Compute the availability history

An example query to compute the availability history for a link.

In order to achieve a reliable availability, it is recommended to enable the Track availability feature on the desired link.

Start from the link_events data source, filtered by source and destination ip in order to precisely identify the target link. Consider also filtering by protocol to achieve a higher degree of precision.
link_events | where id_src == 10.254.3.9 | where id_dst == 172.31.50.2
The next step is to sort the events by ascending time of creation. Without this step the availability_history might produce meaningless results, such as negative values. Then, to compute the availability_history with a bucket of 1 minute (60000 milliseconds), you can complete query is as follows:
link_events | where id_src == 10.254.3.9 | where id_dst == 172.31.50.2 | sort time asc | availability_history 60000
Figure 1. Availability history example

Availability history example

Note: By default, link_events generation is disabled. To enable it, you can use the configuration rule described in Configure links.