HTTPSamplingStrategyFetcher: Use http client with 10 second timeout (j…

…aegertracing#578) * Use http client with 10 second timeout Signed-off-by: Joe Elliott <[email protected]> * lint Signed-off-by: Joe Elliott <[email protected]>
tttoad · Apr 28, 2021 · 7a33f7c · 7a33f7c
1 parent ba87d35
commit 7a33f7c
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Showing 2 changed files with 19 additions and 8 deletions.
diff --git a/sampler_remote.go b/sampler_remote.go
@@ -29,6 +29,7 @@ import (
 )
 
 const (
+	defaultRemoteSamplingTimeout   = 10 * time.Second
 	defaultSamplingRefreshInterval = time.Minute
 )
 
@@ -298,17 +299,30 @@ func (u *AdaptiveSamplerUpdater) Update(sampler SamplerV2, strategy interface{})
 // -----------------------
 
 type httpSamplingStrategyFetcher struct {
-	serverURL string
-	logger    log.DebugLogger
+	serverURL  string
+	logger     log.DebugLogger
+	httpClient http.Client
+}
+
+func newHTTPSamplingStrategyFetcher(serverURL string, logger log.DebugLogger) *httpSamplingStrategyFetcher {
+	customTransport := http.DefaultTransport.(*http.Transport).Clone()
+	customTransport.ResponseHeaderTimeout = defaultRemoteSamplingTimeout
+
+	return &httpSamplingStrategyFetcher{
+		serverURL: serverURL,
+		logger:    logger,
+		httpClient: http.Client{
+			Transport: customTransport,
+		},
+	}
 }
 
 func (f *httpSamplingStrategyFetcher) Fetch(serviceName string) ([]byte, error) {
 	v := url.Values{}
 	v.Set("service", serviceName)
 	uri := f.serverURL + "?" + v.Encode()
 
-	// TODO create and reuse http.Client with proper timeout settings, etc.
-	resp, err := http.Get(uri)
+	resp, err := f.httpClient.Get(uri)
 	if err != nil {
 		return nil, err
 	}

diff --git a/sampler_remote_options.go b/sampler_remote_options.go
@@ -140,10 +140,7 @@ func (o *samplerOptions) applyOptionsAndDefaults(opts ...SamplerOption) *sampler
 		o.samplingRefreshInterval = defaultSamplingRefreshInterval
 	}
 	if o.samplingFetcher == nil {
-		o.samplingFetcher = &httpSamplingStrategyFetcher{
-			serverURL: o.samplingServerURL,
-			logger:    o.logger,
-		}
+		o.samplingFetcher = newHTTPSamplingStrategyFetcher(o.samplingServerURL, o.logger)
 	}
 	if o.samplingParser == nil {
 		o.samplingParser = new(samplingStrategyParser)