Deprecate CAT (#465)

* Deprecating TracedMethod.addOutboundRequestHeaders
* Disabling CAT by default

newrelic-agent/src/main/java/com/newrelic/agent/config/ConfigServiceImpl.java

@@ -97,6 +97,13 @@ protected void doStart() {
             getLogger().warning(msg);
         }
 
+        boolean isCrossApplicationTracing = localAgentConfig.getCrossProcessConfig().isCrossApplicationTracing();
+        if (isCrossApplicationTracing) {
+            String msg = "Distributed tracing is replacing cross application tracing as the default means of tracing between services. " +
+                    "To continue using cross application tracing, enable it with cross_application_tracer.enabled=true and distributed_tracing.enabled=false. ";
+            getLogger().info(msg);
+        }
+
         localAgentConfig.logDeprecatedProperties(fileSettings);
 
         ServiceFactory.getHarvestService().addHarvestListener(this);

newrelic-agent/src/main/java/com/newrelic/agent/config/CrossProcessConfigImpl.java

@@ -22,7 +22,7 @@ public final class CrossProcessConfigImpl extends BaseConfig implements CrossPro
     public static final String ENCODING_KEY = "encoding_key";
     public static final String TRUSTED_ACCOUNT_IDS = "trusted_account_ids";
     public static final String APPLICATION_ID = "application_id";
-    public static final boolean DEFAULT_ENABLED = true;
+    public static final boolean DEFAULT_ENABLED = false;
     public static final String SYSTEM_PROPERTY_ROOT = "newrelic.config.cross_application_tracer.";
 
     private final boolean isCrossApplicationTracing;

newrelic-agent/src/main/resources/newrelic.yml

@@ -251,11 +251,16 @@ common: &default_settings
   # Cross Application Tracing adds request and response headers to
   # external calls using supported HTTP libraries to provide better
   # performance data when calling applications monitored by other New Relic Agents.
+  #
+  # Distributed tracing is replacing cross application tracing as the default
+  # means of tracing between services. To continue using cross application
+  # tracing, enable it with `cross_application_tracer.enabled = true` and
+  # `distributed_tracing.enabled = false`
   cross_application_tracer:
 
-    # Set to false to disable cross application tracing.
-    # Default is true.
-    enabled: true
+    # Set to true to enable cross application tracing.
+    # Default is false.
+    enabled: false
 
   # Thread profiler measures wall clock time, CPU time, and method call counts
   # in your application's threads as they run.

newrelic-agent/src/test/java/com/newrelic/agent/CrossProcessAndSyntheticsConfigTest.java

@@ -120,7 +120,7 @@ private String makeYmlFilePath(String fileName) {
 
     @Test
     public void testConfig1() throws Exception {
-        testConfig(makeYmlFilePath("newrelic.yml"), true, true);
+        testConfig(makeYmlFilePath("newrelic.yml"), false, true);
     }
 
     @Test
@@ -140,7 +140,7 @@ public void testConfig4() throws Exception {
 
     @Test
     public void testConfig5() throws Exception {
-        testConfig(makeYmlFilePath("newrelicWithCrossAppTracingNotSpecified.yml"), true, true);
+        testConfig(makeYmlFilePath("newrelicWithCrossAppTracingNotSpecified.yml"), false, true);
     }
 
     // The "expected value" arguments are all about the newrelic.yml. We're not varying the collector JSON here.

newrelic-agent/src/test/java/com/newrelic/agent/config/AgentConfigFactoryTest.java

@@ -187,10 +187,16 @@ public void serverSideOverride() throws Exception {
     @Test
     public void crossProcess() throws Exception {
         Map<String, Object> localSettings = createMap();
+        Map<String, Object> catSettings = createMap();
         Map<String, Object> serverData = createMap();
+
+        // cat must be enabled for the other properties to be returned
+        catSettings.put(CrossProcessConfigImpl.ENABLED, true);
+        localSettings.put(AgentConfigImpl.CROSS_APPLICATION_TRACER, catSettings);
+
         List<String> trustedIds = new ArrayList<>();
         trustedIds.add("12345");
-        serverData.put(CrossProcessConfigImpl.CROSS_APPLICATION_TRACING, false); // deprecated setting
+        serverData.put(CrossProcessConfigImpl.CROSS_APPLICATION_TRACING, false); // deprecated setting is ignored when coming from the server
         serverData.put(CrossProcessConfigImpl.CROSS_PROCESS_ID, "1234#5678");
         serverData.put(CrossProcessConfigImpl.TRUSTED_ACCOUNT_IDS, trustedIds);
         serverData.put(CrossProcessConfigImpl.ENCODING_KEY, "test");

newrelic-agent/src/test/java/com/newrelic/agent/config/CrossProcessConfigImplTest.java

@@ -84,6 +84,10 @@ public void trustedIds() throws Exception {
     @Test
     public void encodingKey() throws Exception {
         Map<String, Object> serverSettings = new HashMap<>();
+
+        // CAT must be enabled, or the encoding key will be null
+        serverSettings.put(CrossProcessConfigImpl.ENABLED, true);
+
         String encodingKey = "test";
         ServerProp serverProp = ServerProp.createPropObject(encodingKey);
         serverSettings.put(CrossProcessConfigImpl.ENCODING_KEY, serverProp);

newrelic-agent/src/test/resources/com/newrelic/agent/config/newrelicWithBrowserMonitoringFalse.yml

@@ -16,6 +16,9 @@ common: &default_settings
 
   wait_for_rpm_connect: false
 
+  cross_application_tracer:
+    enabled: true
+
   # activemerchant instrumentation: only report dollar amounts (business data)
   # if the following is present and true; otherwise, only response times
   # and throughput to the gateway are reported

newrelic-agent/src/test/resources/com/newrelic/agent/config/newrelicWithBrowserMonitoringNotSpecified.yml

@@ -16,6 +16,9 @@ common: &default_settings
 
   wait_for_rpm_connect: false
 
+  cross_application_tracer:
+    enabled: true
+
   # activemerchant instrumentation: only report dollar amounts (business data)
   # if the following is present and true; otherwise, only response times
   # and throughput to the gateway are reported

newrelic-api/src/main/java/com/newrelic/api/agent/TracedMethod.java

@@ -69,7 +69,10 @@ public interface TracedMethod extends AttributeHolder {
      * @param outboundHeaders The headers that will be written to the output stream for the external request. This also
      *        determines if the external call is HTTP or JMS.
      * @since 3.36.0
+     * @deprecated Instead, use the Distributed Tracing API {@link Transaction#insertDistributedTraceHeaders(Headers)} to create a
+     * distributed tracing payload
      */
+    @Deprecated
     void addOutboundRequestHeaders(OutboundHeaders outboundHeaders);
 
 }