Alert types

Kibana supplies alerts types in two ways: some are built into Kibana, while domain-specific alert types are registered by Kibana apps such as APM, Metrics, and Uptime.

This section covers built-in alert types. For domain-specific alert types, refer to the documentation for that app.

Currently Kibana provides one built-in alert type: the Index threshold type.

The index threshold alert type is designed to run an Elasticsearch query over indices, aggregating field values from documents, comparing them to threshold values, and scheduling actions to run when the thresholds are met.

An index threshold alert can be created from the Create button in the alert management UI. Fill in the general alert details, then select Index Threshold.

The index threshold has 5 clauses that define the condition to detect.

If data is available and all clauses have been defined, a preview chart will render the threshold value and display a line chart showing the value for the last 30 intervals. This can provide an indication of recent values and their proximity to the threshold, and help you tune the clauses.

In this section, you will use the Kibana weblog sample dataset to setup and tune the conditions on an index threshold alert. For this example, we want to detect when any of our top three sites have served more than 420,000 bytes over a 24 hour period.

From the alert management UI, create a new alert, and fill in the general alert details. This alert will be checked every 4 hours, and will not execute actions more than once per day. Choose the index threshold alert type.

Click on each clause to open a control that helps you set the value:

The index clause control will list and allow you to search for available indices. Choose kibana_sample_data_logs

Once an index is selected, the list of time fields for that index will be available to select. Choose @timestamp.

We want to detect the number of bytes served during the time window, so we select sum as the aggregation, and bytes as the field to aggregate.

We want to alert on the three sites that have the most traffic, so we’ll group the sum of bytes by the host.keyword field and take the top 3 values.

We want to alert when any site exceeds 420,000 bytes over a 24 hour period, so we’ll set the threshold to 420,000 and use the is above comparison.

Finally, set the time window to 24 hours to complete the alert configuration.

The preview chart will render showing the 24 hour sum of bytes at 4 hours intervals (the check every interval) for the past 120 hours (the last 30 intervals).

You can interactively change the time window and observe the effect it has on the chart. Compare a 24 window to a 12 hour window. Notice the variability in the sum of bytes, due to different traffic levels during the day compared to at night. This variability would result in noisy alerts, so the 24 hour window is better. The preview chart can help you find the right values for your alert.