Update default samplingServerURL to include /sampling path

README.md

@@ -68,7 +68,7 @@ NOTE: It is not recommended to use a remote host for UDP connections.
 
 ### Updating Sampling Server URL
 
-The default sampling collector URL is `http://127.0.0.1:5778`. Similar to UDP address above, you can use a different URL by updating the sampler configuration.
+The default sampling collector URL is `http://127.0.0.1:5778/sampling`. Similar to UDP address above, you can use a different URL by updating the sampler configuration.
 
 ```yml
 sampler:

src/jaegertracing/ConfigTest.cpp

@@ -73,6 +73,12 @@ TEST(Config, testDefaultSamplingProbability)
               Config().sampler().param());
 }
 
+TEST(Config, testDefaultSamplingServerURL)
+{
+    ASSERT_EQ("http://127.0.0.1:5778/sampling",
+              Config().sampler().samplingServerURL());
+}
+
 TEST(Config, testZeroSamplingParam)
 {
     {

src/jaegertracing/samplers/Config.h

@@ -42,7 +42,7 @@ class Config {
 
     static constexpr auto kDefaultSamplingProbability =
         static_cast<double>(0.001);
-    static constexpr auto kDefaultSamplingServerURL = "http://127.0.0.1:5778";
+    static constexpr auto kDefaultSamplingServerURL = "http://127.0.0.1:5778/sampling";
     static constexpr auto kDefaultMaxOperations = 2000;
 
     static Clock::duration defaultSamplingRefreshInterval()