VictoriaMetrics Stream Aggregation: Three-Year Review and Current Status (2026)

Tue, 12 May 2026 00:00:00 +0000

Introduction

It’s been exactly three years since the previous article Applying VictoriaMetrics Stream Aggregation for Metrics was published in March 2023. In these three years, the VictoriaMetrics ecosystem has undergone tremendous changes—let’s revisit the issues raised in that blog post, see what the official project has resolved, and where our stream-metrics-route project stands today.

I. Problems We Encountered Three Years Ago

Let’s quickly recap the core issue list from the 2023 blog post:

Applying VictoriaMetrics Stream Aggregation for Metrics

Mon, 27 Mar 2023 00:00:00 +0000

Community VM Stream Aggregation Capability Analysis and Issues

VictoriaMetrics Open-Source Project Native Capabilities

Stream aggregation in the VictoriaMetrics project was integrated into vmagent starting from version 1.86. For details, refer to: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3460 From the source code analysis, the stream aggregation capability looks like this:

The core computation code is described in the pushSample function:

go


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func (as *totalAggrState) pushSample(inputKey, outputKey string, value float64) {
	currentTime := fasttime.UnixTimestamp()
	deleteDeadline := currentTime + as.intervalSecs + (as.intervalSecs >> 1)
again:
	v, ok := as.m.Load(outputKey)
	if !ok {
		v = &totalStateValue{
			lastValues: make(map[string]*lastValueState),
		}
		vNew, loaded := as.m.LoadOrStore(outputKey, v)
		if loaded {
			v = vNew
		}
	}
	sv := v.(*totalStateValue)
	sv.mu.Lock()
	deleted := sv.deleted
	if !deleted {
		lv, ok := sv.lastValues[inputKey]
		if !ok {
			lv = &lastValueState{}
			sv.lastValues[inputKey] = lv
		}
		d := value
		if ok && lv.value <= value {
			d = value - lv.value
		}
		if ok || currentTime > as.ignoreInputDeadline {
			sv.total += d
		}
		lv.value = value
		lv.deleteDeadline = deleteDeadline
		sv.deleteDeadline = deleteDeadline
	}
	sv.mu.Unlock()
	if deleted {
		goto again
	}
}

General Application Analysis of Stream Aggregation

First, let’s look at the time series chart after stream aggregation: