutes and generate
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a network outage visible to the monitoring. The service is still alive,
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but answering too slow to Icinga 2 service checks.
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For that reason, you may want to schedule a downtime between 07:30 and
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08:00 with a duration of 15 minutes. The downtime will then last from
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its trigger time until the duration is over. After that, the downtime
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is removed (may happen before or after the actual end time!).
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### Scheduling a downtime <a id="scheduling-downtime"></a>
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You can schedule a downtime either by using the Icinga 2 API action
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[schedule-downtime](12-icinga2-api.md#icinga2-api-actions-schedule-downtime) or
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by sending an [external command](14-features.md#external-commands).
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#### Fixed Downtime <a id="fixed-downtime"></a>
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If the host/service changes into a NOT-OK state between the start and
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end time window, the downtime will be marked as `in effect` and
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increases the downtime depth counter.
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```
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| | |
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start | end
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trigger time
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```
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#### Flexible Downtime <a id="flexible-downtime"></a>
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A flexible downtime defines a time window where the downtime may be
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triggered from a host/service NOT-OK state change. It will then last
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until the specified time duration is reached. That way it can happen
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that the downtime end time is already gone, but the downtime ends
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at `trigger time + duration`.
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```
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| | |
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start | end actual end time
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|--------------duration--------|
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trigger time
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```
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### Triggered Downtimes <a id="triggered-downtimes"></a>
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This is optional when scheduling a downtime. If there is already a downtime
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scheduled for a future maintenance, the current downtime can be triggered by
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that downtime. This renders useful if you have scheduled a host downtime and
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are now scheduling a child host's downtime getting triggered by the parent
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downtime on `NOT-OK` state change.
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### Recurring Downtimes <a id="recurring-downtimes"></a>
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[ScheduledDowntime objects](09-object-types.md#objecttype-scheduleddowntime) can be used to set up
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recurring downtimes for services.
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Example:
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apply ScheduledDowntime "backup-downtime" to Service {
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author = "icingaadmin"
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comment = "Scheduled downtime for backup"
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ranges = {
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monday = "02:00-03:00"
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tuesday = "02:00-03:00"
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wednesday = "02:00-03:00"
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thursday = "02:00-03:00"
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friday = "02:00-03:00"
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saturday = "02:00-03:00"
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sunday = "02:00-03:00"
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}
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assign where "backup" in service.groups
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}
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## Comments <a id="comments-intro"></a>
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Comments can be added at runtime and are persistent over restarts. You can
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add useful information for others on repeating incidents (for example
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"last time syslog at 100% cpu on 17.10.2013 due to stale nfs mount") which
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is primarily accessible using web interfaces.
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You can add a comment either by using the Icinga 2 API action
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[add-comment](12-icinga2-api.md#icinga2-api-actions-add-comment) or
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by sending an [external command](14-features.md#external-commands).
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## Acknowledgements <a id="acknowledgements"></a>
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If a problem persists and notifications have been sent, you can
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acknowledge the problem. That way other users will get
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a notification that you're aware of the issue and probably are
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already working on a fix.
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Note: Acknowledgements also add a new [comment](08-advanced-topics.md#comments-intro)
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which contains the author and text fields.
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You can send an acknowledgement either by using the Icinga 2 API action
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[acknowledge-problem](12-icinga2-api.md#icinga2-api-actions-acknowledge-problem) or
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by sending an [external command](14-features.md#external-commands).
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### Sticky Acknowledgements <a id="sticky-acknowledgements"></a>
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The acknowledgement is removed if a state change occurs or if the host/service
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recovers (OK/Up state).
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If you acknowledge a problem once you've received a `Critical` notification,
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the acknowledgement will be removed if there is a state transition to `Warning`.
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```
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OK -> WARNING -> CRITICAL -> WARNING -> OK
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```
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If you prefer to keep the acknowledgement until the problem is resolved (`OK`
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recovery) you need to enable the `sticky` parameter.
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### Expiring Acknowledgements <a id="expiring-acknowledgements"></a>
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Once a problem is acknowledged it may disappear from your `handled problems`
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dashboard and no-one ever looks at it again since it will suppress
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notifications too.
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This `fire-and-forget` action is quite common. If you're sure that a
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current problem should be resolved in the future at a defined time,
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you can define an expiration time when acknowledging the problem.
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Icinga 2 will clear the acknowledgement when expired and start to
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re-notify, if the problem persists.
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## Time Periods <a id="timeperiods"></a>
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[Time Periods](09-object-types.md#objecttype-timeperiod) define
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time ranges in Icinga where event actions are triggered, for
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example whether a service check is executed or not within
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the `check_period` attribute. Or a notification should be sent to
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users or not, filtered by the `period` and `notification_period`
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configuration attributes for `Notification` and `User` objects.
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> **Note**
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>
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> If you are familiar with Icinga 1.x, these time period definitions
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> are called `legacy timeperiods` in Icinga 2.
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>
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> An Icinga 2 legacy timeperiod requires the `ITL` provided template
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>`legacy-timeperiod`.
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The `TimePeriod` attribute `ranges` may contain multiple directives,
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including weekdays, days of the month, and calendar dates.
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These types may overlap/override other types in your ranges dictionary.
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The descending order of precedence is as follows:
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* Calendar date (2008-01-01)
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* Specific month date (January 1st)
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* Generic month date (Day 15)
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* Offset weekday of specific month (2nd Tuesday in December)
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* Offset weekday (3rd Monday)
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* Normal weekday (Tuesday)
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If you don't set any `check_period` or `notification_period` attribute
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on your configuration objects, Icinga 2 assumes `24x7` as time period
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as shown below.
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object TimePeriod "24x7" {
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import "legacy-timeperiod"
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display_name = "Icinga 2 24x7 TimePeriod"
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ranges = {
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"monday" = "00:00-24:00"
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"tuesday" = "00:00-24:00"
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"wednesday" = "00:00-24:00"
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"thursday" = "00:00-24:00"
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"friday" = "00:00-24:00"
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"saturday" = "00:00-24:00"
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"sunday" = "00:00-24:00"
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}
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}
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If your operation staff should only be notified during workhours,
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create a new timeperiod named `workhours` defining a work day from
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09:00 to 17:00.
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object TimePeriod "workhours" {
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import "legacy-timeperiod"
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display_name = "Icinga 2 8x5 TimePeriod"
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ranges = {
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"monday" = "09:00-17:00"
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"tuesday" = "09:00-17:00"
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"wednesday" = "09:00-17:00"
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"thursday" = "09:00-17:00"
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"friday" = "09:00-17:00"
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}
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}
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Furthermore if you wish to specify a notification period across midnight,
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you can define it the following way:
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object Timeperiod "across-midnight" {
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import "legacy-timeperiod"
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display_name = "Nightly Notification"
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ranges = {
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"saturday" = "22:00-24:00"
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"sunday" = "00:00-03:00"
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}
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}
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Below you can see another example for configuring timeperiods across several
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days, weeks or months. This can be useful when taking components offline
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for a distinct period of time.
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object Timeperiod "standby" {
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import "legacy-timeperiod"
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display_name = "Standby"
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ranges = {
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"2016-09-30 - 2016-10-30" = "00:00-24:00"
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}
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}
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Please note that the spaces before and after the dash are mandatory.
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Once your time period is configured you can Use the `period` attribute
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to assign time periods to `Notification` and `Dependency` objects:
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object Notification "mail" {
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import "generic-notification"
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host_name = "localhost"
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command = "mail-notification"
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users = [ "icingaadmin" ]
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period = "workhours"
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}
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### Time Periods Inclusion and Exclusion <a id="timeperiods-includes-excludes"></a>
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Sometimes it is necessary to exclude certain time ranges from
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your default time period definitions, for example, if you don't
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want to send out any notification during the holiday season,
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or if you only want to allow small time windows for executed checks.
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The [TimePeriod object](09-object-types.md#objecttype-timeperiod)
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provides the `includes` and `excludes` attributes to solve this issue.
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`prefer_includes` defines whether included or excluded time periods are
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preferred.
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The following example defines a time period called `holidays` where
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notifications should be suppressed:
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object TimePeriod "holidays" {
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import "legacy-timeperiod"
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ranges = {
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"january 1" = "00:00-24:00" //new year's day
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"july 4" = "00:00-24:00" //independence day
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"december 25" = "00:00-24:00" //christmas
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"december 31" = "18:00-24:00" //new year's eve (6pm+)
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"2017-04-16" = "00:00-24:00" //easter 2017
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"monday -1 may" = "00:00-24:00" //memorial day (last monday in may)
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"monday 1 september" = "00:00-24:00" //labor day (1st monday in september)
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"thursday 4 november" = "00:00-24:00" //thanksgiving (4th thursday in november)
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}
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}
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In addition to that the time period `weekends` defines an additional
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time window which should be excluded from notifications:
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object TimePeriod "weekends-excluded" {
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import "legacy-timeperiod"
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ranges = {
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"saturday" = "00:00-09:00,18:00-24:00"
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"sunday" = "00:00-09:00,18:00-24:00"
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}
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}
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The time period `prod-notification` defines the default time ranges
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and adds the excluded time period names as an array.
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object TimePeriod "prod-notification" {
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import "legacy-timeperiod"
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excludes = [ "holidays", "weekends-excluded" ]
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ranges = {
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"monday" = "00:00-24:00"
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"tuesday" = "00:00-24:00"
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"wednesday" = "00:00-24:00"
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"thursday" = "00:00-24:00"
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"friday" = "00:00-24:00"
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"saturday" = "00:00-24:00"
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"sunday" = "00:00-24:00"
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}
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}
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## External Check Results <a id="external-check-results"></a>
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Hosts or services which do not actively execute a check plugin to receive
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the state and output are called "passive checks" or "external check results".
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In this scenario an external client or script is sending in check results.
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You can feed check results into Icinga 2 with the following transport methods:
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* [process-check-result action](12-icinga2-api.md#icinga2-api-actions-process-check-result) available with the [REST API](12-icinga2-api.md#icinga2-api) (remote and local)
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* External command sent via command pipe (local only)
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Each time a new check result is received, the next expected check time
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is updated. This means that if there are no check result received from
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the external source, Icinga 2 will execute [freshness checks](08-advanced-topics.md#check-result-freshness).
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> **Note**
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>
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> The REST API action allows to specify the `check_source` attribute
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> which helps identifying the external sender. This is also visible
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> in Icinga Web 2 and the REST API queries.
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## Check Result Freshness <a id="check-result-freshness"></a>
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In Icinga 2 active check freshness is enabled by default. It is determined by the
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`check_interval` attribute and no incoming check results in that period of time.
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The threshold is calculated based on the last check execution time for actively executed checks:
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(last check execution time + check interval) > current time
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If this host/service receives check results from an [external source](08-advanced-topics.md#external-check-results),
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the threshold is based on the last time a check result was received:
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(last check result time + check interval) > current time
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> **Tip**
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>
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> The [process-check-result](12-icinga2-api.md#icinga2-api-actions-process-check-result) REST API
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> action allows to overrule the pre-defined check interval with a specified TTL in Icinga 2 v2.9+.
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If the freshness checks fail, Icinga 2 will execute the defined check command.
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Best practice is to define a [dummy](10-icinga-template-library.md#itl-dummy) `check_command` which gets
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executed when freshness checks fail.
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```
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apply Service "external-check" {
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check_command = "dummy"
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check_interval = 1m
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/* Set the state to UNKNOWN (3) if freshness checks fail. */
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vars.dummy_state = 3
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/* Use a runtime function to retrieve the last check time and more details. */
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vars.dummy_text = {{
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var service = get_service(macro("$host.name$"), macro("$service.name$"))
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var lastCheck = DateTime(service.last_check).to_string()
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return "No check results received. Last result time: " + lastCheck
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}}
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assign where "external" in host.vars.services
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}
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```
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References: [get_service](18-library-reference.md#objref-get_service), [macro](18-library-reference.md#scoped-functions-macro), [DateTime](18-library-reference.md#datetime-type).
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Example output in Icinga Web 2:
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## Check Flapping <a id="check-flapping"></a>
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Icinga 2 supports optional detection of hosts and services that are "flapping".
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Flapping occurs when a service or host changes state too frequently, which would result in a storm of problem and
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recovery notifications. With flapping detection enabled a flapping notification will be sent while other notifications are
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suppresed until it calms down after receiving the same status from checks a few times. Flapping detection can help detect
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configuration problems (wrong thresholds), troublesome services, or network problems.
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Flapping detection can be enabled or disabled using the `enable_flapping` attribute.
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The `flapping_threshold_high` and `flapping_threshold_low` attributes allows to specify the thresholds that control
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when a [host](09-object-types.md#objecttype-host) or [service](objecttype-service) is considered to be flapping.
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The default thresholds are 30% for high and 25% for low. If the computed flapping value exceeds the high threshold a
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host or service is considered flapping until it drops below the low flapping threshold.
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`FlappingStart` and `FlappingEnd` notifications will be sent out accordingly, if configured. See the chapter on
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[notifications](alert-notifications) for details
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> Note: There is no distinctions between hard and soft states with flapping. All state changes count and notifications
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> will be sent out regardless of the objects state.
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### How it works <a id="check-flapping-how-it-works"></a>
|
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Icinga 2 saves the last 20 state changes for every host and service. See the graphic below:
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All the states ware weighted, with the most recent one being worth the most (1.15) and the 20th the least (0.8). The
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states in between are fairly distributed. The final flapping value are the weighted state changes divided by the total
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count of 20.
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In the example above, the added states would have a total value of 7.82 (`0.84 + 0.86 + 0.88 + 0.9 + 0.98 + 1.06 + 1.12 + 1.18`).
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This yields a flapping percentage of 39.1% (`7.82 / 20 * 100`). As the default upper flapping threshold is 30%, it would be
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considered flapping.
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If the next seven check results then would not be state changes, the flapping percentage would fall below the lower threshold
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of 25% and therefore the host or service would recover from flapping.
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## Volatile Services <a id="volatile-services"></a>
|
||
|
||
By default all services remain in a non-volatile state. When a problem
|
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occurs, the `SOFT` state applies and once `max_check_attempts` attribute
|
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is reached with the check counter, a `HARD` state transition happens.
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Notifications are only triggered by `HARD` state changes and are then
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re-sent defined by the `interval` attribute.
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It may be reasonable to have a volatile service which stays in a `HARD`
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state type if the service stays in a `NOT-OK` state. That way each
|
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service recheck will automatically trigger a notification unless the
|
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service is acknowledged or in a scheduled downtime.
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||
|
||
## Monitoring Icinga 2 <a id="monitoring-icinga"></a>
|
||
|
||
Why should you do that? Icinga and its components run like any other
|
||
service application on your server. There are predictable issues
|
||
such as "disk space is running low" and your monitoring suffers from just
|
||
that.
|
||
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||
You would also like to ensure that features and backends are running
|
||
and storing required data. Be it the database backend where Icinga Web 2
|
||
presents fancy dashboards, forwarded metrics to Graphite or InfluxDB or
|
||
the entire distributed setup.
|
||
|
||
This list isn't complete but should help with your own setup.
|
||
Windows client specific checks are highlighted.
|
||
|
||
Type | Description | Plugins and CheckCommands
|
||
----------------|-------------------------------|-----------------------------------------------------
|
||
System | Filesystem | [disk](10-icinga-template-library.md#plugin-check-command-disk), [disk-windows](10-icinga-template-library.md#windows-plugins) (Windows Client)
|
||
System | Memory, Swap | [mem](10-icinga-template-library.md#plugin-contrib-command-mem), [swap](10-icinga-template-library.md#plugin-check-command-swap), [memory](10-icinga-template-library.md#windows-plugins) (Windows Client)
|
||
System | Hardware | [hpasm](10-icinga-template-library.md#plugin-contrib-command-hpasm), [ipmi-sensor](10-icinga-template-library.md#plugin-contrib-command-ipmi-sensor)
|
||
System | Virtualization | [VMware](10-icinga-template-library.md#plugin-contrib-vmware), [esxi_hardware](10-icinga-template-library.md#plugin-contrib-command-esxi-hardware)
|
||
System | Processes | [procs](10-icinga-template-library.md#plugin-check-command-processes), [service-windows](10-icinga-template-library.md#windows-plugins) (Windows Client)
|
||
System | System Activity Reports | [check_sar_perf](https://github.com/dnsmichi/icinga-plugins/blob/master/scripts/check_sar_perf.py)
|
||
System | I/O | [iostat](10-icinga-template-library.md#plugin-contrib-command-iostat)
|
||
System | Network interfaces | [nwc_health](10-icinga-template-library.md#plugin-contrib-command-nwc_health), [interfaces](10-icinga-template-library.md#plugin-contrib-command-interfaces)
|
||
System | Users | [users](10-icinga-template-library.md#plugin-check-command-users), [users-windows](10-icinga-template-library.md#windows-plugins) (Windows Client)
|
||
System | Logs | Forward them to [Elastic Stack](14-features.md#elastic-stack-integration) or [Graylog](14-features.md#graylog-integration) and add your own alerts.
|
||
System | NTP | [ntp_time](10-icinga-template-library.md#plugin-check-command-ntp-time)
|
||
System | Updates | [apt](10-icinga-template-library.md#plugin-check-command-apt), [yum](10-icinga-template-library.md#plugin-contrib-command-yum)
|
||
Icinga | Status & Stats | [icinga](10-icinga-template-library.md#itl-icinga) (more below)
|
||
Icinga | Cluster & Clients | [health checks](06-distributed-monitoring.md#distributed-monitoring-health-checks)
|
||
Database | MySQL | [mysql_health](10-icinga-template-library.md#plugin-contrib-command-mysql_health)
|
||
Database | PostgreSQL | [postgres](10-icinga-template-library.md#plugin-contrib-command-postgres)
|
||
Database | Housekeeping | Check the database size and growth and analyse metrics to examine trends.
|
||
Database | DB IDO | [ido](10-icinga-template-library.md#itl-icinga-ido) (more below)
|
||
Webserver | Apache2, Nginx, etc. | [http](10-icinga-template-library.md#plugin-check-command-http), [apache_status](10-icinga-template-library.md#plugin-contrib-command-apache_status), [nginx_status](10-icinga-template-library.md#plugin-contrib-command-nginx_status)
|
||
Webserver | Certificates | [http](10-icinga-template-library.md#plugin-check-command-http)
|
||
Webserver | Authorization | [http](10-icinga-template-library.md#plugin-check-command-http)
|
||
Notifications | Mail (queue) | [smtp](10-icinga-template-library.md#plugin-check-command-smtp), [mailq](10-icinga-template-library.md#plugin-check-command-mailq)
|
||
Notifications | SMS (GSM modem) | [check_sms3_status](https://exchange.icinga.com/netways/check_sms3status)
|
||
Notifications | Messengers, Cloud services | XMPP, Twitter, IRC, Telegram, PagerDuty, VictorOps, etc.
|
||
Metrics | PNP, RRDTool | [check_pnp_rrds](https://github.com/lingej/pnp4nagios/tree/master/scripts) checks for stale RRD files.
|
||
Metrics | Graphite | [graphite](10-icinga-template-library.md#plugin-contrib-command-graphite)
|
||
Metrics | InfluxDB | [check_influxdb](https://exchange.icinga.com/Mikanoshi/InfluxDB+data+monitoring+plugin)
|
||
Metrics | Elastic Stack | [elasticsearch](10-icinga-template-library.md#plugin-contrib-command-elasticsearch), [Elastic Stack integration](14-features.md#elastic-stack-integration)
|
||
Metrics | Graylog | [Graylog integration](14-features.md#graylog-integration)
|
||
|
||
|
||
The [icinga](10-icinga-template-library.md#itl-icinga) CheckCommand provides metrics for the runtime stats of
|
||
Icinga 2. You can forward them to your preferred graphing solution.
|
||
If you require more metrics you can also query the [REST API](12-icinga2-api.md#icinga2-api) and write
|
||
your own custom check plugin. Or you keep using the built-in [object accessor functions](08-advanced-topics.md#access-object-attributes-at-runtime)
|
||
to calculate stats in-memory.
|
||
|
||
There is a built-in [ido](10-icinga-template-library.md#itl-icinga-ido) check available for DB IDO MySQL/PostgreSQL
|
||
which provides additional metrics for the IDO database.
|
||
|
||
```
|
||
apply Service "ido-mysql" {
|
||
check_command = "ido"
|
||
|
||
vars.ido_type = "IdoMysqlConnection"
|
||
vars.ido_name = "ido-mysql" //the name defined in /etc/icinga2/features-enabled/ido-mysql.conf
|
||
|
||
assign where match("master*.localdomain", host.name)
|
||
}
|
||
```
|
||
|
||
More specific database queries can be found in the [DB IDO](14-features.md#db-ido) chapter.
|
||
|
||
Distributed setups should include specific [health checks](06-distributed-monitoring.md#distributed-monitoring-health-checks).
|
||
You might also want to add additional checks for SSL certificate expiration.
|
||
|
||
|
||
## Advanced Configuration Hints <a id="advanced-configuration-hints"></a>
|
||
|
||
### Advanced Use of Apply Rules <a id="advanced-use-of-apply-rules"></a>
|
||
|
||
[Apply rules](03-monitoring-basics.md#using-apply) can be used to create a rule set which is
|
||
entirely based on host objects and their attributes.
|
||
In addition to that [apply for and custom attribute override](03-monitoring-basics.md#using-apply-for)
|
||
extend the possibilities.
|
||
|
||
The following example defines a dictionary on the host object which contains
|
||
configuration attributes for multiple web servers. This then used to add three checks:
|
||
|
||
* A `ping4` check using the local IP `address` of the web server.
|
||
* A `tcp` check querying the TCP port where the HTTP service is running on.
|
||
* If the `url` key is defined, the third apply for rule will create service objects using the `http` CheckCommand.
|
||
In addition to that you can optionally define the `ssl` attribute which enables HTTPS checks.
|
||
|
||
Host definition:
|
||
|
||
object Host "webserver01" {
|
||
import "generic-host"
|
||
address = "192.168.56.200"
|
||
vars.os = "Linux"
|
||
|
||
vars.webserver = {
|
||
instance["status"] = {
|
||
address = "192.168.56.201"
|
||
port = "80"
|
||
url = "/status"
|
||
}
|
||
instance["tomcat"] = {
|
||
address = "192.168.56.202"
|
||
port = "8080"
|
||
}
|
||
instance["icingaweb2"] = {
|
||
address = "192.168.56.210"
|
||
port = "443"
|
||
url = "/icingaweb2"
|
||
ssl = true
|
||
}
|
||
}
|
||
}
|
||
|
||
Service apply for definitions:
|
||
|
||
apply Service "webserver_ping" for (instance => config in host.vars.webserver.instance) {
|
||
display_name = "webserver_" + instance
|
||
check_command = "ping4"
|
||
|
||
vars.ping_address = config.address
|
||
|
||
assign where host.vars.webserver.instance
|
||
}
|
||
|
||
apply Service "webserver_port" for (instance => config in host.vars.webserver.instance) {
|
||
display_name = "webserver_" + instance + "_" + config.port
|
||
check_command = "tcp"
|
||
|
||
vars.tcp_address = config.address
|
||
vars.tcp_port = config.port
|
||
|
||
assign where host.vars.webserver.instance
|
||
}
|
||
|
||
apply Service "webserver_url" for (instance => config in host.vars.webserver.instance) {
|
||
display_name = "webserver_" + instance + "_" + config.url
|
||
check_command = "http"
|
||
|
||
vars.http_address = config.address
|
||
vars.http_port = config.port
|
||
vars.http_uri = config.url
|
||
|
||
if (config.ssl) {
|
||
vars.http_ssl = config.ssl
|
||
}
|
||
|
||
assign where config.url != ""
|
||
}
|
||
|
||
The variables defined in the host dictionary are not using the typical custom attribute
|
||
prefix recommended for CheckCommand parameters. Instead they are re-used for multiple
|
||
service checks in this example.
|
||
In addition to defining check parameters this way, you can also enrich the `display_name`
|
||
attribute with more details. This will be shown in in Icinga Web 2 for example.
|
||
|
||
### Use Functions in Object Configuration <a id="use-functions-object-config"></a>
|
||
|
||
There is a limited scope where functions can be used as object attributes such as:
|
||
|
||
* As value for [Custom Attributes](03-monitoring-basics.md#custom-attributes-functions)
|
||
* Returning boolean expressions for [set_if](08-advanced-topics.md#use-functions-command-arguments-setif) inside command arguments
|
||
* Returning a [command](08-advanced-topics.md#use-functions-command-attribute) array inside command objects
|
||
|
||
The other way around you can create objects dynamically using your own global functions.
|
||
|
||
> **Note**
|
||
>
|
||
> Functions called inside command objects share the same global scope as runtime macros.
|
||
> Therefore you can access host custom attributes like `host.vars.os`, or any other
|
||
> object attribute from inside the function definition used for [set_if](08-advanced-topics.md#use-functions-command-arguments-setif) or [command](08-advanced-topics.md#use-functions-command-attribute).
|
||
|
||
Tips when implementing functions:
|
||
|
||
* Use [log()](18-library-reference.md#global-functions-log) to dump variables. You can see the output
|
||
inside the `icinga2.log` file depending in your log severity
|
||
* Use the `icinga2 console` to test basic functionality (e.g. iterating over a dictionary)
|
||
* Build them step-by-step. You can always refactor your code later on.
|
||
|
||
#### Register and Use Global Functions <a id="use-functions-global-register"></a>
|
||
|
||
[Functions](17-language-reference.md#functions) can be registered into the global scope. This allows custom functions being available
|
||
in objects and other functions. Keep in mind that these functions are not marked
|
||
as side-effect-free and as such are not available via the REST API.
|
||
|
||
Add a new configuration file `functions.conf` and include it into the [icinga2.conf](04-configuring-icinga-2.md#icinga2-conf)
|
||
configuration file in the very beginning, e.g. after `constants.conf`. You can also manage global
|
||
functions inside `constants.conf` if you prefer.
|
||
|
||
The following function converts a given state parameter into a returned string value. The important
|
||
bits for registering it into the global scope are:
|
||
|
||
* `globals.<unique_function_name>` adds a new globals entry.
|
||
* `function()` specifies that a call to `state_to_string()` executes a function.
|
||
* Function parameters are defined inside the `function()` definition.
|
||
|
||
```
|
||
globals.state_to_string = function(state) {
|
||
if (state == 2) {
|
||
return "Critical"
|
||
} else if (state == 1) {
|
||
return "Warning"
|
||
} else if (state == 0) {
|
||
return "OK"
|
||
} else if (state == 3) {
|
||
return "Unknown"
|
||
} else {
|
||
log(LogWarning, "state_to_string", "Unknown state " + state + " provided.")
|
||
}
|
||
}
|
||
```
|
||
|
||
The else-condition allows for better error handling. This warning will be shown in the Icinga 2
|
||
log file once the function is called.
|
||
|
||
> **Note**
|
||
>
|
||
> If these functions are used in a distributed environment, you must ensure to deploy them
|
||
> everywhere needed.
|
||
|
||
In order to test-drive the newly created function, restart Icinga 2 and use the [debug console](11-cli-commands.md#cli-command-console)
|
||
to connect to the REST API.
|
||
|
||
```
|
||
$ ICINGA2_API_PASSWORD=icinga icinga2 console --connect 'https://root@localhost:5665/'
|
||
Icinga 2 (version: v2.8.1-373-g4bea6d25c)
|
||
<1> => globals.state_to_string(1)
|
||
"Warning"
|
||
<2> => state_to_string(2)
|
||
"Critical"
|
||
```
|
||
|
||
You can see that this function is now registered into the [global scope](17-language-reference.md#variable-scopes). The function call
|
||
`state_to_string()` can be used in any object at static config compile time or inside runtime
|
||
lambda functions.
|
||
|
||
The following service object example uses the service state and converts it to string output.
|
||
The function definition is not optimized and is enrolled for better readability including a log message.
|
||
|
||
```
|
||
object Service "state-test" {
|
||
check_command = "dummy"
|
||
host_name = NodeName
|
||
|
||
vars.dummy_state = 2
|
||
|
||
vars.dummy_text = {{
|
||
var h = macro("$host.name$")
|
||
var s = macro("$service.name$")
|
||
|
||
var state = get_service(h, s).state
|
||
|
||
log(LogInformation, "dummy_state", "Host: " + h + " Service: " + s + " State: " + state)
|
||
|
||
return state_to_string(state)
|
||
}}
|
||
}
|
||
```
|
||
|
||
|
||
#### Use Custom Functions as Attribute <a id="custom-functions-as-attribute"></a>
|
||
|
||
To use custom functions as attributes, the function must be defined in a
|
||
slightly unexpected way. The following example shows how to assign values
|
||
depending on group membership. All hosts in the `slow-lan` host group use 300
|
||
as value for `ping_wrta`, all other hosts use 100.
|
||
|
||
globals.group_specific_value = function(group, group_value, non_group_value) {
|
||
return function() use (group, group_value, non_group_value) {
|
||
if (group in host.groups) {
|
||
return group_value
|
||
} else {
|
||
return non_group_value
|
||
}
|
||
}
|
||
}
|
||
|
||
apply Service "ping4" {
|
||
import "generic-service"
|
||
check_command = "ping4"
|
||
|
||
vars.ping_wrta = group_specific_value("slow-lan", 300, 100)
|
||
vars.ping_crta = group_specific_value("slow-lan", 500, 200)
|
||
|
||
assign where true
|
||
}
|
||
|
||
#### Use Functions in Assign Where Expressions <a id="use-functions-assign-where"></a>
|
||
|
||
If a simple expression for matching a name or checking if an item
|
||
exists in an array or dictionary does not fit, you should consider
|
||
writing your own global [functions](17-language-reference.md#functions).
|
||
You can call them inside `assign where` and `ignore where` expressions
|
||
for [apply rules](03-monitoring-basics.md#using-apply-expressions) or
|
||
[group assignments](03-monitoring-basics.md#group-assign-intro) just like
|
||
any other global functions for example [match](18-library-reference.md#global-functions-match).
|
||
|
||
The following example requires the host `myprinter` being added
|
||
to the host group `printers-lexmark` but only if the host uses
|
||
a template matching the name `lexmark*`.
|
||
|
||
template Host "lexmark-printer-host" {
|
||
vars.printer_type = "Lexmark"
|
||
}
|
||
|
||
object Host "myprinter" {
|
||
import "generic-host"
|
||
import "lexmark-printer-host"
|
||
|
||
address = "192.168.1.1"
|
||
}
|
||
|
||
/* register a global function for the assign where call */
|
||
globals.check_host_templates = function(host, search) {
|
||
/* iterate over all host templates and check if the search matches */
|
||
for (tmpl in host.templates) {
|
||
if (match(search, tmpl)) {
|
||
return true
|
||
}
|
||
}
|
||
|
||
/* nothing matched */
|
||
return false
|
||
}
|
||
|
||
object HostGroup "printers-lexmark" {
|
||
display_name = "Lexmark Printers"
|
||
/* call the global function and pass the arguments */
|
||
assign where check_host_templates(host, "lexmark*")
|
||
}
|
||
|
||
|
||
Take a different more complex example: All hosts with the
|
||
custom attribute `vars_app` as nested dictionary should be
|
||
added to the host group `ABAP-app-server`. But only if the
|
||
`app_type` for all entries is set to `ABAP`.
|
||
|
||
It could read as wildcard match for nested dictionaries:
|
||
|
||
where host.vars.vars_app["*"].app_type == "ABAP"
|
||
|
||
The solution for this problem is to register a global
|
||
function which checks the `app_type` for all hosts
|
||
with the `vars_app` dictionary.
|
||
|
||
object Host "appserver01" {
|
||
check_command = "dummy"
|
||
vars.vars_app["ABC"] = { app_type = "ABAP" }
|
||
}
|
||
object Host "appserver02" {
|
||
check_command = "dummy"
|
||
vars.vars_app["DEF"] = { app_type = "ABAP" }
|
||
}
|
||
|
||
globals.check_app_type = function(host, type) {
|
||
/* ensure that other hosts without the custom attribute do not match */
|
||
if (typeof(host.vars.vars_app) != Dictionary) {
|
||
return false
|
||
}
|
||
|
||
/* iterate over the vars_app dictionary */
|
||
for (key => val in host.vars.vars_app) {
|
||
/* if the value is a dictionary and if contains the app_type being the requested type */
|
||
if (typeof(val) == Dictionary && val.app_type == type) {
|
||
return true
|
||
}
|
||
}
|
||
|
||
/* nothing matched */
|
||
return false
|
||
}
|
||
|
||
object HostGroup "ABAP-app-server" {
|
||
assign where check_app_type(host, "ABAP")
|
||
}
|
||
|
||
|
||
#### Use Functions in Command Arguments set_if <a id="use-functions-command-arguments-setif"></a>
|
||
|
||
The `set_if` attribute inside the command arguments definition in the
|
||
[CheckCommand object definition](09-object-types.md#objecttype-checkcommand) is primarily used to
|
||
evaluate whether the command parameter should be set or not.
|
||
|
||
By default you can evaluate runtime macros for their existence. If the result is not an empty
|
||
string, the command parameter is passed. This becomes fairly complicated when want to evaluate
|
||
multiple conditions and attributes.
|
||
|
||
The following example was found on the community support channels. The user had defined a host
|
||
dictionary named `compellent` with the key `disks`. This was then used inside service apply for rules.
|
||
|
||
object Host "dict-host" {
|
||
check_command = "check_compellent"
|
||
vars.compellent["disks"] = {
|
||
file = "/var/lib/check_compellent/san_disks.0.json",
|
||
checks = ["disks"]
|
||
}
|
||
}
|
||
|
||
The more significant problem was to only add the command parameter `--disk` to the plugin call
|
||
when the dictionary `compellent` contains the key `disks`, and omit it if not found.
|
||
|
||
By defining `set_if` as [abbreviated lambda function](17-language-reference.md#nullary-lambdas)
|
||
and evaluating the host custom attribute `compellent` containing the `disks` this problem was
|
||
solved like this:
|
||
|
||
object CheckCommand "check_compellent" {
|
||
command = [ "/usr/bin/check_compellent" ]
|
||
arguments = {
|
||
"--disks" = {
|
||
set_if = {{
|
||
var host_vars = host.vars
|
||
log(host_vars)
|
||
var compel = host_vars.compellent
|
||
log(compel)
|
||
compel.contains("disks")
|
||
}}
|
||
}
|
||
}
|
||
}
|
||
|
||
This implementation uses the dictionary type method [contains](18-library-reference.md#dictionary-contains)
|
||
and will fail if `host.vars.compellent` is not of the type `Dictionary`.
|
||
Therefore you can extend the checks using the [typeof](17-language-reference.md#types) function.
|
||
|
||
You can test the types using the `icinga2 console`:
|
||
|
||
# icinga2 console
|
||
Icinga (version: v2.3.0-193-g3eb55ad)
|
||
<1> => srv_vars.compellent["check_a"] = { file="outfile_a.json", checks = [ "disks", "fans" ] }
|
||
null
|
||
<2> => srv_vars.compellent["check_b"] = { file="outfile_b.json", checks = [ "power", "voltages" ] }
|
||
null
|
||
<3> => typeof(srv_vars.compellent)
|
||
type 'Dictionary'
|
||
<4> =>
|
||
|
||
The more programmatic approach for `set_if` could look like this:
|
||
|
||
"--disks" = {
|
||
set_if = {{
|
||
var srv_vars = service.vars
|
||
if(len(srv_vars) > 0) {
|
||
if (typeof(srv_vars.compellent) == Dictionary) {
|
||
return srv_vars.compellent.contains("disks")
|
||
} else {
|
||
log(LogInformationen, "checkcommand set_if", "custom attribute compellent_checks is not a dictionary, ignoring it.")
|
||
return false
|
||
}
|
||
} else {
|
||
log(LogWarning, "checkcommand set_if", "empty custom attributes")
|
||
return false
|
||
}
|
||
}}
|
||
}
|
||
|
||
|
||
#### Use Functions as Command Attribute <a id="use-functions-command-attribute"></a>
|
||
|
||
This comes in handy for [NotificationCommands](09-object-types.md#objecttype-notificationcommand)
|
||
or [EventCommands](09-object-types.md#objecttype-eventcommand) which does not require
|
||
a returned checkresult including state/output.
|
||
|
||
The following example was taken from the community support channels. The requirement was to
|
||
specify a custom attribute inside the notification apply rule and decide which notification
|
||
script to call based on that.
|
||
|
||
object User "short-dummy" {
|
||
}
|
||
|
||
object UserGroup "short-dummy-group" {
|
||
assign where user.name == "short-dummy"
|
||
}
|
||
|
||
apply Notification "mail-admins-short" to Host {
|
||
import "mail-host-notification"
|
||
command = "mail-host-notification-test"
|
||
user_groups = [ "short-dummy-group" ]
|
||
vars.short = true
|
||
assign where host.vars.notification.mail
|
||
}
|
||
|
||
The solution is fairly simple: The `command` attribute is implemented as function returning
|
||
an array required by the caller Icinga 2.
|
||
The local variable `mailscript` sets the default value for the notification scrip location.
|
||
If the notification custom attribute `short` is set, it will override the local variable `mailscript`
|
||
with a new value.
|
||
The `mailscript` variable is then used to compute the final notification command array being
|
||
returned.
|
||
|
||
You can omit the `log()` calls, they only help debugging.
|
||
|
||
object NotificationCommand "mail-host-notification-test" {
|
||
command = {{
|
||
log("command as function")
|
||
var mailscript = "mail-host-notification-long.sh"
|
||
if (notification.vars.short) {
|
||
mailscript = "mail-host-notification-short.sh"
|
||
}
|
||
log("Running command")
|
||
log(mailscript)
|
||
|
||
var cmd = [ SysconfDir + "/icinga2/scripts/" + mailscript ]
|
||
log(LogCritical, "me", cmd)
|
||
return cmd
|
||
}}
|
||
|
||
env = {
|
||
}
|
||
}
|
||
|
||
|
||
### Access Object Attributes at Runtime <a id="access-object-attributes-at-runtime"></a>
|
||
|
||
The [Object Accessor Functions](18-library-reference.md#object-accessor-functions)
|
||
can be used to retrieve references to other objects by name.
|
||
|
||
This allows you to access configuration and runtime object attributes. A detailed
|
||
list can be found [here](09-object-types.md#object-types).
|
||
|
||
#### Access Object Attributes at Runtime: Cluster Check <a id="access-object-attributes-at-runtime-cluster-check"></a>
|
||
|
||
This is a simple cluster example for accessing two host object states and calculating a virtual
|
||
cluster state and output:
|
||
|
||
```
|
||
object Host "cluster-host-01" {
|
||
check_command = "dummy"
|
||
vars.dummy_state = 2
|
||
vars.dummy_text = "This host is down."
|
||
}
|
||
|
||
object Host "cluster-host-02" {
|
||
check_command = "dummy"
|
||
vars.dummy_state = 0
|
||
vars.dummy_text = "This host is up."
|
||
}
|
||
|
||
object Host "cluster" {
|
||
check_command = "dummy"
|
||
vars.cluster_nodes = [ "cluster-host-01", "cluster-host-02" ]
|
||
|
||
vars.dummy_state = {{
|
||
var up_count = 0
|
||
var down_count = 0
|
||
var cluster_nodes = macro("$cluster_nodes$")
|
||
|
||
for (node in cluster_nodes) {
|
||
if (get_host(node).state > 0) {
|
||
down_count += 1
|
||
} else {
|
||
up_count += 1
|
||
}
|
||
}
|
||
|
||
if (up_count >= down_count) {
|
||
return 0 //same up as down -> UP
|
||
} else {
|
||
return 2 //something is broken
|
||
}
|
||
}}
|
||
|
||
vars.dummy_text = {{
|
||
var output = "Cluster hosts:\n"
|
||
var cluster_nodes = macro("$cluster_nodes$")
|
||
|
||
for (node in cluster_nodes) {
|
||
output += node + ": " + get_host(node).last_check_result.output + "\n"
|
||
}
|
||
|
||
return output
|
||
}}
|
||
}
|
||
```
|
||
|
||
#### Time Dependent Thresholds <a id="access-object-attributes-at-runtime-time-dependent-thresholds"></a>
|
||
|
||
The following example sets time dependent thresholds for the load check based on the current
|
||
time of the day compared to the defined time period.
|
||
|
||
```
|
||
object TimePeriod "backup" {
|
||
import "legacy-timeperiod"
|
||
|
||
ranges = {
|
||
monday = "02:00-03:00"
|
||
tuesday = "02:00-03:00"
|
||
wednesday = "02:00-03:00"
|
||
thursday = "02:00-03:00"
|
||
friday = "02:00-03:00"
|
||
saturday = "02:00-03:00"
|
||
sunday = "02:00-03:00"
|
||
}
|
||
}
|
||
|
||
object Host "webserver-with-backup" {
|
||
check_command = "hostalive"
|
||
address = "127.0.0.1"
|
||
}
|
||
|
||
object Service "webserver-backup-load" {
|
||
check_command = "load"
|
||
host_name = "webserver-with-backup"
|
||
|
||
vars.load_wload1 = {{
|
||
if (get_time_period("backup").is_inside) {
|
||
return 20
|
||
} else {
|
||
return 5
|
||
}
|
||
}}
|
||
vars.load_cload1 = {{
|
||
if (get_time_period("backup").is_inside) {
|
||
return 40
|
||
} else {
|
||
return 10
|
||
}
|
||
}}
|
||
}
|
||
```
|
||
|
||
|
||
## Advanced Value Types <a id="advanced-value-types"></a>
|
||
|
||
In addition to the default value types Icinga 2 also uses a few other types
|
||
to represent its internal state. The following types are exposed via the [API](12-icinga2-api.md#icinga2-api).
|
||
|
||
### CheckResult <a id="advanced-value-types-checkresult"></a>
|
||
|
||
Name | Type | Description
|
||
--------------------------|-----------------------|----------------------------------
|
||
exit\_status | Number | The exit status returned by the check execution.
|
||
output | String | The check output.
|
||
performance\_data | Array | Array of [performance data values](08-advanced-topics.md#advanced-value-types-perfdatavalue).
|
||
check\_source | String | Name of the node executing the check.
|
||
state | Number | The current state (0 = OK, 1 = WARNING, 2 = CRITICAL, 3 = UNKNOWN).
|
||
command | Value | Array of command with shell-escaped arguments or command line string.
|
||
execution\_start | Timestamp | Check execution start time (as a UNIX timestamp).
|
||
execution\_end | Timestamp | Check execution end time (as a UNIX timestamp).
|
||
schedule\_start | Timestamp | Scheduled check execution start time (as a UNIX timestamp).
|
||
schedule\_end | Timestamp | Scheduled check execution end time (as a UNIX timestamp).
|
||
active | Boolean | Whether the result is from an active or passive check.
|
||
vars\_before | Dictionary | Internal attribute used for calculations.
|
||
vars\_after | Dictionary | Internal attribute used for calculations.
|
||
ttl | Number | Time-to-live duration in seconds for this check result. The next expected check result is `now + ttl` where freshness checks are executed.
|
||
|
||
### PerfdataValue <a id="advanced-value-types-perfdatavalue"></a>
|
||
|
||
Icinga 2 parses performance data strings returned by check plugins and makes the information available to external interfaces (e.g. [GraphiteWriter](09-object-types.md#objecttype-graphitewriter) or the [Icinga 2 API](12-icinga2-api.md#icinga2-api)).
|
||
|
||
Name | Type | Description
|
||
--------------------------|-----------------------|----------------------------------
|
||
label | String | Performance data label.
|
||
value | Number | Normalized performance data value without unit.
|
||
counter | Boolean | Enabled if the original value contains `c` as unit. Defaults to `false`.
|
||
unit | String | Unit of measurement (`seconds`, `bytes`. `percent`) according to the [plugin API](05-service-monitoring.md#service-monitoring-plugin-api).
|
||
crit | Value | Critical threshold value.
|
||
warn | Value | Warning threshold value.
|
||
min | Value | Minimum value returned by the check.
|
||
max | Value | Maximum value returned by the check.
|