svn merge -c 1482661 from trunk for HDFS-3180. Add socket timeouts to WebHdfsFileSystem.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1482662 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -258,6 +258,9 @@ Release 2.0.5-beta - UNRELEASED
     HDFS-4813. Add volatile to BlocksMap.blocks so that the replication thread
     can see the updated value.  (Jing Zhao via szetszwo)
 
+    HDFS-3180. Add socket timeouts to WebHdfsFileSystem.  (Chris Nauroth via
+    szetszwo)
+
 Release 2.0.4-alpha - 2013-04-25
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/URLUtils.java

@@ -44,8 +44,17 @@ public class URLUtils {
    */
   public static URLConnection openConnection(URL url) throws IOException {
     URLConnection connection = url.openConnection();
+    setTimeouts(connection);
+    return connection;    
+  }
+
+  /**
+   * Sets timeout parameters on the given URLConnection.
+   * 
+   * @param connection URLConnection to set
+   */
+  static void setTimeouts(URLConnection connection) {
     connection.setConnectTimeout(SOCKET_TIMEOUT);
     connection.setReadTimeout(SOCKET_TIMEOUT);
-    return connection;    
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -101,6 +101,7 @@ import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.authentication.client.AuthenticatedURL;
 import org.apache.hadoop.security.authentication.client.AuthenticationException;
 import org.apache.hadoop.security.authorize.AuthorizationException;
+import org.apache.hadoop.security.authentication.client.ConnectionConfigurator;
 import org.apache.hadoop.security.token.SecretManager.InvalidToken;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.security.token.TokenIdentifier;
@@ -126,6 +127,16 @@ public class WebHdfsFileSystem extends FileSystem
 
   /** SPNEGO authenticator */
   private static final KerberosUgiAuthenticator AUTH = new KerberosUgiAuthenticator();
+  /** Configures connections for AuthenticatedURL */
+  private static final ConnectionConfigurator CONN_CONFIGURATOR =
+    new ConnectionConfigurator() {
+      @Override
+      public HttpURLConnection configure(HttpURLConnection conn)
+          throws IOException {
+        URLUtils.setTimeouts(conn);
+        return conn;
+      }
+    };
   /** Delegation token kind */
   public static final Text TOKEN_KIND = new Text("WEBHDFS delegation");
   /** Token selector */
@@ -485,10 +496,12 @@ public class WebHdfsFileSystem extends FileSystem
           LOG.debug("open AuthenticatedURL connection");
           UserGroupInformation.getCurrentUser().checkTGTAndReloginFromKeytab();
           final AuthenticatedURL.Token authToken = new AuthenticatedURL.Token();
-          conn = new AuthenticatedURL(AUTH).openConnection(url, authToken);
+          conn = new AuthenticatedURL(AUTH, CONN_CONFIGURATOR).openConnection(
+            url, authToken);
+          URLUtils.setTimeouts(conn);
         } else {
           LOG.debug("open URL connection");
-          conn = (HttpURLConnection)url.openConnection();
+          conn = (HttpURLConnection)URLUtils.openConnection(url);
         }
       } catch (AuthenticationException e) {
         throw new IOException(e);
@@ -583,7 +596,7 @@ public class WebHdfsFileSystem extends FileSystem
       checkRetry = false;
       
       //Step 2) Submit another Http request with the URL from the Location header with data.
-      conn = (HttpURLConnection)new URL(redirect).openConnection();
+      conn = (HttpURLConnection)URLUtils.openConnection(new URL(redirect));
       conn.setRequestProperty("Content-Type", MediaType.APPLICATION_OCTET_STREAM);
       conn.setChunkedStreamingMode(32 << 10); //32kB-chunk
       connect();
@@ -606,7 +619,7 @@ public class WebHdfsFileSystem extends FileSystem
           disconnect();
   
           checkRetry = false;
-          conn = (HttpURLConnection)new URL(redirect).openConnection();
+          conn = (HttpURLConnection)URLUtils.openConnection(new URL(redirect));
           connect();
         }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsTimeouts.java

@@ -0,0 +1,322 @@
+/**
+ * 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.hdfs.web;
+
+import static org.junit.Assert.*;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.net.SocketTimeoutException;
+import java.nio.channels.SocketChannel;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.net.NetUtils;
+
+/**
+ * This test suite checks that WebHdfsFileSystem sets connection timeouts and
+ * read timeouts on its sockets, thus preventing threads from hanging
+ * indefinitely on an undefined/infinite timeout.  The tests work by starting a
+ * bogus server on the namenode HTTP port, which is rigged to not accept new
+ * connections or to accept connections but not send responses.
+ */
+public class TestWebHdfsTimeouts {
+
+  private static final Log LOG = LogFactory.getLog(TestWebHdfsTimeouts.class);
+
+  private static final int CLIENTS_TO_CONSUME_BACKLOG = 100;
+  private static final int CONNECTION_BACKLOG = 1;
+  private static final int INITIAL_SOCKET_TIMEOUT = URLUtils.SOCKET_TIMEOUT;
+  private static final int SHORT_SOCKET_TIMEOUT = 5;
+  private static final int TEST_TIMEOUT = 10000;
+
+  private List<SocketChannel> clients;
+  private WebHdfsFileSystem fs;
+  private InetSocketAddress nnHttpAddress;
+  private ServerSocket serverSocket;
+  private Thread serverThread;
+
+  @Before
+  public void setUp() throws Exception {
+    URLUtils.SOCKET_TIMEOUT = SHORT_SOCKET_TIMEOUT;
+    Configuration conf = WebHdfsTestUtil.createConf();
+    nnHttpAddress = NameNode.getHttpAddress(conf);
+    serverSocket = new ServerSocket(nnHttpAddress.getPort(), CONNECTION_BACKLOG);
+    fs = WebHdfsTestUtil.getWebHdfsFileSystem(conf);
+    clients = new ArrayList<SocketChannel>();
+    serverThread = null;
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    IOUtils.cleanup(LOG, clients.toArray(new SocketChannel[clients.size()]));
+    IOUtils.cleanup(LOG, fs);
+    if (serverSocket != null) {
+      try {
+        serverSocket.close();
+      } catch (IOException e) {
+        LOG.debug("Exception in closing " + serverSocket, e);
+      }
+    }
+    if (serverThread != null) {
+      serverThread.join();
+    }
+  }
+
+  /**
+   * Expect connect timeout, because the connection backlog is consumed.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testConnectTimeout() throws Exception {
+    consumeConnectionBacklog();
+    try {
+      fs.listFiles(new Path("/"), false);
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("connect timed out", e.getMessage());
+    }
+  }
+
+  /**
+   * Expect read timeout, because the bogus server never sends a reply.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testReadTimeout() throws Exception {
+    try {
+      fs.listFiles(new Path("/"), false);
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("Read timed out", e.getMessage());
+    }
+  }
+
+  /**
+   * Expect connect timeout on a URL that requires auth, because the connection
+   * backlog is consumed.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testAuthUrlConnectTimeout() throws Exception {
+    consumeConnectionBacklog();
+    try {
+      fs.getDelegationToken("renewer");
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("connect timed out", e.getMessage());
+    }
+  }
+
+  /**
+   * Expect read timeout on a URL that requires auth, because the bogus server
+   * never sends a reply.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testAuthUrlReadTimeout() throws Exception {
+    try {
+      fs.getDelegationToken("renewer");
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("Read timed out", e.getMessage());
+    }
+  }
+
+  /**
+   * After a redirect, expect connect timeout accessing the redirect location,
+   * because the connection backlog is consumed.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testRedirectConnectTimeout() throws Exception {
+    startSingleTemporaryRedirectResponseThread(true);
+    try {
+      fs.getFileChecksum(new Path("/file"));
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("connect timed out", e.getMessage());
+    }
+  }
+
+  /**
+   * After a redirect, expect read timeout accessing the redirect location,
+   * because the bogus server never sends a reply.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testRedirectReadTimeout() throws Exception {
+    startSingleTemporaryRedirectResponseThread(false);
+    try {
+      fs.getFileChecksum(new Path("/file"));
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("Read timed out", e.getMessage());
+    }
+  }
+
+  /**
+   * On the second step of two-step write, expect connect timeout accessing the
+   * redirect location, because the connection backlog is consumed.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testTwoStepWriteConnectTimeout() throws Exception {
+    startSingleTemporaryRedirectResponseThread(true);
+    OutputStream os = null;
+    try {
+      os = fs.create(new Path("/file"));
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("connect timed out", e.getMessage());
+    } finally {
+      IOUtils.cleanup(LOG, os);
+    }
+  }
+
+  /**
+   * On the second step of two-step write, expect read timeout accessing the
+   * redirect location, because the bogus server never sends a reply.
+   */
+  @Test(timeout=TEST_TIMEOUT)
+  public void testTwoStepWriteReadTimeout() throws Exception {
+    startSingleTemporaryRedirectResponseThread(false);
+    OutputStream os = null;
+    try {
+      os = fs.create(new Path("/file"));
+      os.close(); // must close stream to force reading the HTTP response
+      os = null;
+      fail("expected timeout");
+    } catch (SocketTimeoutException e) {
+      assertEquals("Read timed out", e.getMessage());
+    } finally {
+      IOUtils.cleanup(LOG, os);
+    }
+  }
+
+  /**
+   * Starts a background thread that accepts one and only one client connection
+   * on the server socket, sends an HTTP 307 Temporary Redirect response, and
+   * then exits.  This is useful for testing timeouts on the second step of
+   * methods that issue 2 HTTP requests (request 1, redirect, request 2).
+   * 
+   * For handling the first request, this method sets socket timeout to use the
+   * initial values defined in URLUtils.  Afterwards, it guarantees that the
+   * second request will use a very short timeout.
+   * 
+   * Optionally, the thread may consume the connection backlog immediately after
+   * receiving its one and only client connection.  This is useful for forcing a
+   * connection timeout on the second request.
+   * 
+   * On tearDown, open client connections are closed, and the thread is joined.
+   * 
+   * @param consumeConnectionBacklog boolean whether or not to consume connection
+   *   backlog and thus force a connection timeout on the second request
+   */
+  private void startSingleTemporaryRedirectResponseThread(
+      final boolean consumeConnectionBacklog) {
+    URLUtils.SOCKET_TIMEOUT = INITIAL_SOCKET_TIMEOUT;
+    serverThread = new Thread() {
+      @Override
+      public void run() {
+        Socket clientSocket = null;
+        OutputStream out = null;
+        InputStream in = null;
+        InputStreamReader isr = null;
+        BufferedReader br = null;
+        try {
+          // Accept one and only one client connection.
+          clientSocket = serverSocket.accept();
+
+          // Immediately setup conditions for subsequent connections.
+          URLUtils.SOCKET_TIMEOUT = SHORT_SOCKET_TIMEOUT;
+          if (consumeConnectionBacklog) {
+            consumeConnectionBacklog();
+          }
+
+          // Consume client's HTTP request by reading until EOF or empty line.
+          in = clientSocket.getInputStream();
+          isr = new InputStreamReader(in);
+          br = new BufferedReader(isr);
+          for (;;) {
+            String line = br.readLine();
+            if (line == null || line.isEmpty()) {
+              break;
+            }
+          }
+
+          // Write response.
+          out = clientSocket.getOutputStream();
+          out.write(temporaryRedirect().getBytes("UTF-8"));
+        } catch (IOException e) {
+          // Fail the test on any I/O error in the server thread.
+          LOG.error("unexpected IOException in server thread", e);
+          fail("unexpected IOException in server thread: " + e);
+        } finally {
+          // Clean it all up.
+          IOUtils.cleanup(LOG, br, isr, in, out);
+          IOUtils.closeSocket(clientSocket);
+        }
+      }
+    };
+    serverThread.start();
+  }
+
+  /**
+   * Consumes the test server's connection backlog by spamming non-blocking
+   * SocketChannel client connections.  We never do anything with these sockets
+   * beyond just initiaing the connections.  The method saves a reference to each
+   * new SocketChannel so that it can be closed during tearDown.  We define a
+   * very small connection backlog, but the OS may silently enforce a larger
+   * minimum backlog than requested.  To work around this, we create far more
+   * client connections than our defined backlog.
+   * 
+   * @throws IOException thrown for any I/O error
+   */
+  private void consumeConnectionBacklog() throws IOException {
+    for (int i = 0; i < CLIENTS_TO_CONSUME_BACKLOG; ++i) {
+      SocketChannel client = SocketChannel.open();
+      client.configureBlocking(false);
+      client.connect(nnHttpAddress);
+      clients.add(client);
+    }
+  }
+
+  /**
+   * Creates an HTTP 307 response with the redirect location set back to the
+   * test server's address.  HTTP is supposed to terminate newlines with CRLF, so
+   * we hard-code that instead of using the line separator property.
+   * 
+   * @return String HTTP 307 response
+   */
+  private String temporaryRedirect() {
+    return "HTTP/1.1 307 Temporary Redirect\r\n" +
+      "Location: http://" + NetUtils.getHostPortString(nnHttpAddress) + "\r\n" +
+      "\r\n";
+  }
+}