089_Heartbeats

Heartbeats

Wolverine can periodically emit a WolverineHeartbeat message from each running node so that external monitoring tools (for example CritterWatch) can detect when a node goes dark. Heartbeats are off by default and are opted-in through EnableHeartbeats.

Quickstart

using Wolverine;
 
await Host.CreateDefaultBuilder()
    .UseWolverine(opts =>
    {
        // Enable with the default 30-second cadence
        opts.EnableHeartbeats();
 
        // ...or override the interval
        // opts.EnableHeartbeats(TimeSpan.FromSeconds(10));
 
        // Route heartbeats wherever the dashboard listens. Without a publish
        // rule the heartbeat is local-only and does nothing if no in-process
        // handler subscribes.
        opts.PublishMessage<Wolverine.Runtime.Heartbeat.WolverineHeartbeat>()
            .ToRabbitExchange("monitoring");
    })
    .RunOasisAsync();

What gets sent

Each heartbeat carries the bare minimum a monitor needs to attribute it back to a node:

Field	Source
ServiceName	WolverineOptions.ServiceName
NodeNumber	WolverineOptions.Durability.AssignedNodeNumber
SentAt	UTC timestamp captured at publish
Uptime	Elapsed time since the heartbeat service started

The publish goes through Wolverine’s normal routing pipeline — apply PublishMessage, Publish().To*, or any other publish rule the same way you would for any application event.

Configuration

HeartbeatPolicy lives at WolverineOptions.Heartbeat:

opts.Heartbeat.Enabled = false;        // disable without removing registration
opts.Heartbeat.Interval = 5.Seconds(); // override the cadence

Enabled = false causes the hosted service to exit at startup, which is the recommended way to suppress heartbeats per environment (e.g. local development) without altering the registration.

Where this fits

Heartbeats answer “is this node still alive?” but say nothing about whether listeners or transports are healthy. Pair them with the existing durability and node health features for a fuller monitoring story.

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url: /guide/grpc/handlers.md