heartbeat_agg()

Create a liveness aggregate from a set of heartbeats

Since 1.15.0

Aggregate a set of heartbeat timestamps to track the liveness state of the underlying system for the specified time range.

Samples

Given a table called system_health with a ping_time column, construct an aggregate of system liveness for 10 days starting from Jan 1, 2022. This assumes a system is unhealthy if it hasn’t been heard from in a 5 minute window.

SELECT heartbeat_agg(
  ping_time,
  '01-01-2022 UTC',
  '10 days',
  '5 min')
FROM system_health;

Arguments

The syntax is:

heartbeat_agg(
    heartbeat TIMESTAMPTZ,
    agg_start TIMESTAMPTZ,
    agg_duration INTERVAL,
    heartbeat_liveness INTERVAL
) RETURNS HeartbeatAgg

Name	Type	Default	Required	Description
heartbeat	TIMESTAMPTZ	-	✔	The column containing the timestamps of the heartbeats
agg_start	TIMESTAMPTZ	-	✔	The start of the time range over which this aggregate is tracking liveness
agg_duration	INTERVAL	-	✔	The length of the time range over which this aggregate is tracking liveness. Any point in this range that doesn’t closely follow a heartbeat is considered to be dead
heartbeat_liveness	INTERVAL	-	✔	How long the system is considered to be live after each heartbeat

Returns

Column	Type	Description
heartbeat_agg	HeartbeatAgg	The liveness data for the heartbeated system over the provided interval.