forked from mirror/client_golang
Merge pull request #482 from prometheus/beorn7/http
Use gzip from a pool and stream while encoding metrics
This commit is contained in:
commit
16f375c74d
|
@ -15,9 +15,7 @@ package prometheus
|
||||||
|
|
||||||
import (
|
import (
|
||||||
"bufio"
|
"bufio"
|
||||||
"bytes"
|
|
||||||
"compress/gzip"
|
"compress/gzip"
|
||||||
"fmt"
|
|
||||||
"io"
|
"io"
|
||||||
"net"
|
"net"
|
||||||
"net/http"
|
"net/http"
|
||||||
|
@ -41,19 +39,10 @@ const (
|
||||||
acceptEncodingHeader = "Accept-Encoding"
|
acceptEncodingHeader = "Accept-Encoding"
|
||||||
)
|
)
|
||||||
|
|
||||||
var bufPool sync.Pool
|
var gzipPool = sync.Pool{
|
||||||
|
New: func() interface{} {
|
||||||
func getBuf() *bytes.Buffer {
|
return gzip.NewWriter(nil)
|
||||||
buf := bufPool.Get()
|
},
|
||||||
if buf == nil {
|
|
||||||
return &bytes.Buffer{}
|
|
||||||
}
|
|
||||||
return buf.(*bytes.Buffer)
|
|
||||||
}
|
|
||||||
|
|
||||||
func giveBuf(buf *bytes.Buffer) {
|
|
||||||
buf.Reset()
|
|
||||||
bufPool.Put(buf)
|
|
||||||
}
|
}
|
||||||
|
|
||||||
// Handler returns an HTTP handler for the DefaultGatherer. It is
|
// Handler returns an HTTP handler for the DefaultGatherer. It is
|
||||||
|
@ -71,56 +60,38 @@ func Handler() http.Handler {
|
||||||
// Deprecated: Use promhttp.HandlerFor(DefaultGatherer, promhttp.HandlerOpts{})
|
// Deprecated: Use promhttp.HandlerFor(DefaultGatherer, promhttp.HandlerOpts{})
|
||||||
// instead. See there for further documentation.
|
// instead. See there for further documentation.
|
||||||
func UninstrumentedHandler() http.Handler {
|
func UninstrumentedHandler() http.Handler {
|
||||||
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
|
return http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
|
||||||
mfs, err := DefaultGatherer.Gather()
|
mfs, err := DefaultGatherer.Gather()
|
||||||
if err != nil {
|
if err != nil {
|
||||||
http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError)
|
httpError(rsp, err)
|
||||||
return
|
return
|
||||||
}
|
}
|
||||||
|
|
||||||
contentType := expfmt.Negotiate(req.Header)
|
contentType := expfmt.Negotiate(req.Header)
|
||||||
buf := getBuf()
|
header := rsp.Header()
|
||||||
defer giveBuf(buf)
|
|
||||||
writer, encoding := decorateWriter(req, buf)
|
|
||||||
enc := expfmt.NewEncoder(writer, contentType)
|
|
||||||
var lastErr error
|
|
||||||
for _, mf := range mfs {
|
|
||||||
if err := enc.Encode(mf); err != nil {
|
|
||||||
lastErr = err
|
|
||||||
http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
|
|
||||||
return
|
|
||||||
}
|
|
||||||
}
|
|
||||||
if closer, ok := writer.(io.Closer); ok {
|
|
||||||
closer.Close()
|
|
||||||
}
|
|
||||||
if lastErr != nil && buf.Len() == 0 {
|
|
||||||
http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
|
|
||||||
return
|
|
||||||
}
|
|
||||||
header := w.Header()
|
|
||||||
header.Set(contentTypeHeader, string(contentType))
|
header.Set(contentTypeHeader, string(contentType))
|
||||||
header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
|
|
||||||
if encoding != "" {
|
w := io.Writer(rsp)
|
||||||
header.Set(contentEncodingHeader, encoding)
|
if gzipAccepted(req.Header) {
|
||||||
}
|
header.Set(contentEncodingHeader, "gzip")
|
||||||
w.Write(buf.Bytes())
|
gz := gzipPool.Get().(*gzip.Writer)
|
||||||
})
|
defer gzipPool.Put(gz)
|
||||||
|
|
||||||
|
gz.Reset(w)
|
||||||
|
defer gz.Close()
|
||||||
|
|
||||||
|
w = gz
|
||||||
}
|
}
|
||||||
|
|
||||||
// decorateWriter wraps a writer to handle gzip compression if requested. It
|
enc := expfmt.NewEncoder(w, contentType)
|
||||||
// returns the decorated writer and the appropriate "Content-Encoding" header
|
|
||||||
// (which is empty if no compression is enabled).
|
for _, mf := range mfs {
|
||||||
func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
|
if err := enc.Encode(mf); err != nil {
|
||||||
header := request.Header.Get(acceptEncodingHeader)
|
httpError(rsp, err)
|
||||||
parts := strings.Split(header, ",")
|
return
|
||||||
for _, part := range parts {
|
|
||||||
part = strings.TrimSpace(part)
|
|
||||||
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
|
|
||||||
return gzip.NewWriter(writer), "gzip"
|
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
return writer, ""
|
})
|
||||||
}
|
}
|
||||||
|
|
||||||
var instLabels = []string{"method", "code"}
|
var instLabels = []string{"method", "code"}
|
||||||
|
@ -503,3 +474,31 @@ func sanitizeCode(s int) string {
|
||||||
return strconv.Itoa(s)
|
return strconv.Itoa(s)
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// gzipAccepted returns whether the client will accept gzip-encoded content.
|
||||||
|
func gzipAccepted(header http.Header) bool {
|
||||||
|
a := header.Get(acceptEncodingHeader)
|
||||||
|
parts := strings.Split(a, ",")
|
||||||
|
for _, part := range parts {
|
||||||
|
part = strings.TrimSpace(part)
|
||||||
|
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return false
|
||||||
|
}
|
||||||
|
|
||||||
|
// httpError removes any content-encoding header and then calls http.Error with
|
||||||
|
// the provided error and http.StatusInternalServerErrer. Error contents is
|
||||||
|
// supposed to be uncompressed plain text. However, same as with a plain
|
||||||
|
// http.Error, any header settings will be void if the header has already been
|
||||||
|
// sent. The error message will still be written to the writer, but it will
|
||||||
|
// probably be of limited use.
|
||||||
|
func httpError(rsp http.ResponseWriter, err error) {
|
||||||
|
rsp.Header().Del(contentEncodingHeader)
|
||||||
|
http.Error(
|
||||||
|
rsp,
|
||||||
|
"An error has occurred while serving metrics:\n\n"+err.Error(),
|
||||||
|
http.StatusInternalServerError,
|
||||||
|
)
|
||||||
|
}
|
||||||
|
|
|
@ -32,7 +32,6 @@
|
||||||
package promhttp
|
package promhttp
|
||||||
|
|
||||||
import (
|
import (
|
||||||
"bytes"
|
|
||||||
"compress/gzip"
|
"compress/gzip"
|
||||||
"fmt"
|
"fmt"
|
||||||
"io"
|
"io"
|
||||||
|
@ -53,19 +52,10 @@ const (
|
||||||
acceptEncodingHeader = "Accept-Encoding"
|
acceptEncodingHeader = "Accept-Encoding"
|
||||||
)
|
)
|
||||||
|
|
||||||
var bufPool sync.Pool
|
var gzipPool = sync.Pool{
|
||||||
|
New: func() interface{} {
|
||||||
func getBuf() *bytes.Buffer {
|
return gzip.NewWriter(nil)
|
||||||
buf := bufPool.Get()
|
},
|
||||||
if buf == nil {
|
|
||||||
return &bytes.Buffer{}
|
|
||||||
}
|
|
||||||
return buf.(*bytes.Buffer)
|
|
||||||
}
|
|
||||||
|
|
||||||
func giveBuf(buf *bytes.Buffer) {
|
|
||||||
buf.Reset()
|
|
||||||
bufPool.Put(buf)
|
|
||||||
}
|
}
|
||||||
|
|
||||||
// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
|
// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
|
||||||
|
@ -100,19 +90,18 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
|
||||||
inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
|
inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
|
||||||
}
|
}
|
||||||
|
|
||||||
h := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
|
h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
|
||||||
if inFlightSem != nil {
|
if inFlightSem != nil {
|
||||||
select {
|
select {
|
||||||
case inFlightSem <- struct{}{}: // All good, carry on.
|
case inFlightSem <- struct{}{}: // All good, carry on.
|
||||||
defer func() { <-inFlightSem }()
|
defer func() { <-inFlightSem }()
|
||||||
default:
|
default:
|
||||||
http.Error(w, fmt.Sprintf(
|
http.Error(rsp, fmt.Sprintf(
|
||||||
"Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
|
"Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
|
||||||
), http.StatusServiceUnavailable)
|
), http.StatusServiceUnavailable)
|
||||||
return
|
return
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
mfs, err := reg.Gather()
|
mfs, err := reg.Gather()
|
||||||
if err != nil {
|
if err != nil {
|
||||||
if opts.ErrorLog != nil {
|
if opts.ErrorLog != nil {
|
||||||
|
@ -123,26 +112,40 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
|
||||||
panic(err)
|
panic(err)
|
||||||
case ContinueOnError:
|
case ContinueOnError:
|
||||||
if len(mfs) == 0 {
|
if len(mfs) == 0 {
|
||||||
http.Error(w, "No metrics gathered, last error:\n\n"+err.Error(), http.StatusInternalServerError)
|
// Still report the error if no metrics have been gathered.
|
||||||
|
httpError(rsp, err)
|
||||||
return
|
return
|
||||||
}
|
}
|
||||||
case HTTPErrorOnError:
|
case HTTPErrorOnError:
|
||||||
http.Error(w, "An error has occurred during metrics gathering:\n\n"+err.Error(), http.StatusInternalServerError)
|
httpError(rsp, err)
|
||||||
return
|
return
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
contentType := expfmt.Negotiate(req.Header)
|
contentType := expfmt.Negotiate(req.Header)
|
||||||
buf := getBuf()
|
header := rsp.Header()
|
||||||
defer giveBuf(buf)
|
header.Set(contentTypeHeader, string(contentType))
|
||||||
writer, encoding := decorateWriter(req, buf, opts.DisableCompression)
|
|
||||||
enc := expfmt.NewEncoder(writer, contentType)
|
w := io.Writer(rsp)
|
||||||
|
if !opts.DisableCompression && gzipAccepted(req.Header) {
|
||||||
|
header.Set(contentEncodingHeader, "gzip")
|
||||||
|
gz := gzipPool.Get().(*gzip.Writer)
|
||||||
|
defer gzipPool.Put(gz)
|
||||||
|
|
||||||
|
gz.Reset(w)
|
||||||
|
defer gz.Close()
|
||||||
|
|
||||||
|
w = gz
|
||||||
|
}
|
||||||
|
|
||||||
|
enc := expfmt.NewEncoder(w, contentType)
|
||||||
|
|
||||||
var lastErr error
|
var lastErr error
|
||||||
for _, mf := range mfs {
|
for _, mf := range mfs {
|
||||||
if err := enc.Encode(mf); err != nil {
|
if err := enc.Encode(mf); err != nil {
|
||||||
lastErr = err
|
lastErr = err
|
||||||
if opts.ErrorLog != nil {
|
if opts.ErrorLog != nil {
|
||||||
opts.ErrorLog.Println("error encoding metric family:", err)
|
opts.ErrorLog.Println("error encoding and sending metric family:", err)
|
||||||
}
|
}
|
||||||
switch opts.ErrorHandling {
|
switch opts.ErrorHandling {
|
||||||
case PanicOnError:
|
case PanicOnError:
|
||||||
|
@ -150,28 +153,15 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
|
||||||
case ContinueOnError:
|
case ContinueOnError:
|
||||||
// Handled later.
|
// Handled later.
|
||||||
case HTTPErrorOnError:
|
case HTTPErrorOnError:
|
||||||
http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
|
httpError(rsp, err)
|
||||||
return
|
return
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
if closer, ok := writer.(io.Closer); ok {
|
|
||||||
closer.Close()
|
if lastErr != nil {
|
||||||
|
httpError(rsp, lastErr)
|
||||||
}
|
}
|
||||||
if lastErr != nil && buf.Len() == 0 {
|
|
||||||
http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
|
|
||||||
return
|
|
||||||
}
|
|
||||||
header := w.Header()
|
|
||||||
header.Set(contentTypeHeader, string(contentType))
|
|
||||||
header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
|
|
||||||
if encoding != "" {
|
|
||||||
header.Set(contentEncodingHeader, encoding)
|
|
||||||
}
|
|
||||||
if _, err := w.Write(buf.Bytes()); err != nil && opts.ErrorLog != nil {
|
|
||||||
opts.ErrorLog.Println("error while sending encoded metrics:", err)
|
|
||||||
}
|
|
||||||
// TODO(beorn7): Consider streaming serving of metrics.
|
|
||||||
})
|
})
|
||||||
|
|
||||||
if opts.Timeout <= 0 {
|
if opts.Timeout <= 0 {
|
||||||
|
@ -292,20 +282,30 @@ type HandlerOpts struct {
|
||||||
Timeout time.Duration
|
Timeout time.Duration
|
||||||
}
|
}
|
||||||
|
|
||||||
// decorateWriter wraps a writer to handle gzip compression if requested. It
|
// gzipAccepted returns whether the client will accept gzip-encoded content.
|
||||||
// returns the decorated writer and the appropriate "Content-Encoding" header
|
func gzipAccepted(header http.Header) bool {
|
||||||
// (which is empty if no compression is enabled).
|
a := header.Get(acceptEncodingHeader)
|
||||||
func decorateWriter(request *http.Request, writer io.Writer, compressionDisabled bool) (io.Writer, string) {
|
parts := strings.Split(a, ",")
|
||||||
if compressionDisabled {
|
|
||||||
return writer, ""
|
|
||||||
}
|
|
||||||
header := request.Header.Get(acceptEncodingHeader)
|
|
||||||
parts := strings.Split(header, ",")
|
|
||||||
for _, part := range parts {
|
for _, part := range parts {
|
||||||
part = strings.TrimSpace(part)
|
part = strings.TrimSpace(part)
|
||||||
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
|
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
|
||||||
return gzip.NewWriter(writer), "gzip"
|
return true
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
return writer, ""
|
return false
|
||||||
|
}
|
||||||
|
|
||||||
|
// httpError removes any content-encoding header and then calls http.Error with
|
||||||
|
// the provided error and http.StatusInternalServerErrer. Error contents is
|
||||||
|
// supposed to be uncompressed plain text. However, same as with a plain
|
||||||
|
// http.Error, any header settings will be void if the header has already been
|
||||||
|
// sent. The error message will still be written to the writer, but it will
|
||||||
|
// probably be of limited use.
|
||||||
|
func httpError(rsp http.ResponseWriter, err error) {
|
||||||
|
rsp.Header().Del(contentEncodingHeader)
|
||||||
|
http.Error(
|
||||||
|
rsp,
|
||||||
|
"An error has occurred while serving metrics:\n\n"+err.Error(),
|
||||||
|
http.StatusInternalServerError,
|
||||||
|
)
|
||||||
}
|
}
|
||||||
|
|
|
@ -103,7 +103,7 @@ func TestHandlerErrorHandling(t *testing.T) {
|
||||||
})
|
})
|
||||||
wantMsg := `error gathering metrics: error collecting metric Desc{fqName: "invalid_metric", help: "not helpful", constLabels: {}, variableLabels: []}: collect error
|
wantMsg := `error gathering metrics: error collecting metric Desc{fqName: "invalid_metric", help: "not helpful", constLabels: {}, variableLabels: []}: collect error
|
||||||
`
|
`
|
||||||
wantErrorBody := `An error has occurred during metrics gathering:
|
wantErrorBody := `An error has occurred while serving metrics:
|
||||||
|
|
||||||
error collecting metric Desc{fqName: "invalid_metric", help: "not helpful", constLabels: {}, variableLabels: []}: collect error
|
error collecting metric Desc{fqName: "invalid_metric", help: "not helpful", constLabels: {}, variableLabels: []}: collect error
|
||||||
`
|
`
|
||||||
|
|
|
@ -250,7 +250,7 @@ metric: <
|
||||||
},
|
},
|
||||||
}
|
}
|
||||||
|
|
||||||
expectedMetricFamilyInvalidLabelValueAsText := []byte(`An error has occurred during metrics gathering:
|
expectedMetricFamilyInvalidLabelValueAsText := []byte(`An error has occurred while serving metrics:
|
||||||
|
|
||||||
collected metric "name" { label:<name:"constname" value:"\377" > label:<name:"labelname" value:"different_val" > counter:<value:42 > } has a label named "constname" whose value is not utf8: "\xff"
|
collected metric "name" { label:<name:"constname" value:"\377" > label:<name:"labelname" value:"different_val" > counter:<value:42 > } has a label named "constname" whose value is not utf8: "\xff"
|
||||||
`)
|
`)
|
||||||
|
@ -299,15 +299,15 @@ complex_bucket 1
|
||||||
},
|
},
|
||||||
},
|
},
|
||||||
}
|
}
|
||||||
bucketCollisionMsg := []byte(`An error has occurred during metrics gathering:
|
bucketCollisionMsg := []byte(`An error has occurred while serving metrics:
|
||||||
|
|
||||||
collected metric named "complex_bucket" collides with previously collected histogram named "complex"
|
collected metric named "complex_bucket" collides with previously collected histogram named "complex"
|
||||||
`)
|
`)
|
||||||
summaryCountCollisionMsg := []byte(`An error has occurred during metrics gathering:
|
summaryCountCollisionMsg := []byte(`An error has occurred while serving metrics:
|
||||||
|
|
||||||
collected metric named "complex_count" collides with previously collected summary named "complex"
|
collected metric named "complex_count" collides with previously collected summary named "complex"
|
||||||
`)
|
`)
|
||||||
histogramCountCollisionMsg := []byte(`An error has occurred during metrics gathering:
|
histogramCountCollisionMsg := []byte(`An error has occurred while serving metrics:
|
||||||
|
|
||||||
collected metric named "complex_count" collides with previously collected histogram named "complex"
|
collected metric named "complex_count" collides with previously collected histogram named "complex"
|
||||||
`)
|
`)
|
||||||
|
@ -333,7 +333,7 @@ collected metric named "complex_count" collides with previously collected histog
|
||||||
},
|
},
|
||||||
},
|
},
|
||||||
}
|
}
|
||||||
duplicateLabelMsg := []byte(`An error has occurred during metrics gathering:
|
duplicateLabelMsg := []byte(`An error has occurred while serving metrics:
|
||||||
|
|
||||||
collected metric "broken_metric" { label:<name:"foo" value:"bar" > label:<name:"foo" value:"baz" > counter:<value:2.7 > } has two or more labels with the same name: foo
|
collected metric "broken_metric" { label:<name:"foo" value:"bar" > label:<name:"foo" value:"baz" > counter:<value:2.7 > } has two or more labels with the same name: foo
|
||||||
`)
|
`)
|
||||||
|
|
Loading…
Reference in New Issue