Run RemoteReporter's flush timer in daemon thread.

jaeger-core/src/main/java/com/uber/jaeger/reporters/RemoteReporter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Uber Technologies, Inc
+ * Copyright (c) 2017, Uber Technologies, Inc
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -31,6 +31,7 @@
 import java.util.TimerTask;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.atomic.AtomicLong;
 import lombok.ToString;
 import lombok.extern.slf4j.Slf4j;
 
@@ -47,6 +48,7 @@ public class RemoteReporter implements Reporter {
   private final Sender sender;
   private final int maxQueueSize;
   private final Metrics metrics;
+  private static final AtomicLong nextSerialNumber = new AtomicLong(0);
 
   /*
    * RemoteReporter takes a Sender object, and sends spans for a specific protocol, and transport.
@@ -59,12 +61,14 @@ public RemoteReporter(final Sender sender, int flushInterval, int maxQueueSize,
     commandQueue = new ArrayBlockingQueue<>(maxQueueSize);
 
     // start a thread to append spans
+    long serialNumber = nextSerialNumber.getAndIncrement();
     queueProcessor = new QueueProcessor();
-    queueProcessorThread = new Thread(queueProcessor);
+    queueProcessorThread =
+        new Thread(queueProcessor, "jaeger.RemoteReporter-QueueProcessor-" + serialNumber);
     queueProcessorThread.setDaemon(true);
     queueProcessorThread.start();
 
-    flushTimer = new Timer();
+    flushTimer = new Timer("jaeger.RemoteReporter-FlushTimer-" + serialNumber, true /* isDaemon */);
     flushTimer.schedule(
         new TimerTask() {
           @Override

jaeger-core/src/test/java/com/uber/jaeger/reporters/RemoteReporterTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Uber Technologies, Inc
+ * Copyright (c) 2017, Uber Technologies, Inc
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -34,6 +34,8 @@
 import java.util.List;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 public class RemoteReporterTest {
   private Reporter reporter;
@@ -89,4 +91,17 @@ public void testRemoteReporterFlushesOnClose() throws Exception {
     assertEquals(
         100L, metricsReporter.counters.get("jaeger.traces.sampled=y.state=started").longValue());
   }
+
+  @Test
+  public void testRemoteReporterFlushTimerThread() throws Exception {
+    int flushTimerThreadCount = 0;
+    for (Thread thread : Thread.getAllStackTraces().keySet()) {
+      if (!thread.getName().startsWith("jaeger.RemoteReporter-FlushTimer")) {
+        continue;
+      }
+      ++flushTimerThreadCount;
+      assertTrue(thread.isDaemon());
+    }
+    assertFalse(flushTimerThreadCount == 0);
+  }
 }