Request priority

TL;DR. Pulse-Priority header propagates end-to-end on MDC, baggage, and outbound calls. Your load shedders can drop the right requests when the system is full.

When the system is overloaded, some requests matter more than others — checkout > recommendations, paid-tier > free, foreground > background. Without a priority signal you load-shed indiscriminately and drop the requests that pay the bills.

Pulse propagates a Pulse-Priority header end-to-end so your load shedders can drop the right requests, and your alerts can ignore noisy low-priority error bursts.

What you get

Your shedding logic becomes a one-liner:

if (RequestPriority.current().filter(p -> p == RequestPriority.LOW).isPresent()) {
    return Flux.empty();   // shed this request
}

Your error budget alerts can be scoped:

sum by (service) (rate(pulse_errors_unhandled_total{pulse_priority!="low"}[5m]))

Critical requests are also automatically escalated: when their timeout budget is exhausted, the corresponding log line goes out at WARN instead of INFO, so the on-call sees them faster.

Turn it on

On by default with the five-tier vocabulary (critical, high, normal, low, background). Callers just send Pulse-Priority: critical (or whichever tier). The vocabulary is fixed by design — bounded cardinality is the whole point — so Pulse won't accept arbitrary tier names.

To rename the inbound header, change the default tier when none is sent, or opt into priority as a metric tag on a curated allow-list of meters:

pulse:
  priority:
    header-name: Pulse-Priority      # default
    default-priority: normal         # default
    warn-on-critical-timeout-exhaustion: true   # default
    tag-meters: [http.server.requests]

What it adds

Where	Key
MDC	priority (Micrometer MDC key)
OTel baggage	pulse.priority
HTTP / Kafka outbound header	Pulse-Priority (configurable)
Thread-local accessor	RequestPriority.current()

When to skip it

If your platform already has a priority mechanism (Kubernetes PriorityClass, Envoy priority routing, gRPC metadata you trust):

pulse:
  priority:
    enabled: false

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Source: io.github.arun0009.pulse.priority · Status: Stable since 1.0.0