HBASE-27782 During SSL handshake error, netty complains that exceptio…

…nCaught() was not handled (apache#5305)

Signed-off-by: Bryan Beaudreault <bbeaudreault@apache.org>

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BufferCallBeforeInitHandler.java

@@ -20,7 +20,10 @@
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import javax.net.ssl.SSLException;
 import org.apache.yetus.audience.InterfaceAudience;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import org.apache.hbase.thirdparty.io.netty.channel.ChannelDuplexHandler;
 import org.apache.hbase.thirdparty.io.netty.channel.ChannelHandlerContext;
@@ -33,6 +36,8 @@
 @InterfaceAudience.Private
 class BufferCallBeforeInitHandler extends ChannelDuplexHandler {
 
+  private static final Logger LOG = LoggerFactory.getLogger(BufferCallBeforeInitHandler.class);
+
   static final String NAME = "BufferCall";
 
   private enum BufferCallAction {
@@ -93,20 +98,50 @@ public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exc
           for (Call call : id2Call.values()) {
             ctx.write(call);
           }
+          ctx.flush();
+          ctx.pipeline().remove(this);
           break;
         case FAIL:
           for (Call call : id2Call.values()) {
             call.setException(bcEvt.error);
           }
+          // here we do not remove us from the pipeline, for receiving possible exceptions and log
+          // it, especially the ssl exceptions, to prevent it reaching the tail of the pipeline and
+          // generate a confusing netty WARN
           break;
       }
-      ctx.flush();
-      ctx.pipeline().remove(this);
     } else if (evt instanceof CallEvent) {
       // just remove the call for now until we add other call event other than timeout and cancel.
       id2Call.remove(((CallEvent) evt).call.id);
     } else {
       ctx.fireUserEventTriggered(evt);
     }
   }
+
+  private boolean isSslError(Throwable cause) {
+    Throwable error = cause;
+    do {
+      if (error instanceof SSLException) {
+        return true;
+      }
+      error = error.getCause();
+    } while (error != null);
+    return false;
+  }
+
+  @Override
+  public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+    if (isSslError(cause)) {
+      // this should have been logged in other places, see HBASE-27782 for more details.
+      // here we just log it with debug and tell users that this is not a critical problem,
+      // otherwise if we just pass it through the pipeline, it will lead to a confusing
+      // "An exceptionCaught() event was fired, and it reached at the tail of the pipeline"
+      LOG.debug(
+        "got ssl exception, which should have already been proceeded, log it here to"
+          + " prevent it being passed to netty's TailContext and trigger a confusing WARN message",
+        cause);
+    } else {
+      ctx.fireExceptionCaught(cause);
+    }
+  }
 }

hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestTLSHandshadeFailure.java

@@ -0,0 +1,163 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.ipc;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.startsWith;
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.Random;
+import java.util.concurrent.atomic.AtomicReference;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.Waiter;
+import org.apache.hadoop.hbase.client.MetricsConnection.CallStats;
+import org.apache.hadoop.hbase.io.crypto.tls.X509Util;
+import org.apache.hadoop.hbase.net.Address;
+import org.apache.hadoop.hbase.security.User;
+import org.apache.hadoop.hbase.testclassification.ClientTests;
+import org.apache.hadoop.hbase.testclassification.SmallTests;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.hbase.thirdparty.com.google.common.io.Closeables;
+import org.apache.hbase.thirdparty.io.netty.handler.ssl.NotSslRecordException;
+
+/**
+ * A simple UT to make sure that we do not leak the SslExceptions to netty's TailContext, where it
+ * will generate a confusing WARN message.
+ * <p>
+ * See HBASE-27782 for more details.
+ */
+@Category({ ClientTests.class, SmallTests.class })
+public class TestTLSHandshadeFailure {
+
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+    HBaseClassTestRule.forClass(TestTLSHandshadeFailure.class);
+
+  private static final Logger LOG = LoggerFactory.getLogger(TestTLSHandshadeFailure.class);
+
+  private final Configuration conf = HBaseConfiguration.create();
+
+  // use a pre set seed to make the random bytes stable
+  private final Random rand = new Random(1);
+
+  private ServerSocket server;
+
+  private Thread serverThread;
+
+  private NettyRpcClient client;
+
+  private org.apache.logging.log4j.core.Appender mockAppender;
+
+  private void serve() {
+    Socket socket = null;
+    try {
+      socket = server.accept();
+      byte[] bytes = new byte[128];
+      rand.nextBytes(bytes);
+      socket.getOutputStream().write(bytes);
+      socket.getOutputStream().flush();
+    } catch (Exception e) {
+      LOG.warn("failed to process request", e);
+    } finally {
+      if (socket != null) {
+        try {
+          socket.close();
+        } catch (IOException e1) {
+          LOG.warn("failed to close socket");
+        }
+      }
+    }
+  }
+
+  @Before
+  public void setUp() throws IOException {
+    server = new ServerSocket(0);
+    serverThread = new Thread(this::serve);
+    serverThread.setDaemon(true);
+    serverThread.setName("Error-Server-Thread");
+    serverThread.start();
+    conf.setBoolean(X509Util.HBASE_CLIENT_NETTY_TLS_ENABLED, true);
+    client = new NettyRpcClient(conf);
+
+    mockAppender = mock(org.apache.logging.log4j.core.Appender.class);
+    when(mockAppender.getName()).thenReturn("mockAppender");
+    when(mockAppender.isStarted()).thenReturn(true);
+    ((org.apache.logging.log4j.core.Logger) org.apache.logging.log4j.LogManager
+      .getLogger(BufferCallBeforeInitHandler.class)).addAppender(mockAppender);
+  }
+
+  @After
+  public void tearDown() throws IOException {
+    ((org.apache.logging.log4j.core.Logger) org.apache.logging.log4j.LogManager
+      .getLogger(BufferCallBeforeInitHandler.class)).removeAppender(mockAppender);
+    Closeables.close(client, true);
+    Closeables.close(server, true);
+  }
+
+  @Test
+  public void test() throws Exception {
+    AtomicReference<org.apache.logging.log4j.Level> level = new AtomicReference<>();
+    AtomicReference<String> msg = new AtomicReference<String>();
+    doAnswer(new Answer<Void>() {
+
+      @Override
+      public Void answer(InvocationOnMock invocation) throws Throwable {
+        org.apache.logging.log4j.core.LogEvent logEvent =
+          invocation.getArgument(0, org.apache.logging.log4j.core.LogEvent.class);
+        level.set(logEvent.getLevel());
+        msg.set(logEvent.getMessage().getFormattedMessage());
+        return null;
+      }
+    }).when(mockAppender).append(any());
+    ConnectionId id = new ConnectionId(User.getCurrent(), "test",
+      Address.fromParts("127.0.0.1", server.getLocalPort()));
+    NettyRpcConnection conn = client.createConnection(id);
+    BlockingRpcCallback<Call> done = new BlockingRpcCallback<>();
+    Call call = new Call(1, null, null, null, null, 0, 0, done, new CallStats());
+    HBaseRpcController hrc = new HBaseRpcControllerImpl();
+    conn.sendRequest(call, hrc);
+    done.get();
+    assertThat(call.error, instanceOf(NotSslRecordException.class));
+    Waiter.waitFor(conf, 5000, () -> msg.get() != null);
+    verify(mockAppender).append(any());
+    // make sure that it has been logged by BufferCallBeforeInitHandler
+    assertEquals(org.apache.logging.log4j.Level.DEBUG, level.get());
+    assertThat(msg.get(),
+      startsWith("got ssl exception, which should have already been proceeded"));
+  }
+}