Heartbeat monitoring
A monitoring approach that watches for a steady cadence of expected events and alerts when the rhythm breaks. Borrowed from infrastructure monitoring; surprisingly useful for high-volume email flows.
Definition
What heartbeat monitoring is
Heartbeat monitoring is the inverse of single-event monitoring. Instead of asking "did this specific message arrive on time", it asks "is the rhythm of messages I expect still happening". The term comes from infrastructure: a server emits a heartbeat signal at a fixed interval, and the monitor pages someone when the heartbeat stops. The check is on the cadence, not on any individual signal.
In email, heartbeat monitoring is the right tool for flows where the per-message volume is high enough that a single missed send is noise, but a sudden silence is meaningful. Order confirmation emails for a busy storefront might fire fifty times an hour during peak. The right alert is not "this specific confirmation did not arrive". It is "no confirmation has fired in the last twenty minutes during a window where the volume baseline is fifty an hour".
When to use it
Heartbeat versus per-send arrival monitoring
Use heartbeat for high-volume flows
Order confirmations, shipping updates, lifecycle drips with steady throughput. Volume is high enough that a per-send check would be noisy, but rhythm matters.
Use per-send arrival for transactional
Password resets, account confirmations, two-factor codes. One missing send is one customer locked out. Per-send arrival window monitoring is the right tool.
Use both for revenue-critical flows
Abandoned cart, checkout flows. Per-send to catch the high-cost individual failure, heartbeat to catch the systemic outage.
How it works in Telltide
Cadence-aware alerts on a per-monitor basis
A Telltide heartbeat monitor learns the expected volume and timing of a flow over a baseline period. Once the baseline is established, the monitor alerts when the rhythm deviates beyond a configured tolerance: a sudden gap, a sudden burst, or a steady decline below baseline. The flow can be running on any platform: Klaviyo, Salesforce Marketing Cloud, HubSpot, or anywhere else. Telltide is platform-agnostic on the inbox.
Related reading
Concepts that travel together
- Silent send: the failure heartbeat monitoring is most often defending against.
- Triggered flow: the surface heartbeat monitoring is usually applied to.
- Transactional email monitoring: where per-send arrival, not heartbeat, is the right approach.
- Lifecycle email monitoring: long-cycle flows where heartbeat is often a better fit.
From the blog
Cadence as a health signal
- 25 hours of silence: how a sustained drop in inbox cadence is the earliest signal of an upstream incident.
- CRM journey observability: where heartbeat sits in the broader observability picture.
Watch your flows from the inbox
One monitor free. Paid plans from $49 USD per month.