RawSocketSender.send() should try to flush the buffer after it's full

src/main/java/org/fluentd/logger/sender/RawSocketSender.java

@@ -139,11 +139,24 @@ protected boolean emit(Event event) {
         return send(bytes);
     }
 
+    private boolean flushBuffer() {
+        if (reconnector.enableReconnection(System.currentTimeMillis())) {
+            flush();
+            if (pendings.position() == 0) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     private synchronized boolean send(byte[] bytes) {
         // buffering
         if (pendings.position() + bytes.length > pendings.capacity()) {
-            LOG.error("Cannot send logs to " + server.toString());
-            return false;
+            if (!flushBuffer()) {
+                LOG.error("Cannot send logs to " + server.toString());
+                return false;
+            }
         }
         pendings.put(bytes);
 

src/test/java/org/fluentd/logger/sender/TestRawSocketSender.java

@@ -333,4 +333,79 @@ public void process(MessagePack msgpack, Socket socket) throws IOException {
         assertTrue(event.data.keySet().contains("key0"));
         assertTrue(event.data.values().contains("v3"));
     }
+
+    @Test
+    public void testReconnectAfterBufferFull() throws Exception {
+        final CountDownLatch bufferFull = new CountDownLatch(1);
+
+        // start mock fluentd
+        int port = MockFluentd.randomPort(); // Use a random port available
+        final List<Event> elist = new ArrayList<Event>();
+        final MockFluentd fluentd = new MockFluentd(port, new MockFluentd.MockProcess() {
+            public void process(MessagePack msgpack, Socket socket) throws IOException {
+                try {
+                    BufferedInputStream in = new BufferedInputStream(socket.getInputStream());
+                    Unpacker unpacker = msgpack.createUnpacker(in);
+                    while (true) {
+                        Event e = unpacker.read(Event.class);
+                        elist.add(e);
+                    }
+                } catch (EOFException e) {
+                    // ignore
+                } finally {
+                    socket.close();
+                }
+            }
+        });
+
+        ExecutorService executor = Executors.newSingleThreadExecutor();
+        executor.execute(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    bufferFull.await(20, TimeUnit.SECONDS);
+                    fluentd.start();
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+
+        // start senders
+        Sender sender = new RawSocketSender("localhost", port);
+        String tag = "tag";
+        int i;
+        for (i = 0; i < 1000000; i++) {     // Enough to fill the sender's buffer
+            Map<String, Object> record = new HashMap<String, Object>();
+            record.put("num", i);
+            record.put("str", "name" + i);
+
+            if (bufferFull.getCount() > 0) {
+                // Fill the sender's buffer
+                if (!sender.emit(tag, record)) {
+                    // Buffer full. Need to recover the fluentd
+                    bufferFull.countDown();
+                    Thread.sleep(2000);
+                }
+            }
+            else {
+                // Flush the sender's buffer after the fluentd starts
+                sender.emit(tag, record);
+                break;
+            }
+        }
+
+        // close sender sockets
+        sender.close();
+
+        // wait for unpacking event data on fluentd
+        Thread.sleep(2000);
+
+        // close mock server sockets
+        fluentd.close();
+
+        // check data
+        assertEquals(0, bufferFull.getCount());
+        assertEquals(i, elist.size());
+    }
 }

src/test/java/org/fluentd/logger/util/MockFluentd.java

@@ -84,15 +84,16 @@ private static Object toObject(Unpacker u, Value v) {
         }
     }
 
+    private final int port;
     private ServerSocket serverSocket;
 
     private MockProcess process;
 
     private AtomicBoolean started = new AtomicBoolean(false);
     private AtomicBoolean finished = new AtomicBoolean(false);
 
-    public MockFluentd(int port, MockProcess mockProcess) throws IOException {
-        serverSocket = new ServerSocket(port);
+    public MockFluentd(int port, MockProcess mockProcess) {
+        this.port = port;
         process = mockProcess;
     }
 
@@ -112,6 +113,13 @@ public static int randomPort() throws IOException {
 
 
     public void run() {
+        try {
+            serverSocket = new ServerSocket(port);
+        } catch (IOException e) {
+            e.printStackTrace();
+            throw new RuntimeException("Failed to start MockFluentd process", e);
+        }
+
         _logger.debug("Started MockFluentd port:" + serverSocket.getLocalPort());
 
         while (!finished.get()) {