Fix race condition on loading SDK (#142)

open-telemetry · Feb 7, 2020 · a20b444 · a20b444
1 parent 7599e2f
commit a20b444
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/agent-tooling/src/main/java/io/opentelemetry/auto/tooling/AgentInstaller.java b/agent-tooling/src/main/java/io/opentelemetry/auto/tooling/AgentInstaller.java
@@ -10,6 +10,7 @@
 import static net.bytebuddy.matcher.ElementMatchers.none;
 import static net.bytebuddy.matcher.ElementMatchers.not;
 
+import io.opentelemetry.OpenTelemetry;
 import io.opentelemetry.auto.config.Config;
 import java.lang.instrument.Instrumentation;
 import java.util.ArrayList;
@@ -52,6 +53,13 @@ public static void installBytebuddyAgent(final Instrumentation inst) {
    */
   public static ResettableClassFileTransformer installBytebuddyAgent(
       final Instrumentation inst, final AgentBuilder.Listener... listeners) {
+
+    // need to trigger loading of OpenTelemetry SDK before instrumentation can possibly cause
+    // io.opentelemetry.OpenTelemetry to be loaded, since as soon as io.opentelemetry.OpenTelemetry,
+    // it looks up implementation via SPI, and if it doesn't find one, it loads the No-op
+    // implementation and it cannot be replaced later
+    OpenTelemetry.getTracerFactory();
+
     INSTRUMENTATION = inst;
 
     AgentBuilder agentBuilder =