Fix influxdb output serialization on connection closed (#6621)

plugins/outputs/influxdb/http.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net"
 	"net/http"
 	"net/url"
@@ -288,7 +289,12 @@ func (c *httpClient) writeBatch(ctx context.Context, db string, metrics []telegr
 		return err
 	}
 
-	reader := influx.NewReader(metrics, c.config.Serializer)
+	reader, err := c.requestBodyReader(metrics)
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+
 	req, err := c.makeWriteRequest(url, reader)
 	if err != nil {
 		return err
@@ -386,12 +392,6 @@ func (c *httpClient) makeQueryRequest(query string) (*http.Request, error) {
 
 func (c *httpClient) makeWriteRequest(url string, body io.Reader) (*http.Request, error) {
 	var err error
-	if c.config.ContentEncoding == "gzip" {
-		body, err = internal.CompressWithGzip(body)
-		if err != nil {
-			return nil, err
-		}
-	}
 
 	req, err := http.NewRequest("POST", url, body)
 	if err != nil {
@@ -408,6 +408,23 @@ func (c *httpClient) makeWriteRequest(url string, body io.Reader) (*http.Request
 	return req, nil
 }
 
+// requestBodyReader warp io.Reader from influx.NewReader to io.ReadCloser, which is usefully to fast close the write
+// side of the connection in case of error
+func (c *httpClient) requestBodyReader(metrics []telegraf.Metric) (io.ReadCloser, error) {
+	reader := influx.NewReader(metrics, c.config.Serializer)
+
+	if c.config.ContentEncoding == "gzip" {
+		rc, err := internal.CompressWithGzip(reader)
+		if err != nil {
+			return nil, err
+		}
+
+		return rc, nil
+	}
+
+	return ioutil.NopCloser(reader), nil
+}
+
 func (c *httpClient) addHeaders(req *http.Request) {
 	if c.config.Username != "" || c.config.Password != "" {
 		req.SetBasicAuth(c.config.Username, c.config.Password)

plugins/outputs/influxdb/influxdb.go

@@ -57,8 +57,7 @@ type InfluxDB struct {
 	CreateHTTPClientF func(config *HTTPConfig) (Client, error)
 	CreateUDPClientF  func(config *UDPConfig) (Client, error)
 
-	serializer *influx.Serializer
-	Log        telegraf.Logger
+	Log telegraf.Logger
 }
 
 var sampleConfig = `
@@ -145,11 +144,6 @@ func (i *InfluxDB) Connect() error {
 		urls = append(urls, defaultURL)
 	}
 
-	i.serializer = influx.NewSerializer()
-	if i.InfluxUintSupport {
-		i.serializer.SetFieldTypeSupport(influx.UintSupport)
-	}
-
 	for _, u := range urls {
 		parts, err := url.Parse(u)
 		if err != nil {
@@ -237,7 +231,7 @@ func (i *InfluxDB) udpClient(url *url.URL) (Client, error) {
 	config := &UDPConfig{
 		URL:            url,
 		MaxPayloadSize: int(i.UDPPayload.Size),
-		Serializer:     i.serializer,
+		Serializer:     i.newSerializer(),
 		Log:            i.Log,
 	}
 
@@ -271,7 +265,7 @@ func (i *InfluxDB) httpClient(ctx context.Context, url *url.URL, proxy *url.URL)
 		SkipDatabaseCreation: i.SkipDatabaseCreation,
 		RetentionPolicy:      i.RetentionPolicy,
 		Consistency:          i.WriteConsistency,
-		Serializer:           i.serializer,
+		Serializer:           i.newSerializer(),
 		Log:                  i.Log,
 	}
 
@@ -291,6 +285,15 @@ func (i *InfluxDB) httpClient(ctx context.Context, url *url.URL, proxy *url.URL)
 	return c, nil
 }
 
+func (i *InfluxDB) newSerializer() *influx.Serializer {
+	serializer := influx.NewSerializer()
+	if i.InfluxUintSupport {
+		serializer.SetFieldTypeSupport(influx.UintSupport)
+	}
+
+	return serializer
+}
+
 func init() {
 	outputs.Add("influxdb", func() telegraf.Output {
 		return &InfluxDB{