feat: [inputs/burrow] fill more http transport parameters (#6948)

Co-authored-by: Sven Rebhan <36194019+srebhan@users.noreply.github.com>

plugins/inputs/burrow/burrow.go

@@ -3,6 +3,7 @@ package burrow
 import (
 	"encoding/json"
 	"fmt"
+	"net"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -168,11 +169,21 @@ func (b *burrow) createClient() (*http.Client, error) {
 		return nil, err
 	}
 
+	timeout := time.Duration(b.ResponseTimeout)
+	transport := http.Transport{
+		DialContext: &net.Dialer{Timeout: timeout, DualStack: true}.DialContext,
+		TLSClientConfig: tlsCfg,
+		// If b.ConcurrentConnections <= 1, then DefaultMaxIdleConnsPerHost is used (=2)
+		MaxIdleConnsPerHost: b.ConcurrentConnections / 2,
+		// If b.ConcurrentConnections == 0, then it is treated as "no limits"
+		MaxConnsPerHost: b.ConcurrentConnections,
+		ResponseHeaderTimeout: timeout,
+		IdleConnTimeout: 90*time.Second,
+	}
+
 	client := &http.Client{
-		Transport: &http.Transport{
-			TLSClientConfig: tlsCfg,
-		},
-		Timeout: time.Duration(b.ResponseTimeout),
+		Transport: &transport,
+		Timeout: timeout,
 	}
 
 	return client, nil