app/{vmagent,vminsert}/datadog: make the host label optional in DataDog data ingestion protocol

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3432

app/vmagent/datadog/request_handler.go

@@ -52,10 +52,12 @@ func insertRows(at *auth.Token, series []parser.Series, extraLabels []prompbmars
 			Name:  "__name__",
 			Value: ss.Metric,
 		})
-		labels = append(labels, prompbmarshal.Label{
-			Name:  "host",
-			Value: ss.Host,
-		})
+		if ss.Host != "" {
+			labels = append(labels, prompbmarshal.Label{
+				Name:  "host",
+				Value: ss.Host,
+			})
+		}
 		if ss.Device != "" {
 			labels = append(labels, prompbmarshal.Label{
 				Name:  "device",

app/vminsert/datadog/request_handler.go

@@ -54,7 +54,9 @@ func insertRows(series []parser.Series, extraLabels []prompbmarshal.Label) error
 		rowsTotal += len(ss.Points)
 		ctx.Labels = ctx.Labels[:0]
 		ctx.AddLabel("", ss.Metric)
-		ctx.AddLabel("host", ss.Host)
+		if ss.Host != "" {
+			ctx.AddLabel("host", ss.Host)
+		}
 		if ss.Device != "" {
 			ctx.AddLabel("device", ss.Device)
 		}

docs/CHANGELOG.md

@@ -54,6 +54,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): allow using `series_limit` option for [limiting the number of series a single scrape target generates](https://docs.victoriametrics.com/vmagent.html#cardinality-limiter) in [stream parsing mode](https://docs.victoriametrics.com/vmagent.html#stream-parsing-mode). See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3458).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): allow using `sample_limit` option for limiting the number of metrics a single scrape target can expose in every response sent over [stream parsing mode](https://docs.victoriametrics.com/vmagent.html#stream-parsing-mode).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add `exported_` prefix to metric names exported by scrape targets if these metric names clash with [automatically generated metrics](https://docs.victoriametrics.com/vmagent.html#automatically-generated-metrics) such as `up`, `scrape_samples_scraped`, etc. This prevents from corruption of automatically generated metrics. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3406).
+* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): make the `host` label optional in [DataDog data ingestion protocol](https://docs.victoriametrics.com/#how-to-send-data-from-datadog-agent). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3432).
 * FEATURE: [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html): improve error message when the requested path cannot be properly parsed, so users could identify the issue and properly fix the path. Now the error message links to [url format docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3402).
 * FEATURE: [VictoriaMetrics enterprise cluster](https://docs.victoriametrics.com/enterprise.html): add `-storageNode.discoveryInterval` command-line flag to `vmselect` and `vminsert` to control load on DNS servers when [automatic discovery of vmstorage nodes](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#automatic-vmstorage-discovery) is enabled. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3417).
 * FEATURE: [VictoriaMetrics enterprise cluster](https://docs.victoriametrics.com/enterprise.html): allow reading and updating the list of `vmstorage` nodes at `vmselect` and `vminsert` nodes via file. See [automatic discovery of vmstorage](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#automatic-vmstorage-discovery) for details.