Here is the trigger for [[Site UP-chart]]:

{{{#!Trigger:up_chart
type=periodic
period=hourly
start=2:15
action=load Site_UP-chart:birdcloud_s1
last_triggered=2026-10-07_18:10:03
last_status=OK : load executed OK
}}}

= Explanation =
A cron job on bird.org runs 'triggerd' periodically.  That program
checks all the pages in the wiki for trigger definitions, and
runs all the expired ones.  In this case, it causes a load of a particular
block on a page: block 'birdcloud_s1' on page [[Site_UP-chart]].

This is a snapshot definition block, and it, in turn loads the
value of the block: birdcloud_status, and puts the resulting value
into birdcloud_status_table.

From there a chart is made of the results.

= Bugs =
 * The SiteStatus macro sometimes gets exceptions, and puts those into the
   table, instead of the value 0.  It is missing a try/except clause somewhere.
 * There is no chart
 * The trigger was not firing to gather the data every hour
   * previously, the item name was incorrect, using just the block name 's1'
     instead of birdcloud_s1.  This was fixed on Sep 12.

Trigger help: [[UP-trigger?action=Trigger.help|Trigger help]]

{{Category(Features,Trigger)}}