forward samples in sequence

etc/server.conf

@@ -180,8 +180,8 @@ BasicAuthUser = ""
 # Basic auth password
 BasicAuthPass = ""
 # timeout settings, unit: ms
-Timeout = 30000
-DialTimeout = 10000
+Timeout = 10000
+DialTimeout = 3000
 TLSHandshakeTimeout = 30000
 ExpectContinueTimeout = 1000
 IdleConnTimeout = 90000

src/server/writer/writer.go

@@ -7,6 +7,7 @@ import (
 	"hash/crc32"
 	"net"
 	"net/http"
+	"sync"
 	"time"
 
 	"github.com/didi/nightingale/v5/src/server/config"
@@ -143,8 +144,23 @@ func (ws *WritersType) StartConsumer(index int, ch chan *prompb.TimeSeries) {
 // @Author: quzhihao
 func (ws *WritersType) post(index int, series []*prompb.TimeSeries) {
 	header := map[string]string{"hash": fmt.Sprintf("%s-%d", config.C.Heartbeat.Endpoint, index)}
-	for key := range ws.backends {
-		go ws.backends[key].Write(series, header)
+	if len(ws.backends) == 1 {
+		for key := range ws.backends {
+			ws.backends[key].Write(series, header)
+		}
+		return
+	}
+
+	if len(ws.backends) > 1 {
+		wg := new(sync.WaitGroup)
+		for key := range ws.backends {
+			wg.Add(1)
+			go func(wg *sync.WaitGroup, backend WriterType, items []*prompb.TimeSeries, header map[string]string) {
+				defer wg.Done()
+				backend.Write(series, header)
+			}(wg, ws.backends[key], series, header)
+		}
+		wg.Wait()
 	}
 }