restic/vendor/cloud.google.com/go/trace/trace_test.go

970 lines
28 KiB
Go

// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package trace
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"math/rand"
"net/http"
"regexp"
"strings"
"sync"
"testing"
"time"
"cloud.google.com/go/datastore"
"cloud.google.com/go/internal/testutil"
"cloud.google.com/go/storage"
"golang.org/x/net/context"
api "google.golang.org/api/cloudtrace/v1"
compute "google.golang.org/api/compute/v1"
"google.golang.org/api/iterator"
"google.golang.org/api/option"
dspb "google.golang.org/genproto/googleapis/datastore/v1"
"google.golang.org/grpc"
)
const testProjectID = "testproject"
type fakeRoundTripper struct {
reqc chan *http.Request
}
func newFakeRoundTripper() *fakeRoundTripper {
return &fakeRoundTripper{reqc: make(chan *http.Request)}
}
func (rt *fakeRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) {
rt.reqc <- r
resp := &http.Response{
Status: "200 OK",
StatusCode: 200,
Body: ioutil.NopCloser(strings.NewReader("{}")),
}
return resp, nil
}
func newTestClient(rt http.RoundTripper) *Client {
t, err := NewClient(context.Background(), testProjectID, option.WithHTTPClient(&http.Client{Transport: rt}))
if err != nil {
panic(err)
}
return t
}
type fakeDatastoreServer struct {
dspb.DatastoreServer
fail bool
}
func (f *fakeDatastoreServer) Lookup(ctx context.Context, req *dspb.LookupRequest) (*dspb.LookupResponse, error) {
if f.fail {
return nil, errors.New("lookup failed")
}
return &dspb.LookupResponse{}, nil
}
// makeRequests makes some requests.
// span is the root span. rt is the trace client's http client's transport.
// This is used to retrieve the trace uploaded by the client, if any. If
// expectTrace is true, we expect a trace will be uploaded. If synchronous is
// true, the call to Finish is expected not to return before the client has
// uploaded any traces.
func makeRequests(t *testing.T, span *Span, rt *fakeRoundTripper, synchronous bool, expectTrace bool) *http.Request {
ctx := NewContext(context.Background(), span)
tc := newTestClient(&noopTransport{})
// An HTTP request.
{
req2, err := http.NewRequest("GET", "http://example.com/bar", nil)
if err != nil {
t.Fatal(err)
}
resp := &http.Response{StatusCode: 200}
s := span.NewRemoteChild(req2)
s.Finish(WithResponse(resp))
}
// An autogenerated API call.
{
rt := &fakeRoundTripper{reqc: make(chan *http.Request, 1)}
hc := &http.Client{Transport: rt}
computeClient, err := compute.New(hc)
if err != nil {
t.Fatal(err)
}
_, err = computeClient.Zones.List(testProjectID).Context(ctx).Do()
if err != nil {
t.Fatal(err)
}
}
// A cloud library call that uses the autogenerated API.
{
rt := &fakeRoundTripper{reqc: make(chan *http.Request, 1)}
hc := &http.Client{Transport: rt}
storageClient, err := storage.NewClient(context.Background(), option.WithHTTPClient(hc))
if err != nil {
t.Fatal(err)
}
var objAttrsList []*storage.ObjectAttrs
it := storageClient.Bucket("testbucket").Objects(ctx, nil)
for {
objAttrs, err := it.Next()
if err != nil && err != iterator.Done {
t.Fatal(err)
}
if err == iterator.Done {
break
}
objAttrsList = append(objAttrsList, objAttrs)
}
}
// A cloud library call that uses grpc internally.
for _, fail := range []bool{false, true} {
srv, err := testutil.NewServer()
if err != nil {
t.Fatalf("creating test datastore server: %v", err)
}
dspb.RegisterDatastoreServer(srv.Gsrv, &fakeDatastoreServer{fail: fail})
srv.Start()
conn, err := grpc.Dial(srv.Addr, grpc.WithInsecure(), grpc.WithUnaryInterceptor(tc.GRPCClientInterceptor()))
if err != nil {
t.Fatalf("connecting to test datastore server: %v", err)
}
datastoreClient, err := datastore.NewClient(ctx, testProjectID, option.WithGRPCConn(conn))
if err != nil {
t.Fatalf("creating datastore client: %v", err)
}
k := datastore.NameKey("Entity", "stringID", nil)
e := new(datastore.Entity)
datastoreClient.Get(ctx, k, e)
}
done := make(chan struct{})
go func() {
if synchronous {
err := span.FinishWait()
if err != nil {
t.Errorf("Unexpected error from span.FinishWait: %v", err)
}
} else {
span.Finish()
}
done <- struct{}{}
}()
if !expectTrace {
<-done
select {
case <-rt.reqc:
t.Errorf("Got a trace, expected none.")
case <-time.After(5 * time.Millisecond):
}
return nil
} else if !synchronous {
<-done
return <-rt.reqc
} else {
select {
case <-done:
t.Errorf("Synchronous Finish didn't wait for trace upload.")
return <-rt.reqc
case <-time.After(5 * time.Millisecond):
r := <-rt.reqc
<-done
return r
}
}
}
func TestHeader(t *testing.T) {
tests := []struct {
header string
wantTraceID string
wantSpanID uint64
wantOpts optionFlags
wantOK bool
}{
{
header: "0123456789ABCDEF0123456789ABCDEF/1;o=1",
wantTraceID: "0123456789ABCDEF0123456789ABCDEF",
wantSpanID: 1,
wantOpts: 1,
wantOK: true,
},
{
header: "0123456789ABCDEF0123456789ABCDEF/1;o=0",
wantTraceID: "0123456789ABCDEF0123456789ABCDEF",
wantSpanID: 1,
wantOpts: 0,
wantOK: true,
},
{
header: "0123456789ABCDEF0123456789ABCDEF/1",
wantTraceID: "0123456789ABCDEF0123456789ABCDEF",
wantSpanID: 1,
wantOpts: 0,
wantOK: true,
},
{
header: "",
wantTraceID: "",
wantSpanID: 0,
wantOpts: 0,
wantOK: false,
},
}
for _, tt := range tests {
traceID, parentSpanID, opts, _, ok := traceInfoFromHeader(tt.header)
if got, want := traceID, tt.wantTraceID; got != want {
t.Errorf("TraceID(%v) = %q; want %q", tt.header, got, want)
}
if got, want := parentSpanID, tt.wantSpanID; got != want {
t.Errorf("SpanID(%v) = %v; want %v", tt.header, got, want)
}
if got, want := opts, tt.wantOpts; got != want {
t.Errorf("Options(%v) = %v; want %v", tt.header, got, want)
}
if got, want := ok, tt.wantOK; got != want {
t.Errorf("Header exists (%v) = %v; want %v", tt.header, got, want)
}
}
}
func TestOutgoingReqHeader(t *testing.T) {
all, _ := NewLimitedSampler(1, 1<<16) // trace every request
tests := []struct {
desc string
traceHeader string
samplingPolicy SamplingPolicy
wantHeaderRe *regexp.Regexp
}{
{
desc: "Parent span without sampling options, client samples all",
traceHeader: "0123456789ABCDEF0123456789ABCDEF/1",
samplingPolicy: all,
wantHeaderRe: regexp.MustCompile("0123456789ABCDEF0123456789ABCDEF/\\d+;o=1"),
},
{
desc: "Parent span without sampling options, without client sampling",
traceHeader: "0123456789ABCDEF0123456789ABCDEF/1",
samplingPolicy: nil,
wantHeaderRe: regexp.MustCompile("0123456789ABCDEF0123456789ABCDEF/\\d+;o=0"),
},
{
desc: "Parent span with o=1, client samples none",
traceHeader: "0123456789ABCDEF0123456789ABCDEF/1;o=1",
samplingPolicy: nil,
wantHeaderRe: regexp.MustCompile("0123456789ABCDEF0123456789ABCDEF/\\d+;o=1"),
},
{
desc: "Parent span with o=0, without client sampling",
traceHeader: "0123456789ABCDEF0123456789ABCDEF/1;o=0",
samplingPolicy: nil,
wantHeaderRe: regexp.MustCompile("0123456789ABCDEF0123456789ABCDEF/\\d+;o=0"),
},
}
tc := newTestClient(nil)
for _, tt := range tests {
tc.SetSamplingPolicy(tt.samplingPolicy)
span := tc.SpanFromHeader("/foo", tt.traceHeader)
req, _ := http.NewRequest("GET", "http://localhost", nil)
span.NewRemoteChild(req)
if got, re := req.Header.Get(httpHeader), tt.wantHeaderRe; !re.MatchString(got) {
t.Errorf("%v (parent=%q): got header %q; want in format %q", tt.desc, tt.traceHeader, got, re)
}
}
}
func TestTrace(t *testing.T) {
t.Parallel()
testTrace(t, false, true)
}
func TestTraceWithWait(t *testing.T) {
testTrace(t, true, true)
}
func TestTraceFromHeader(t *testing.T) {
t.Parallel()
testTrace(t, false, false)
}
func TestTraceFromHeaderWithWait(t *testing.T) {
testTrace(t, false, true)
}
func TestNewSpan(t *testing.T) {
t.Skip("flaky")
const traceID = "0123456789ABCDEF0123456789ABCDEF"
rt := newFakeRoundTripper()
traceClient := newTestClient(rt)
span := traceClient.NewSpan("/foo")
span.trace.traceID = traceID
uploaded := makeRequests(t, span, rt, true, true)
if uploaded == nil {
t.Fatalf("No trace uploaded, expected one.")
}
expected := api.Traces{
Traces: []*api.Trace{
{
ProjectId: testProjectID,
Spans: []*api.TraceSpan{
{
Kind: "RPC_CLIENT",
Labels: map[string]string{
"trace.cloud.google.com/http/host": "example.com",
"trace.cloud.google.com/http/method": "GET",
"trace.cloud.google.com/http/status_code": "200",
"trace.cloud.google.com/http/url": "http://example.com/bar",
},
Name: "example.com/bar",
},
{
Kind: "RPC_CLIENT",
Labels: map[string]string{
"trace.cloud.google.com/http/host": "www.googleapis.com",
"trace.cloud.google.com/http/method": "GET",
"trace.cloud.google.com/http/status_code": "200",
"trace.cloud.google.com/http/url": "https://www.googleapis.com/compute/v1/projects/testproject/zones",
},
Name: "www.googleapis.com/compute/v1/projects/testproject/zones",
},
{
Kind: "RPC_CLIENT",
Labels: map[string]string{
"trace.cloud.google.com/http/host": "www.googleapis.com",
"trace.cloud.google.com/http/method": "GET",
"trace.cloud.google.com/http/status_code": "200",
"trace.cloud.google.com/http/url": "https://www.googleapis.com/storage/v1/b/testbucket/o",
},
Name: "www.googleapis.com/storage/v1/b/testbucket/o",
},
&api.TraceSpan{
Kind: "RPC_CLIENT",
Labels: nil,
Name: "/google.datastore.v1.Datastore/Lookup",
},
&api.TraceSpan{
Kind: "RPC_CLIENT",
Labels: map[string]string{"error": "rpc error: code = Unknown desc = lookup failed"},
Name: "/google.datastore.v1.Datastore/Lookup",
},
{
Kind: "SPAN_KIND_UNSPECIFIED",
Labels: map[string]string{},
Name: "/foo",
},
},
TraceId: traceID,
},
},
}
body, err := ioutil.ReadAll(uploaded.Body)
if err != nil {
t.Fatal(err)
}
var patch api.Traces
err = json.Unmarshal(body, &patch)
if err != nil {
t.Fatal(err)
}
checkTraces(t, patch, expected)
n := len(patch.Traces[0].Spans)
rootSpan := patch.Traces[0].Spans[n-1]
for i, s := range patch.Traces[0].Spans {
if a, b := s.StartTime, s.EndTime; a > b {
t.Errorf("span %d start time is later than its end time (%q, %q)", i, a, b)
}
if a, b := rootSpan.StartTime, s.StartTime; a > b {
t.Errorf("trace start time is later than span %d start time (%q, %q)", i, a, b)
}
if a, b := s.EndTime, rootSpan.EndTime; a > b {
t.Errorf("span %d end time is later than trace end time (%q, %q)", i, a, b)
}
if i > 1 && i < n-1 {
if a, b := patch.Traces[0].Spans[i-1].EndTime, s.StartTime; a > b {
t.Errorf("span %d end time is later than span %d start time (%q, %q)", i-1, i, a, b)
}
}
}
if x := rootSpan.ParentSpanId; x != 0 {
t.Errorf("Incorrect ParentSpanId: got %d want %d", x, 0)
}
for i, s := range patch.Traces[0].Spans {
if x, y := rootSpan.SpanId, s.ParentSpanId; i < n-1 && x != y {
t.Errorf("Incorrect ParentSpanId in span %d: got %d want %d", i, y, x)
}
}
for i, s := range patch.Traces[0].Spans {
s.EndTime = ""
labels := &expected.Traces[0].Spans[i].Labels
for key, value := range *labels {
if v, ok := s.Labels[key]; !ok {
t.Errorf("Span %d is missing Label %q:%q", i, key, value)
} else if key == "trace.cloud.google.com/http/url" {
if !strings.HasPrefix(v, value) {
t.Errorf("Span %d Label %q: got value %q want prefix %q", i, key, v, value)
}
} else if v != value {
t.Errorf("Span %d Label %q: got value %q want %q", i, key, v, value)
}
}
for key := range s.Labels {
if _, ok := (*labels)[key]; key != "trace.cloud.google.com/stacktrace" && !ok {
t.Errorf("Span %d: unexpected label %q", i, key)
}
}
*labels = nil
s.Labels = nil
s.ParentSpanId = 0
if s.SpanId == 0 {
t.Errorf("Incorrect SpanId: got 0 want nonzero")
}
s.SpanId = 0
s.StartTime = ""
}
if !testutil.Equal(patch, expected) {
got, _ := json.Marshal(patch)
want, _ := json.Marshal(expected)
t.Errorf("PatchTraces request: got %s want %s", got, want)
}
}
func testTrace(t *testing.T, synchronous bool, fromRequest bool) {
t.Skip("flaky")
const header = `0123456789ABCDEF0123456789ABCDEF/42;o=3`
rt := newFakeRoundTripper()
traceClient := newTestClient(rt)
span := traceClient.SpanFromHeader("/foo", header)
headerOrReqLabels := map[string]string{}
headerOrReqName := "/foo"
if fromRequest {
req, err := http.NewRequest("GET", "http://example.com/foo", nil)
if err != nil {
t.Fatal(err)
}
req.Header.Set("X-Cloud-Trace-Context", header)
span = traceClient.SpanFromRequest(req)
headerOrReqLabels = map[string]string{
"trace.cloud.google.com/http/host": "example.com",
"trace.cloud.google.com/http/method": "GET",
"trace.cloud.google.com/http/url": "http://example.com/foo",
}
headerOrReqName = "example.com/foo"
}
uploaded := makeRequests(t, span, rt, synchronous, true)
if uploaded == nil {
t.Fatalf("No trace uploaded, expected one.")
}
expected := api.Traces{
Traces: []*api.Trace{
{
ProjectId: testProjectID,
Spans: []*api.TraceSpan{
{
Kind: "RPC_CLIENT",
Labels: map[string]string{
"trace.cloud.google.com/http/host": "example.com",
"trace.cloud.google.com/http/method": "GET",
"trace.cloud.google.com/http/status_code": "200",
"trace.cloud.google.com/http/url": "http://example.com/bar",
},
Name: "example.com/bar",
},
{
Kind: "RPC_CLIENT",
Labels: map[string]string{
"trace.cloud.google.com/http/host": "www.googleapis.com",
"trace.cloud.google.com/http/method": "GET",
"trace.cloud.google.com/http/status_code": "200",
"trace.cloud.google.com/http/url": "https://www.googleapis.com/compute/v1/projects/testproject/zones",
},
Name: "www.googleapis.com/compute/v1/projects/testproject/zones",
},
{
Kind: "RPC_CLIENT",
Labels: map[string]string{
"trace.cloud.google.com/http/host": "www.googleapis.com",
"trace.cloud.google.com/http/method": "GET",
"trace.cloud.google.com/http/status_code": "200",
"trace.cloud.google.com/http/url": "https://www.googleapis.com/storage/v1/b/testbucket/o",
},
Name: "www.googleapis.com/storage/v1/b/testbucket/o",
},
&api.TraceSpan{
Kind: "RPC_CLIENT",
Labels: nil,
Name: "/google.datastore.v1.Datastore/Lookup",
},
&api.TraceSpan{
Kind: "RPC_CLIENT",
Labels: map[string]string{"error": "rpc error: code = Unknown desc = lookup failed"},
Name: "/google.datastore.v1.Datastore/Lookup",
},
{
Kind: "RPC_SERVER",
Labels: headerOrReqLabels,
Name: headerOrReqName,
},
},
TraceId: "0123456789ABCDEF0123456789ABCDEF",
},
},
}
body, err := ioutil.ReadAll(uploaded.Body)
if err != nil {
t.Fatal(err)
}
var patch api.Traces
err = json.Unmarshal(body, &patch)
if err != nil {
t.Fatal(err)
}
checkTraces(t, patch, expected)
n := len(patch.Traces[0].Spans)
rootSpan := patch.Traces[0].Spans[n-1]
for i, s := range patch.Traces[0].Spans {
if a, b := s.StartTime, s.EndTime; a > b {
t.Errorf("span %d start time is later than its end time (%q, %q)", i, a, b)
}
if a, b := rootSpan.StartTime, s.StartTime; a > b {
t.Errorf("trace start time is later than span %d start time (%q, %q)", i, a, b)
}
if a, b := s.EndTime, rootSpan.EndTime; a > b {
t.Errorf("span %d end time is later than trace end time (%q, %q)", i, a, b)
}
if i > 1 && i < n-1 {
if a, b := patch.Traces[0].Spans[i-1].EndTime, s.StartTime; a > b {
t.Errorf("span %d end time is later than span %d start time (%q, %q)", i-1, i, a, b)
}
}
}
if x := rootSpan.ParentSpanId; x != 42 {
t.Errorf("Incorrect ParentSpanId: got %d want %d", x, 42)
}
for i, s := range patch.Traces[0].Spans {
if x, y := rootSpan.SpanId, s.ParentSpanId; i < n-1 && x != y {
t.Errorf("Incorrect ParentSpanId in span %d: got %d want %d", i, y, x)
}
}
for i, s := range patch.Traces[0].Spans {
s.EndTime = ""
labels := &expected.Traces[0].Spans[i].Labels
for key, value := range *labels {
if v, ok := s.Labels[key]; !ok {
t.Errorf("Span %d is missing Label %q:%q", i, key, value)
} else if key == "trace.cloud.google.com/http/url" {
if !strings.HasPrefix(v, value) {
t.Errorf("Span %d Label %q: got value %q want prefix %q", i, key, v, value)
}
} else if v != value {
t.Errorf("Span %d Label %q: got value %q want %q", i, key, v, value)
}
}
for key := range s.Labels {
if _, ok := (*labels)[key]; key != "trace.cloud.google.com/stacktrace" && !ok {
t.Errorf("Span %d: unexpected label %q", i, key)
}
}
*labels = nil
s.Labels = nil
s.ParentSpanId = 0
if s.SpanId == 0 {
t.Errorf("Incorrect SpanId: got 0 want nonzero")
}
s.SpanId = 0
s.StartTime = ""
}
if !testutil.Equal(patch, expected) {
got, _ := json.Marshal(patch)
want, _ := json.Marshal(expected)
t.Errorf("PatchTraces request: got %s \n\n want %s", got, want)
}
}
func TestNoTrace(t *testing.T) {
testNoTrace(t, false, true)
}
func TestNoTraceWithWait(t *testing.T) {
testNoTrace(t, true, true)
}
func TestNoTraceFromHeader(t *testing.T) {
testNoTrace(t, false, false)
}
func TestNoTraceFromHeaderWithWait(t *testing.T) {
testNoTrace(t, true, false)
}
func testNoTrace(t *testing.T, synchronous bool, fromRequest bool) {
for _, header := range []string{
`0123456789ABCDEF0123456789ABCDEF/42;o=2`,
`0123456789ABCDEF0123456789ABCDEF/42;o=0`,
`0123456789ABCDEF0123456789ABCDEF/42`,
`0123456789ABCDEF0123456789ABCDEF`,
``,
} {
rt := newFakeRoundTripper()
traceClient := newTestClient(rt)
var span *Span
if fromRequest {
req, err := http.NewRequest("GET", "http://example.com/foo", nil)
if header != "" {
req.Header.Set("X-Cloud-Trace-Context", header)
}
if err != nil {
t.Fatal(err)
}
span = traceClient.SpanFromRequest(req)
} else {
span = traceClient.SpanFromHeader("/foo", header)
}
uploaded := makeRequests(t, span, rt, synchronous, false)
if uploaded != nil {
t.Errorf("Got a trace, expected none.")
}
}
}
func TestSample(t *testing.T) {
// A deterministic test of the sampler logic.
type testCase struct {
rate float64
maxqps float64
want int
}
const delta = 25 * time.Millisecond
for _, test := range []testCase{
// qps won't matter, so we will sample half of the 79 calls
{0.50, 100, 40},
// with 1 qps and a burst of 2, we will sample twice in second #1, once in the partial second #2
{0.50, 1, 3},
} {
sp, err := NewLimitedSampler(test.rate, test.maxqps)
if err != nil {
t.Fatal(err)
}
s := sp.(*sampler)
sampled := 0
tm := time.Now()
for i := 0; i < 80; i++ {
if s.sample(Parameters{}, tm, float64(i%2)).Sample {
sampled++
}
tm = tm.Add(delta)
}
if sampled != test.want {
t.Errorf("rate=%f, maxqps=%f: got %d samples, want %d", test.rate, test.maxqps, sampled, test.want)
}
}
}
func TestSampling(t *testing.T) {
t.Parallel()
// This scope tests sampling in a larger context, with real time and randomness.
wg := sync.WaitGroup{}
type testCase struct {
rate float64
maxqps float64
expectedRange [2]int
}
for _, test := range []testCase{
{0, 5, [2]int{0, 0}},
{5, 0, [2]int{0, 0}},
{0.50, 100, [2]int{20, 60}},
{0.50, 1, [2]int{3, 4}}, // Windows, with its less precise clock, sometimes gives 4.
} {
wg.Add(1)
go func(test testCase) {
rt := newFakeRoundTripper()
traceClient := newTestClient(rt)
traceClient.bundler.BundleByteLimit = 1
p, err := NewLimitedSampler(test.rate, test.maxqps)
if err != nil {
t.Fatalf("NewLimitedSampler: %v", err)
}
traceClient.SetSamplingPolicy(p)
ticker := time.NewTicker(25 * time.Millisecond)
sampled := 0
for i := 0; i < 79; i++ {
req, err := http.NewRequest("GET", "http://example.com/foo", nil)
if err != nil {
t.Fatal(err)
}
span := traceClient.SpanFromRequest(req)
span.Finish()
select {
case <-rt.reqc:
<-ticker.C
sampled++
case <-ticker.C:
}
}
ticker.Stop()
if test.expectedRange[0] > sampled || sampled > test.expectedRange[1] {
t.Errorf("rate=%f, maxqps=%f: got %d samples want ∈ %v", test.rate, test.maxqps, sampled, test.expectedRange)
}
wg.Done()
}(test)
}
wg.Wait()
}
func TestBundling(t *testing.T) {
t.Parallel()
rt := newFakeRoundTripper()
traceClient := newTestClient(rt)
traceClient.bundler.DelayThreshold = time.Second / 2
traceClient.bundler.BundleCountThreshold = 10
p, err := NewLimitedSampler(1, 99) // sample every request.
if err != nil {
t.Fatalf("NewLimitedSampler: %v", err)
}
traceClient.SetSamplingPolicy(p)
for i := 0; i < 35; i++ {
go func() {
req, err := http.NewRequest("GET", "http://example.com/foo", nil)
if err != nil {
t.Fatal(err)
}
span := traceClient.SpanFromRequest(req)
span.Finish()
}()
}
// Read the first three bundles.
<-rt.reqc
<-rt.reqc
<-rt.reqc
// Test that the fourth bundle isn't sent early.
select {
case <-rt.reqc:
t.Errorf("bundle sent too early")
case <-time.After(time.Second / 4):
<-rt.reqc
}
// Test that there aren't extra bundles.
select {
case <-rt.reqc:
t.Errorf("too many bundles sent")
case <-time.After(time.Second):
}
}
func TestWeights(t *testing.T) {
const (
expectedNumTraced = 10100
numTracedEpsilon = 100
expectedTotalWeight = 50000
totalWeightEpsilon = 5000
)
rng := rand.New(rand.NewSource(1))
const delta = 2 * time.Millisecond
for _, headerRate := range []float64{0.0, 0.5, 1.0} {
// Simulate 10 seconds of requests arriving at 500qps.
//
// The sampling policy tries to sample 25% of them, but has a qps limit of
// 100, so it will not be able to. The returned weight should be higher
// for some sampled requests to compensate.
//
// headerRate is the fraction of incoming requests that have a trace header
// set. The qps limit should not be exceeded, even if headerRate is high.
sp, err := NewLimitedSampler(0.25, 100)
if err != nil {
t.Fatal(err)
}
s := sp.(*sampler)
tm := time.Now()
totalWeight := 0.0
numTraced := 0
seenLargeWeight := false
for i := 0; i < 50000; i++ {
d := s.sample(Parameters{HasTraceHeader: rng.Float64() < headerRate}, tm, rng.Float64())
if d.Trace {
numTraced++
}
if d.Sample {
totalWeight += d.Weight
if x := int(d.Weight) / 4; x <= 0 || x >= 100 || d.Weight != float64(x)*4.0 {
t.Errorf("weight: got %f, want a small positive multiple of 4", d.Weight)
}
if d.Weight > 4 {
seenLargeWeight = true
}
}
tm = tm.Add(delta)
}
if !seenLargeWeight {
t.Errorf("headerRate %f: never saw sample weight higher than 4.", headerRate)
}
if numTraced < expectedNumTraced-numTracedEpsilon || expectedNumTraced+numTracedEpsilon < numTraced {
t.Errorf("headerRate %f: got %d traced requests, want ∈ [%d, %d]", headerRate, numTraced, expectedNumTraced-numTracedEpsilon, expectedNumTraced+numTracedEpsilon)
}
if totalWeight < expectedTotalWeight-totalWeightEpsilon || expectedTotalWeight+totalWeightEpsilon < totalWeight {
t.Errorf("headerRate %f: got total weight %f want ∈ [%d, %d]", headerRate, totalWeight, expectedTotalWeight-totalWeightEpsilon, expectedTotalWeight+totalWeightEpsilon)
}
}
}
type alwaysTrace struct{}
func (a alwaysTrace) Sample(p Parameters) Decision {
return Decision{Trace: true}
}
type neverTrace struct{}
func (a neverTrace) Sample(p Parameters) Decision {
return Decision{Trace: false}
}
func TestPropagation(t *testing.T) {
rt := newFakeRoundTripper()
traceClient := newTestClient(rt)
for _, header := range []string{
`0123456789ABCDEF0123456789ABCDEF/42;o=0`,
`0123456789ABCDEF0123456789ABCDEF/42;o=1`,
`0123456789ABCDEF0123456789ABCDEF/42;o=2`,
`0123456789ABCDEF0123456789ABCDEF/42;o=3`,
`0123456789ABCDEF0123456789ABCDEF/0;o=0`,
`0123456789ABCDEF0123456789ABCDEF/0;o=1`,
`0123456789ABCDEF0123456789ABCDEF/0;o=2`,
`0123456789ABCDEF0123456789ABCDEF/0;o=3`,
``,
} {
for _, policy := range []SamplingPolicy{
nil,
alwaysTrace{},
neverTrace{},
} {
traceClient.SetSamplingPolicy(policy)
req, err := http.NewRequest("GET", "http://example.com/foo", nil)
if err != nil {
t.Fatal(err)
}
if header != "" {
req.Header.Set("X-Cloud-Trace-Context", header)
}
span := traceClient.SpanFromRequest(req)
req2, err := http.NewRequest("GET", "http://example.com/bar", nil)
if err != nil {
t.Fatal(err)
}
req3, err := http.NewRequest("GET", "http://example.com/baz", nil)
if err != nil {
t.Fatal(err)
}
span.NewRemoteChild(req2)
span.NewRemoteChild(req3)
var (
t1, t2, t3 string
s1, s2, s3 uint64
o1, o2, o3 uint64
)
fmt.Sscanf(header, "%32s/%d;o=%d", &t1, &s1, &o1)
fmt.Sscanf(req2.Header.Get("X-Cloud-Trace-Context"), "%32s/%d;o=%d", &t2, &s2, &o2)
fmt.Sscanf(req3.Header.Get("X-Cloud-Trace-Context"), "%32s/%d;o=%d", &t3, &s3, &o3)
if header == "" {
if t2 != t3 {
t.Errorf("expected the same trace ID in child requests, got %q %q", t2, t3)
}
} else {
if t2 != t1 || t3 != t1 {
t.Errorf("trace IDs should be passed to child requests")
}
}
trace := policy == alwaysTrace{} || policy == nil && (o1&1) != 0
if header == "" {
if trace && (s2 == 0 || s3 == 0) {
t.Errorf("got span IDs %d %d in child requests, want nonzero", s2, s3)
}
if trace && s2 == s3 {
t.Errorf("got span IDs %d %d in child requests, should be different", s2, s3)
}
if !trace && (s2 != 0 || s3 != 0) {
t.Errorf("got span IDs %d %d in child requests, want zero", s2, s3)
}
} else {
if trace && (s2 == s1 || s3 == s1 || s2 == s3) {
t.Errorf("parent span IDs in input and outputs should be all different, got %d %d %d", s1, s2, s3)
}
if !trace && (s2 != s1 || s3 != s1) {
t.Errorf("parent span ID in input, %d, should have been equal to parent span IDs in output: %d %d", s1, s2, s3)
}
}
expectTraceOption := policy == alwaysTrace{} || (o1&1) != 0
if expectTraceOption != ((o2&1) != 0) || expectTraceOption != ((o3&1) != 0) {
t.Errorf("tracing flag in child requests should be %t, got options %d %d", expectTraceOption, o2, o3)
}
}
}
}
func BenchmarkSpanFromHeader(b *testing.B) {
const header = `0123456789ABCDEF0123456789ABCDEF/42;o=0`
const name = "/foo"
rt := newFakeRoundTripper()
traceClient := newTestClient(rt)
for n := 0; n < b.N; n++ {
traceClient.SpanFromHeader(name, header)
}
}
func checkTraces(t *testing.T, patch, expected api.Traces) {
if len(patch.Traces) != len(expected.Traces) || len(patch.Traces[0].Spans) != len(expected.Traces[0].Spans) {
diff := testutil.Diff(patch.Traces, expected.Traces)
t.Logf("diff:\n%s", diff)
got, _ := json.Marshal(patch)
want, _ := json.Marshal(expected)
t.Fatalf("PatchTraces request: got %s want %s", got, want)
}
}