From 52eaacc929648f6a1b0b0153594625663b215974 Mon Sep 17 00:00:00 2001
From: Andrew Kent <andrew.kent@datadoghq.com>
Date: Wed, 12 Dec 2018 13:39:32 -0800
Subject: [PATCH] Enable priority sampling by default

---
 .../src/main/java/datadog/trace/api/Config.java     |  2 +-
 .../test/groovy/datadog/trace/api/ConfigTest.groovy | 10 +++++-----
 .../test/groovy/datadog/trace/DDTracerTest.groovy   | 13 ++++++-------
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/dd-trace-api/src/main/java/datadog/trace/api/Config.java b/dd-trace-api/src/main/java/datadog/trace/api/Config.java
index f68e071f62..8d80b7b51b 100644
--- a/dd-trace-api/src/main/java/datadog/trace/api/Config.java
+++ b/dd-trace-api/src/main/java/datadog/trace/api/Config.java
@@ -61,7 +61,7 @@ public class Config {
 
   private static final boolean DEFAULT_RUNTIME_CONTEXT_FIELD_INJECTION = true;
 
-  private static final boolean DEFAULT_PRIORITY_SAMPLING_ENABLED = false;
+  private static final boolean DEFAULT_PRIORITY_SAMPLING_ENABLED = true;
   private static final boolean DEFAULT_TRACE_RESOLVER_ENABLED = true;
   private static final boolean DEFAULT_JMX_FETCH_ENABLED = false;
 
diff --git a/dd-trace-api/src/test/groovy/datadog/trace/api/ConfigTest.groovy b/dd-trace-api/src/test/groovy/datadog/trace/api/ConfigTest.groovy
index 7f4e64c9b5..31a5a9eeac 100644
--- a/dd-trace-api/src/test/groovy/datadog/trace/api/ConfigTest.groovy
+++ b/dd-trace-api/src/test/groovy/datadog/trace/api/ConfigTest.groovy
@@ -31,7 +31,7 @@ class ConfigTest extends Specification {
     config.writerType == "DDAgentWriter"
     config.agentHost == "localhost"
     config.agentPort == 8126
-    config.prioritySamplingEnabled == false
+    config.prioritySamplingEnabled == true
     config.traceResolverEnabled == true
     config.serviceMapping == [:]
     config.mergedSpanTags == [:]
@@ -54,7 +54,7 @@ class ConfigTest extends Specification {
     System.setProperty(PREFIX + AGENT_HOST, "somehost")
     System.setProperty(PREFIX + TRACE_AGENT_PORT, "123")
     System.setProperty(PREFIX + AGENT_PORT_LEGACY, "456")
-    System.setProperty(PREFIX + PRIORITY_SAMPLING, "true")
+    System.setProperty(PREFIX + PRIORITY_SAMPLING, "false")
     System.setProperty(PREFIX + TRACE_RESOLVER_ENABLED, "false")
     System.setProperty(PREFIX + SERVICE_MAPPING, "a:1")
     System.setProperty(PREFIX + GLOBAL_TAGS, "b:2")
@@ -77,7 +77,7 @@ class ConfigTest extends Specification {
     config.writerType == "LoggingWriter"
     config.agentHost == "somehost"
     config.agentPort == 123
-    config.prioritySamplingEnabled == true
+    config.prioritySamplingEnabled == false
     config.traceResolverEnabled == false
     config.serviceMapping == [a: "1"]
     config.mergedSpanTags == [b: "2", c: "3"]
@@ -177,7 +177,7 @@ class ConfigTest extends Specification {
     properties.setProperty(WRITER_TYPE, "LoggingWriter")
     properties.setProperty(AGENT_HOST, "somehost")
     properties.setProperty(TRACE_AGENT_PORT, "123")
-    properties.setProperty(PRIORITY_SAMPLING, "true")
+    properties.setProperty(PRIORITY_SAMPLING, "false")
     properties.setProperty(TRACE_RESOLVER_ENABLED, "false")
     properties.setProperty(SERVICE_MAPPING, "a:1")
     properties.setProperty(GLOBAL_TAGS, "b:2")
@@ -198,7 +198,7 @@ class ConfigTest extends Specification {
     config.writerType == "LoggingWriter"
     config.agentHost == "somehost"
     config.agentPort == 123
-    config.prioritySamplingEnabled == true
+    config.prioritySamplingEnabled == false
     config.traceResolverEnabled == false
     config.serviceMapping == [a: "1"]
     config.mergedSpanTags == [b: "2", c: "3"]
diff --git a/dd-trace-ot/src/test/groovy/datadog/trace/DDTracerTest.groovy b/dd-trace-ot/src/test/groovy/datadog/trace/DDTracerTest.groovy
index c6c839f707..40b6574111 100644
--- a/dd-trace-ot/src/test/groovy/datadog/trace/DDTracerTest.groovy
+++ b/dd-trace-ot/src/test/groovy/datadog/trace/DDTracerTest.groovy
@@ -42,21 +42,20 @@ class DDTracerTest extends Specification {
 
     then:
     tracer.serviceName == "unnamed-java-app"
-    tracer.sampler instanceof AllSampler
+    tracer.sampler instanceof RateByServiceSampler
     tracer.writer.toString() == "DDAgentWriter { api=DDApi { tracesEndpoint=http://localhost:8126/v0.3/traces } }"
 
     tracer.spanContextDecorators.size() == 12
   }
 
+
   def "verify overriding sampler"() {
     setup:
-    System.setProperty(PREFIX + PRIORITY_SAMPLING, "true")
-
+    System.setProperty(PREFIX + PRIORITY_SAMPLING, "false")
     when:
     def tracer = new DDTracer(new Config())
-
     then:
-    tracer.sampler instanceof RateByServiceSampler
+    tracer.sampler instanceof AllSampler
   }
 
   def "verify overriding writer"() {
@@ -136,7 +135,7 @@ class DDTracerTest extends Specification {
 
     where:
     key                      | value
-    Config.PRIORITY_SAMPLING | "true"
-    Config.PRIORITY_SAMPLING | "false"
+    PRIORITY_SAMPLING | "true"
+    PRIORITY_SAMPLING | "false"
   }
 }