Do not switch to agent telemetry client on detecting agent telemetry endpoint availability when intake client is preferred (#6644)

nikita-tkachenko-datadog · web-flow · commit a3eb7336dfd6 · 2024-02-09T15:16:37.000+01:00
diff --git a/telemetry/src/main/java/datadog/telemetry/TelemetryRouter.java b/telemetry/src/main/java/datadog/telemetry/TelemetryRouter.java
@@ -12,9 +12,8 @@ public class TelemetryRouter {
 
   private final DDAgentFeaturesDiscovery ddAgentFeaturesDiscovery;
   private final TelemetryClient agentClient;
-
   private final TelemetryClient intakeClient;
-
+  private final boolean useIntakeClientByDefault;
   private TelemetryClient currentClient;
   private boolean errorReported;
 
@@ -26,6 +25,7 @@ public TelemetryRouter(
     this.ddAgentFeaturesDiscovery = ddAgentFeaturesDiscovery;
     this.agentClient = agentClient;
     this.intakeClient = intakeClient;
+    this.useIntakeClientByDefault = useIntakeClientByDefault;
     this.currentClient = useIntakeClientByDefault ? intakeClient : agentClient;
   }
 
@@ -50,12 +50,12 @@ public TelemetryClient.Result sendRequest(TelemetryRequest request) {
       if (requestFailed) {
         reportErrorOnce(currentClient.getUrl(), result);
       }
-      if (agentSupportsTelemetryProxy || requestFailed) {
+      if ((agentSupportsTelemetryProxy && !useIntakeClientByDefault) || requestFailed) {
         errorReported = false;
-        if (agentSupportsTelemetryProxy) {
-          log.info("Agent Telemetry endpoint is now available. Telemetry will be sent to Agent.");
-        } else {
+        if (requestFailed) {
           log.info("Intake Telemetry endpoint failed. Telemetry will be sent to Agent.");
+        } else {
+          log.info("Agent Telemetry endpoint is now available. Telemetry will be sent to Agent.");
         }
         currentClient = agentClient;
       }
diff --git a/telemetry/src/test/groovy/datadog/telemetry/TelemetryRouterSpecification.groovy b/telemetry/src/test/groovy/datadog/telemetry/TelemetryRouterSpecification.groovy
@@ -130,7 +130,7 @@ class TelemetryRouterSpecification extends Specification {
     500        | _
   }
 
-  def 'use Intake client from the start if configured to do so'() {
+  def 'when configured to prefer Intake: use Intake client from the start'() {
     Request request
 
     setup:
@@ -147,6 +147,56 @@ class TelemetryRouterSpecification extends Specification {
     request.header(apiKeyHeader) == apiKey
   }
 
+  def 'when configured to prefer Intake: do not switch to Agent if Intake request succeeds, even if Agent supports telemetry proxy'() {
+    Request request
+
+    setup:
+    def telemetryRouter = new TelemetryRouter(ddAgentFeaturesDiscovery, agentTelemetryClient, intakeTelemetryClient, true)
+
+    when:
+    telemetryRouter.sendRequest(dummyRequest())
+
+    then:
+    1 * ddAgentFeaturesDiscovery.discoverIfOutdated()
+    1 * ddAgentFeaturesDiscovery.supportsTelemetryProxy() >> true
+    1 * okHttpClient.newCall(_) >> { args -> request = args[0]; mockResponse(200) }
+    request.url() == intakeUrl
+    request.header(apiKeyHeader) == apiKey
+
+    when:
+    telemetryRouter.sendRequest(dummyRequest())
+
+    then:
+    1 * okHttpClient.newCall(_) >> { args -> request = args[0]; mockResponse(200) }
+    request.url() == intakeUrl
+    request.header(apiKeyHeader) == apiKey
+  }
+
+  def 'when configured to prefer Intake: switch to Agent if Intake request fails'() {
+    Request request
+
+    setup:
+    def telemetryRouter = new TelemetryRouter(ddAgentFeaturesDiscovery, agentTelemetryClient, intakeTelemetryClient, true)
+
+    when:
+    telemetryRouter.sendRequest(dummyRequest())
+
+    then:
+    1 * ddAgentFeaturesDiscovery.discoverIfOutdated()
+    1 * ddAgentFeaturesDiscovery.supportsTelemetryProxy() >> true
+    1 * okHttpClient.newCall(_) >> { args -> request = args[0]; mockResponse(403) }
+    request.url() == intakeUrl
+    request.header(apiKeyHeader) == apiKey
+
+    when:
+    telemetryRouter.sendRequest(dummyRequest())
+
+    then:
+    1 * okHttpClient.newCall(_) >> { args -> request = args[0]; mockResponse(200) }
+    request.url() == agentTelemetryUrl
+    request.header(apiKeyHeader) == null
+  }
+
   def 'do not switch to Intake when Agent stops supporting telemetry proxy but accepts telemetry requests'() {
     Request request
 
