Send initial telemetry in separate thread to reduce start-up latency.

DataDog · AlexeyKuznetsov-DD · May 28, 2025 · May 13, 2025 · May 13, 2025 · May 13, 2025
commit 14d6ea5908ddbbec4d613b18229b77ebc5752440
@@ -1,11 +1,9 @@
 package datadog.trace.bootstrap;
 
 import datadog.json.JsonWriter;
-import java.io.IOException;
 import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.TimeUnit;
 
 /** Thread safe telemetry class used to relay information about tracer activation. */
 public abstract class BootstrapInitializationTelemetry {
@@ -179,7 +177,7 @@ public void finish() {
   }
 
   public interface JsonSender {
-    void send(byte[] payload) throws IOException;
+    void send(byte[] payload);
   }
 
   public static final class ForwarderJsonSender implements JsonSender {
@@ -190,19 +188,34 @@ public static final class ForwarderJsonSender implements JsonSender {
     }
 
     @Override
-    public void send(byte[] payload) throws IOException {
-      ProcessBuilder builder = new ProcessBuilder(forwarderPath, "library_entrypoint");
+    public void send(byte[] payload) {
+      ForwarderJsonSenderThread t = new ForwarderJsonSenderThread(forwarderPath, payload);
+      t.start();
+    }
+  }
 
-      Process process = builder.start();
-      try (OutputStream out = process.getOutputStream()) {
-        out.write(payload);
-      }
+  public static final class ForwarderJsonSenderThread extends Thread {
+    private final String forwarderPath;
+    private final byte[] payload;
+
+    public ForwarderJsonSenderThread(String forwarderPath, byte[] payload) {
+      super("dd-forwarder-json-sender");
+      this.forwarderPath = forwarderPath;
+      this.payload = payload;
+    }
+
+    @Override
+    public void run() {
+      ProcessBuilder builder = new ProcessBuilder(forwarderPath, "library_entrypoint");
 
       try {
-        process.waitFor(1, TimeUnit.SECONDS);
-      } catch (InterruptedException e) {
-        // just for hygiene, reset the interrupt status
-        Thread.currentThread().interrupt();
+        Process process = builder.start();
+        try (OutputStream out = process.getOutputStream()) {
+          out.write(payload);
+        }
+      } catch (Throwable e) {
+        // We don't have a log manager here, so just print.
+        System.err.println("Failed to send telemetry: " + e.getMessage());
       }
     }
   }