Log SenderExceptions the first time they occur in a row

jaeger-core/src/main/java/io/jaegertracing/internal/reporters/RemoteReporter.java

@@ -21,6 +21,8 @@
 import io.jaegertracing.internal.senders.SenderResolver;
 import io.jaegertracing.spi.Reporter;
 import io.jaegertracing.spi.Sender;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
 import java.util.concurrent.ArrayBlockingQueue;
@@ -166,17 +168,29 @@ public void execute() throws SenderException {
   @ToString
   class QueueProcessor implements Runnable {
     private boolean open = true;
+    private final Set<Class<?>> commandFailedBefore = new HashSet<Class<?>>();
 
     @Override
     public void run() {
       while (open) {
         try {
           RemoteReporter.Command command = commandQueue.take();
+          Class<? extends Command> commandClass = command.getClass();
+          boolean failedBefore = commandFailedBefore.contains(commandClass);
 
           try {
             command.execute();
+            if (failedBefore) {
+              log.info(commandClass.getSimpleName() + " is working again!");
+              commandFailedBefore.remove(commandClass);
+            }
           } catch (SenderException e) {
             metrics.reporterFailure.inc(e.getDroppedSpanCount());
+            if (!failedBefore) {
+              log.warn(commandClass.getSimpleName()
+                      + " execution failed! Repeated errors of this command will not be logged.", e);
+              commandFailedBefore.add(commandClass);
+            }
           }
         } catch (Exception e) {
           log.error("QueueProcessor error:", e);

jaeger-core/src/test/java/io/jaegertracing/internal/reporters/RemoteReporterTest.java

@@ -22,6 +22,8 @@
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.ArgumentMatchers.nullable;
+import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
@@ -39,15 +41,21 @@
 import io.jaegertracing.spi.Reporter;
 import io.jaegertracing.spi.Sender;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.CyclicBarrier;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Consumer;
+
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
 import org.mockito.ArgumentMatcher;
+import org.mockito.ArgumentMatchers;
 import org.slf4j.LoggerFactory;
 
 public class RemoteReporterTest {
@@ -215,15 +223,8 @@ public void testCloseWhenQueueFull() {
   @Test
   public void testCloseLogSenderException() throws SenderException {
 
-    // set up mocking
-    ch.qos.logback.classic.Logger root =
-        (ch.qos.logback.classic.Logger) LoggerFactory
-          .getLogger(ch.qos.logback.classic.Logger.ROOT_LOGGER_NAME);
-
-    @SuppressWarnings("unchecked") final Appender<ILoggingEvent> mockAppender =
-        mock(Appender.class);
-    when(mockAppender.getName()).thenReturn("MOCK");
-    root.addAppender(mockAppender);
+    Appender<ILoggingEvent> mockAppender = mockLogger(e -> {
+    });
 
     final Sender mockedSender = mock(Sender.class);
     when(mockedSender.close()).thenThrow(SenderException.class);
@@ -322,6 +323,74 @@ public int flush() throws SenderException {
     assertEquals("mySpan", (sender.getReceived().get(0)).getOperationName());
   }
 
+  @Test
+  public void testFlushErrorsLoggedJustOnce() throws InterruptedException {
+
+    Object logMonitor = new Object();
+    AtomicReference<String> logMsg = new AtomicReference<>(null);
+    mockLogger(e -> {
+      synchronized (logMonitor) {
+        logMsg.set(e.getFormattedMessage());
+        logMonitor.notifyAll();
+      }
+    });
+
+    class FailingSender extends InMemorySender {
+      private final AtomicInteger flushCounter = new AtomicInteger(0);
+
+      @Override
+      public int flush() throws SenderException {
+        int i = super.flush();
+        switch (flushCounter.getAndIncrement()) {
+          case 1:
+          case 2:
+          case 3:
+            throw new SenderException("test1", super.flush());
+          default:
+            return i;
+        }
+      }
+
+      private String awaitMessage(AtomicReference<String> ref) throws InterruptedException {
+        synchronized (logMonitor) {
+          while (ref.get() == null) {
+            logMonitor.wait();
+          }
+          return ref.getAndSet(null);
+        }
+      }
+    }
+
+    FailingSender sender = new FailingSender();
+
+    RemoteReporter remoteReporter = new Builder()
+        .withSender(sender)
+        .withFlushInterval(Integer.MAX_VALUE)
+        .withMaxQueueSize(maxQueueSize)
+        .withMetrics(metrics)
+        .build();
+    tracer = new JaegerTracer.Builder("test-remote-reporter")
+        .withReporter(remoteReporter)
+        .withSampler(new ConstSampler(true))
+        .withMetrics(metrics)
+        .build();
+
+    tracer.buildSpan("mySpan").start().finish();
+    remoteReporter.flush();
+
+    tracer.buildSpan("mySpan").start().finish();
+    remoteReporter.flush();
+
+    assertEquals("FlushCommand execution failed! Repeated errors of this command will not be logged.",
+            sender.awaitMessage(logMsg));
+
+    remoteReporter.flush();
+    remoteReporter.flush();
+    remoteReporter.flush();
+    assertEquals("FlushCommand is working again!", sender.awaitMessage(logMsg));
+
+  }
+
   @Test
   public void testUpdateSuccessMetricWhenAppendFlushed() throws InterruptedException {
     int totalSpans = 3;
@@ -396,4 +465,21 @@ public int append(JaegerSpan span) throws SenderException {
   private JaegerSpan newSpan() {
     return tracer.buildSpan("x").start();
   }
+
+  private static Appender<ILoggingEvent> mockLogger(Consumer<ILoggingEvent> append) {
+    ch.qos.logback.classic.Logger root =
+            (ch.qos.logback.classic.Logger) LoggerFactory
+                    .getLogger(ch.qos.logback.classic.Logger.ROOT_LOGGER_NAME);
+
+    @SuppressWarnings("unchecked")
+    final Appender<ILoggingEvent> mockAppender = mock(Appender.class);
+    when(mockAppender.getName()).thenReturn("MOCK");
+    doAnswer(i -> {
+      append.accept(i.getArgument(0));
+      return null;
+    }).when(mockAppender).doAppend(ArgumentMatchers.any(ILoggingEvent.class));
+    root.addAppender(mockAppender);
+
+    return mockAppender;
+  }
 }