http listener refactor

in this commit:

- chunks out the http request body to avoid making very large
  allocations.
- establishes a limit for the maximum http request body size that the
  listener will accept.
- utilizes a pool of byte buffers to reduce GC pressure.

internal/buffer/buffer.go

 package buffer
 
 import (
+	"sync"
+
 	"github.com/influxdata/telegraf"
 )
 
@@ -11,6 +13,8 @@ type Buffer struct {
 	drops int
 	// total metrics added
 	total int
+
+	sync.Mutex
 }
 
 // NewBuffer returns a Buffer
@@ -61,11 +65,13 @@ func (b *Buffer) Add(metrics ...telegraf.Metric) {
 // the batch will be of maximum length batchSize. It can be less than batchSize,
 // if the length of Buffer is less than batchSize.
 func (b *Buffer) Batch(batchSize int) []telegraf.Metric {
+	b.Lock()
 	n := min(len(b.buf), batchSize)
 	out := make([]telegraf.Metric, n)
 	for i := 0; i < n; i++ {
 		out[i] = <-b.buf
 	}
+	b.Unlock()
 	return out
 }
 

plugins/inputs/http_listener/bufferpool.go

+package http_listener
+
+import (
+	"sync/atomic"
+)
+
+type pool struct {
+	buffers chan []byte
+	size    int
+
+	created int64
+}
+
+// NewPool returns a new pool object.
+// n is the number of buffers
+// bufSize is the size (in bytes) of each buffer
+func NewPool(n, bufSize int) *pool {
+	return &pool{
+		buffers: make(chan []byte, n),
+		size:    bufSize,
+	}
+}
+
+func (p *pool) get() []byte {
+	select {
+	case b := <-p.buffers:
+		return b
+	default:
+		atomic.AddInt64(&p.created, 1)
+		return make([]byte, p.size)
+	}
+}
+
+func (p *pool) put(b []byte) {
+	select {
+	case p.buffers <- b:
+	default:
+	}
+}
+
+func (p *pool) ncreated() int64 {
+	return atomic.LoadInt64(&p.created)
+}

plugins/inputs/http_listener/http_listener.go

 package http_listener
 
 import (
-	"bufio"
 	"bytes"
-	"fmt"
+	"compress/gzip"
+	"io"
 	"log"
 	"net"
 	"net/http"
@@ -13,135 +13,138 @@ import (
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/plugins/inputs"
-	"github.com/influxdata/telegraf/plugins/inputs/http_listener/stoppableListener"
-	"github.com/influxdata/telegraf/plugins/parsers"
+	"github.com/influxdata/telegraf/plugins/parsers/influx"
+)
+
+const (
+	// DEFAULT_MAX_BODY_SIZE is the default maximum request body size, in bytes.
+	// if the request body is over this size, we will return an HTTP 413 error.
+	// 500 MB
+	DEFAULT_MAX_BODY_SIZE = 500 * 1024 * 1024
+
+	// MAX_LINE_SIZE is the maximum size, in bytes, that can be allocated for
+	// a single InfluxDB point.
+	// 64 KB
+	DEFAULT_MAX_LINE_SIZE = 64 * 1024
 )
 
 type HttpListener struct {
 	ServiceAddress string
 	ReadTimeout    internal.Duration
 	WriteTimeout   internal.Duration
+	MaxBodySize    int64
+	MaxLineSize    int
 
-	sync.Mutex
+	mu sync.Mutex
 	wg sync.WaitGroup
 
-	listener *stoppableListener.StoppableListener
+	listener net.Listener
 
-	parser parsers.Parser
+	parser influx.InfluxParser
 	acc    telegraf.Accumulator
+	pool   *pool
 }
 
 const sampleConfig = `
   ## Address and port to host HTTP listener on
   service_address = ":8186"
 
-  ## timeouts
+  ## maximum duration before timing out read of the request
   read_timeout = "10s"
+  ## maximum duration before timing out write of the response
   write_timeout = "10s"
+
+  ## Maximum allowed http request body size in bytes.
+  ## 0 means to use the default of 536,870,912 bytes (500 mebibytes)
+  max_body_size = 0
+
+  ## Maximum line size allowed to be sent in bytes.
+  ## 0 means to use the default of 65536 bytes (64 kibibytes)
+  max_line_size = 0
 `
 
-func (t *HttpListener) SampleConfig() string {
+func (h *HttpListener) SampleConfig() string {
 	return sampleConfig
 }
 
-func (t *HttpListener) Description() string {
+func (h *HttpListener) Description() string {
 	return "Influx HTTP write listener"
 }
 
-func (t *HttpListener) Gather(_ telegraf.Accumulator) error {
+func (h *HttpListener) Gather(_ telegraf.Accumulator) error {
+	log.Printf("D! The http_listener has created %d buffers", h.pool.ncreated())
 	return nil
 }
 
-func (t *HttpListener) SetParser(parser parsers.Parser) {
-	t.parser = parser
-}
-
 // Start starts the http listener service.
-func (t *HttpListener) Start(acc telegraf.Accumulator) error {
-	t.Lock()
-	defer t.Unlock()
+func (h *HttpListener) Start(acc telegraf.Accumulator) error {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	h.parser = influx.InfluxParser{}
 
-	t.acc = acc
-
-	var rawListener, err = net.Listen("tcp", t.ServiceAddress)
-	if err != nil {
-		return err
+	if h.MaxBodySize == 0 {
+		h.MaxBodySize = DEFAULT_MAX_BODY_SIZE
+	}
+	if h.MaxLineSize == 0 {
+		h.MaxLineSize = DEFAULT_MAX_LINE_SIZE
 	}
-	t.listener, err = stoppableListener.New(rawListener)
+
+	h.acc = acc
+	h.pool = NewPool(200, h.MaxLineSize)
+
+	var listener, err = net.Listen("tcp", h.ServiceAddress)
 	if err != nil {
 		return err
 	}
+	h.listener = listener
 
-	go t.httpListen()
+	h.wg.Add(1)
+	go func() {
+		defer h.wg.Done()
+		h.httpListen()
+	}()
 
-	log.Printf("I! Started HTTP listener service on %s\n", t.ServiceAddress)
+	log.Printf("I! Started HTTP listener service on %s\n", h.ServiceAddress)
 
 	return nil
 }
 
 // Stop cleans up all resources
-func (t *HttpListener) Stop() {
-	t.Lock()
-	defer t.Unlock()
-
-	t.listener.Stop()
-	t.listener.Close()
+func (h *HttpListener) Stop() {
+	h.mu.Lock()
+	defer h.mu.Unlock()
 
-	t.wg.Wait()
+	h.listener.Close()
+	h.wg.Wait()
 
-	log.Println("I! Stopped HTTP listener service on ", t.ServiceAddress)
+	log.Println("I! Stopped HTTP listener service on ", h.ServiceAddress)
 }
 
-// httpListen listens for HTTP requests.
-func (t *HttpListener) httpListen() error {
-	if t.ReadTimeout.Duration < time.Second {
-		t.ReadTimeout.Duration = time.Second * 10
+// httpListen sets up an http.Server and calls server.Serve.
+// like server.Serve, httpListen will always return a non-nil error, for this
+// reason, the error returned should probably be ignored.
+// see https://golang.org/pkg/net/http/#Server.Serve
+func (h *HttpListener) httpListen() error {
+	if h.ReadTimeout.Duration < time.Second {
+		h.ReadTimeout.Duration = time.Second * 10
 	}
-	if t.WriteTimeout.Duration < time.Second {
-		t.WriteTimeout.Duration = time.Second * 10
+	if h.WriteTimeout.Duration < time.Second {
+		h.WriteTimeout.Duration = time.Second * 10
 	}
 
 	var server = http.Server{
-		Handler:      t,
-		ReadTimeout:  t.ReadTimeout.Duration,
-		WriteTimeout: t.WriteTimeout.Duration,
+		Handler:      h,
+		ReadTimeout:  h.ReadTimeout.Duration,
+		WriteTimeout: h.WriteTimeout.Duration,
 	}
 
-	return server.Serve(t.listener)
+	return server.Serve(h.listener)
 }
 
-func (t *HttpListener) ServeHTTP(res http.ResponseWriter, req *http.Request) {
-	t.wg.Add(1)
-	defer t.wg.Done()
-
+func (h *HttpListener) ServeHTTP(res http.ResponseWriter, req *http.Request) {
 	switch req.URL.Path {
 	case "/write":
-		var http400msg bytes.Buffer
-		var partial string
-		scanner := bufio.NewScanner(req.Body)
-		scanner.Buffer([]byte(""), 128*1024)
-		for scanner.Scan() {
-			metrics, err := t.parser.Parse(scanner.Bytes())
-			if err == nil {
-				for _, m := range metrics {
-					t.acc.AddFields(m.Name(), m.Fields(), m.Tags(), m.Time())
-				}
-				partial = "partial write: "
-			} else {
-				http400msg.WriteString(err.Error() + " ")
-			}
-		}
-
-		if err := scanner.Err(); err != nil {
-			http.Error(res, "Internal server error: "+err.Error(), http.StatusInternalServerError)
-		} else if http400msg.Len() > 0 {
-			res.Header().Set("Content-Type", "application/json")
-			res.Header().Set("X-Influxdb-Version", "1.0")
-			res.WriteHeader(http.StatusBadRequest)
-			res.Write([]byte(fmt.Sprintf(`{"error":"%s%s"}`, partial, http400msg.String())))
-		} else {
-			res.WriteHeader(http.StatusNoContent)
-		}
+		h.serveWrite(res, req)
 	case "/query":
 		// Deliver a dummy response to the query endpoint, as some InfluxDB
 		// clients test endpoint availability with a query
@@ -158,8 +161,134 @@ func (t *HttpListener) ServeHTTP(res http.ResponseWriter, req *http.Request) {
 	}
 }
 
+func (h *HttpListener) serveWrite(res http.ResponseWriter, req *http.Request) {
+	// Check that the content length is not too large for us to handle.
+	if req.ContentLength > h.MaxBodySize {
+		tooLarge(res)
+		return
+	}
+	now := time.Now()
+
+	// Handle gzip request bodies
+	body := req.Body
+	if req.Header.Get("Content-Encoding") == "gzip" {
+		body, err := gzip.NewReader(req.Body)
+		defer body.Close()
+		if err != nil {
+			log.Println("E! " + err.Error())
+			badRequest(res)
+			return
+		}
+	}
+	body = http.MaxBytesReader(res, body, h.MaxBodySize)
+
+	var return400 bool
+	var hangingBytes bool
+	buf := h.pool.get()
+	defer func() { h.pool.put(buf) }()
+	bufStart := 0
+	for {
+		n, err := io.ReadFull(body, buf[bufStart:])
+		if err != nil && err != io.ErrUnexpectedEOF && err != io.EOF {
+			log.Println("E! " + err.Error())
+			// problem reading the request body
+			badRequest(res)
+			return
+		}
+
+		if err == io.EOF {
+			if return400 {
+				badRequest(res)
+			} else {
+				res.WriteHeader(http.StatusNoContent)
+			}
+			return
+		}
+
+		if hangingBytes {
+			i := bytes.IndexByte(buf, '\n')
+			if i == -1 {
+				// still didn't find a newline, keep scanning
+				continue
+			}
+			// rotate the bit remaining after the first newline to the front of the buffer
+			i++ // start copying after the newline
+			bufStart = len(buf) - i
+			if bufStart > 0 {
+				copy(buf, buf[i:])
+			}
+			hangingBytes = false
+			continue
+		}
+
+		if err == io.ErrUnexpectedEOF {
+			// finished reading the request body
+			if err := h.parse(buf[:n+bufStart], now); err != nil {
+				log.Println("E! " + err.Error())
+				return400 = true
+			}
+			if return400 {
+				badRequest(res)
+			} else {
+				res.WriteHeader(http.StatusNoContent)
+			}
+			return
+		}
+
+		// if we got down here it means that we filled our buffer, and there
+		// are still bytes remaining to be read. So we will parse up until the
+		// final newline, then push the rest of the bytes into the next buffer.
+		i := bytes.LastIndexByte(buf, '\n')
+		if i == -1 {
+			// drop any line longer than the max buffer size
+			log.Printf("E! http_listener received a single line longer than the maximum of %d bytes",
+				len(buf))
+			hangingBytes = true
+			return400 = true
+			bufStart = 0
+			continue
+		}
+		if err := h.parse(buf[:i], now); err != nil {
+			log.Println("E! " + err.Error())
+			return400 = true
+		}
+		// rotate the bit remaining after the last newline to the front of the buffer
+		i++ // start copying after the newline
+		bufStart = len(buf) - i
+		if bufStart > 0 {
+			copy(buf, buf[i:])
+		}
+	}
+}
+
+func (h *HttpListener) parse(b []byte, t time.Time) error {
+	metrics, err := h.parser.ParseWithDefaultTime(b, t)
+
+	for _, m := range metrics {
+		h.acc.AddFields(m.Name(), m.Fields(), m.Tags(), m.Time())
+	}
+
+	return err
+}
+
+func tooLarge(res http.ResponseWriter) {
+	res.Header().Set("Content-Type", "application/json")
+	res.Header().Set("X-Influxdb-Version", "1.0")
+	res.WriteHeader(http.StatusRequestEntityTooLarge)
+	res.Write([]byte(`{"error":"http: request body too large"}`))
+}
+
+func badRequest(res http.ResponseWriter) {
+	res.Header().Set("Content-Type", "application/json")
+	res.Header().Set("X-Influxdb-Version", "1.0")
+	res.WriteHeader(http.StatusBadRequest)
+	res.Write([]byte(`{"error":"http: bad request"}`))
+}
+
 func init() {
 	inputs.Add("http_listener", func() telegraf.Input {
-		return &HttpListener{}
+		return &HttpListener{
+			ServiceAddress: ":8186",
+		}
 	})
 }

plugins/inputs/http_listener/http_listener_test.go

 package http_listener
 
 import (
+	"bytes"
+	"net/http"
 	"sync"
 	"testing"
 	"time"
 
-	"github.com/influxdata/telegraf/plugins/parsers"
 	"github.com/influxdata/telegraf/testutil"
 
-	"bytes"
 	"github.com/stretchr/testify/require"
-	"net/http"
 )
 
 const (
@@ -36,8 +35,6 @@ func newTestHttpListener() *HttpListener {
 
 func TestWriteHTTP(t *testing.T) {
 	listener := newTestHttpListener()
-	parser, _ := parsers.NewInfluxParser()
-	listener.SetParser(parser)
 
 	acc := &testutil.Accumulator{}
 	require.NoError(t, listener.Start(acc))
@@ -71,10 +68,10 @@ func TestWriteHTTP(t *testing.T) {
 		)
 	}
 
-	// Post a gigantic metric to the listener:
+	// Post a gigantic metric to the listener and verify that an error is returned:
 	resp, err = http.Post("http://localhost:8186/write?db=mydb", "", bytes.NewBuffer([]byte(hugeMetric)))
 	require.NoError(t, err)
-	require.EqualValues(t, 204, resp.StatusCode)
+	require.EqualValues(t, 400, resp.StatusCode)
 
 	time.Sleep(time.Millisecond * 15)
 	acc.AssertContainsTaggedFields(t, "cpu_load_short",
@@ -83,11 +80,27 @@ func TestWriteHTTP(t *testing.T) {
 	)
 }
 
+func TestWriteHTTPMaxLineSizeIncrease(t *testing.T) {
+	listener := &HttpListener{
+		ServiceAddress: ":8296",
+		MaxLineSize:    128 * 1000,
+	}
+
+	acc := &testutil.Accumulator{}
+	require.NoError(t, listener.Start(acc))
+	defer listener.Stop()
+
+	time.Sleep(time.Millisecond * 25)
+
+	// Post a gigantic metric to the listener and verify that an error is returned:
+	resp, err := http.Post("http://localhost:8296/write?db=mydb", "", bytes.NewBuffer([]byte(hugeMetric)))
+	require.NoError(t, err)
+	require.EqualValues(t, 204, resp.StatusCode)
+}
+
 // writes 25,000 metrics to the listener with 10 different writers
 func TestWriteHTTPHighTraffic(t *testing.T) {
 	listener := &HttpListener{ServiceAddress: ":8286"}
-	parser, _ := parsers.NewInfluxParser()
-	listener.SetParser(parser)
 
 	acc := &testutil.Accumulator{}
 	require.NoError(t, listener.Start(acc))
@@ -118,7 +131,6 @@ func TestWriteHTTPHighTraffic(t *testing.T) {
 
 func TestReceive404ForInvalidEndpoint(t *testing.T) {
 	listener := newTestHttpListener()
-	listener.parser, _ = parsers.NewInfluxParser()
 
 	acc := &testutil.Accumulator{}
 	require.NoError(t, listener.Start(acc))
@@ -136,7 +148,6 @@ func TestWriteHTTPInvalid(t *testing.T) {
 	time.Sleep(time.Millisecond * 250)
 
 	listener := newTestHttpListener()
-	listener.parser, _ = parsers.NewInfluxParser()
 
 	acc := &testutil.Accumulator{}
 	require.NoError(t, listener.Start(acc))
@@ -154,7 +165,6 @@ func TestWriteHTTPEmpty(t *testing.T) {
 	time.Sleep(time.Millisecond * 250)
 
 	listener := newTestHttpListener()
-	listener.parser, _ = parsers.NewInfluxParser()
 
 	acc := &testutil.Accumulator{}
 	require.NoError(t, listener.Start(acc))
@@ -172,7 +182,6 @@ func TestQueryAndPingHTTP(t *testing.T) {
 	time.Sleep(time.Millisecond * 250)
 
 	listener := newTestHttpListener()
-	listener.parser, _ = parsers.NewInfluxParser()
 
 	acc := &testutil.Accumulator{}
 	require.NoError(t, listener.Start(acc))

plugins/inputs/http_listener/stoppableListener/LICENSE

-Copyright (c) 2014, Eric Urban
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
-
-1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
-
-2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

plugins/inputs/http_listener/stoppableListener/listener.go

-package stoppableListener
-
-import (
-	"errors"
-	"net"
-	"time"
-)
-
-type StoppableListener struct {
-	*net.TCPListener          //Wrapped listener
-	stop             chan int //Channel used only to indicate listener should shutdown
-}
-
-func New(l net.Listener) (*StoppableListener, error) {
-	tcpL, ok := l.(*net.TCPListener)
-
-	if !ok {
-		return nil, errors.New("Cannot wrap listener")
-	}
-
-	retval := &StoppableListener{}
-	retval.TCPListener = tcpL
-	retval.stop = make(chan int)
-
-	return retval, nil
-}
-
-var StoppedError = errors.New("Listener stopped")
-
-func (sl *StoppableListener) Accept() (net.Conn, error) {
-
-	for {
-		//Wait up to one second for a new connection
-		sl.SetDeadline(time.Now().Add(time.Second))
-
-		newConn, err := sl.TCPListener.Accept()
-
-		//Check for the channel being closed
-		select {
-		case <-sl.stop:
-			return nil, StoppedError
-		default:
-			//If the channel is still open, continue as normal
-		}
-
-		if err != nil {
-			netErr, ok := err.(net.Error)
-
-			//If this is a timeout, then continue to wait for
-			//new connections
-			if ok && netErr.Timeout() && netErr.Temporary() {
-				continue
-			}
-		}
-
-		return newConn, err
-	}
-}
-
-func (sl *StoppableListener) Stop() {
-	close(sl.stop)
-}

plugins/parsers/influx/parser.go

@@ -3,6 +3,7 @@ package influx
 import (
 	"bytes"
 	"fmt"
+	"time"
 
 	"github.com/influxdata/telegraf"
 
@@ -15,15 +16,10 @@ type InfluxParser struct {
 	DefaultTags map[string]string
 }
 
-// Parse returns a slice of Metrics from a text representation of a
-// metric (in line-protocol format)
-// with each metric separated by newlines. If any metrics fail to parse,
-// a non-nil error will be returned in addition to the metrics that parsed
-// successfully.
-func (p *InfluxParser) Parse(buf []byte) ([]telegraf.Metric, error) {
+func (p *InfluxParser) ParseWithDefaultTime(buf []byte, t time.Time) ([]telegraf.Metric, error) {
 	// parse even if the buffer begins with a newline
 	buf = bytes.TrimPrefix(buf, []byte("\n"))
-	points, err := models.ParsePoints(buf)
+	points, err := models.ParsePointsWithPrecision(buf, t, "n")
 	metrics := make([]telegraf.Metric, len(points))
 	for i, point := range points {
 		for k, v := range p.DefaultTags {
@@ -39,6 +35,15 @@ func (p *InfluxParser) Parse(buf []byte) ([]telegraf.Metric, error) {
 	return metrics, err
 }
 
+// Parse returns a slice of Metrics from a text representation of a
+// metric (in line-protocol format)
+// with each metric separated by newlines. If any metrics fail to parse,
+// a non-nil error will be returned in addition to the metrics that parsed
+// successfully.
+func (p *InfluxParser) Parse(buf []byte) ([]telegraf.Metric, error) {
+	return p.ParseWithDefaultTime(buf, time.Now())
+}
+
 func (p *InfluxParser) ParseLine(line string) (telegraf.Metric, error) {
 	metrics, err := p.Parse([]byte(line + "\n"))