app/vmctl: Allow vmnative exports to skip HTTP keepalive. (#3909)

app/vmctl: support HTTP keepalive disabling for vm-native mode

app/vmctl/flags.go

@@ -325,6 +325,8 @@ const (
 	vmNativeFilterTimeEnd   = "vm-native-filter-time-end"
 	vmNativeStepInterval    = "vm-native-step-interval"
 
+	vmNativeDisableHTTPKeepAlive = "vm-native-disable-http-keep-alive"
+
 	vmNativeSrcAddr     = "vm-native-src-addr"
 	vmNativeSrcUser     = "vm-native-src-user"
 	vmNativeSrcPassword = "vm-native-src-password"
@@ -358,6 +360,11 @@ var (
 			Name:  vmNativeStepInterval,
 			Usage: fmt.Sprintf("Split export data into chunks. Requires setting --%s. Valid values are '%s','%s','%s','%s'.", vmNativeFilterTimeStart, stepper.StepMonth, stepper.StepDay, stepper.StepHour, stepper.StepMinute),
 		},
+		&cli.BoolFlag{
+			Name:  vmNativeDisableHTTPKeepAlive,
+			Usage: "Disable HTTP persistent connections for requests made to VictoriaMetrics components during export",
+			Value: false,
+		},
 		&cli.StringFlag{
 			Name: vmNativeSrcAddr,
 			Usage: "VictoriaMetrics address to perform export from. \n" +

app/vmctl/main.go

@@ -209,17 +209,19 @@ func main() {
 							Chunk:     c.String(vmNativeStepInterval),
 						},
 						src: &native.Client{
-							Addr:     strings.Trim(c.String(vmNativeSrcAddr), "/"),
-							User:     c.String(vmNativeSrcUser),
-							Password: c.String(vmNativeSrcPassword),
-							Headers:  c.String(vmNativeSrcHeaders),
+							Addr:                 strings.Trim(c.String(vmNativeSrcAddr), "/"),
+							User:                 c.String(vmNativeSrcUser),
+							Password:             c.String(vmNativeSrcPassword),
+							Headers:              c.String(vmNativeSrcHeaders),
+							DisableHTTPKeepAlive: c.Bool(vmNativeDisableHTTPKeepAlive),
 						},
 						dst: &native.Client{
-							Addr:        strings.Trim(c.String(vmNativeDstAddr), "/"),
-							User:        c.String(vmNativeDstUser),
-							Password:    c.String(vmNativeDstPassword),
-							ExtraLabels: c.StringSlice(vmExtraLabel),
-							Headers:     c.String(vmNativeDstHeaders),
+							Addr:                 strings.Trim(c.String(vmNativeDstAddr), "/"),
+							User:                 c.String(vmNativeDstUser),
+							Password:             c.String(vmNativeDstPassword),
+							ExtraLabels:          c.StringSlice(vmExtraLabel),
+							Headers:              c.String(vmNativeDstHeaders),
+							DisableHTTPKeepAlive: c.Bool(vmNativeDisableHTTPKeepAlive),
 						},
 						backoff: backoff.New(),
 						cc:      c.Int(vmConcurrency),

app/vmctl/native/client.go

@@ -18,11 +18,12 @@ const (
 // Client is an HTTP client for exporting and importing
 // time series via native protocol.
 type Client struct {
-	Addr        string
-	User        string
-	Password    string
-	ExtraLabels []string
-	Headers     string
+	Addr                 string
+	User                 string
+	Password             string
+	ExtraLabels          []string
+	Headers              string
+	DisableHTTPKeepAlive bool
 }
 
 // LabelValues represents series from api/v1/series response
@@ -196,7 +197,8 @@ func (c *Client) do(req *http.Request, expSC int) (*http.Response, error) {
 	if c.User != "" {
 		req.SetBasicAuth(c.User, c.Password)
 	}
-	resp, err := http.DefaultClient.Do(req)
+	var httpClient = &http.Client{Transport: &http.Transport{DisableKeepAlives: c.DisableHTTPKeepAlive}}
+	resp, err := httpClient.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("unexpected error when performing request: %w", err)
 	}