/**
* 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.tajo.webapp;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.security.UserGroupInformation;
import org.mortbay.jetty.Connector;
import org.mortbay.jetty.Handler;
import org.mortbay.jetty.Server;
import org.mortbay.jetty.SessionIdManager;
import org.mortbay.jetty.handler.ContextHandlerCollection;
import org.mortbay.jetty.nio.SelectChannelConnector;
import org.mortbay.jetty.servlet.*;
import org.mortbay.jetty.webapp.WebAppContext;
import org.mortbay.thread.QueuedThreadPool;
import org.mortbay.util.MultiException;
import javax.servlet.http.HttpServlet;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.BindException;
import java.net.URL;
import java.util.*;
/**
* This class is borrowed from Hadoop and is simplified to our objective.
*/
public class HttpServer {
private static final Log LOG = LogFactory.getLog(HttpServer.class);
protected final Server webServer;
protected final Connector listener;
protected final WebAppContext webAppContext;
protected final boolean findPort;
protected final Map<Context, Boolean> defaultContexts =
new HashMap<Context, Boolean>();
protected final List<String> filterNames = new ArrayList<String>();
private static final int MAX_RETRIES = 10;
private final boolean listenerStartedExternally;
static final String STATE_DESCRIPTION_ALIVE = " - alive";
static final String STATE_DESCRIPTION_NOT_LIVE = " - not live";
public HttpServer(String name, String bindAddress, int port,
boolean findPort, Connector connector, Configuration conf,
String[] pathSpecs) throws IOException {
this.webServer = new Server();
this.findPort = findPort;
if (connector == null) {
listenerStartedExternally = false;
listener = createBaseListener(conf);
listener.setHost(bindAddress);
listener.setPort(port);
} else {
listenerStartedExternally = true;
listener = connector;
}
webServer.addConnector(listener);
SessionIdManager sessionIdManager = new HashSessionIdManager(new Random(System.currentTimeMillis()));
webServer.setSessionIdManager(sessionIdManager);
int maxThreads = conf.getInt("tajo.http.maxthreads", -1);
// If HTTP_MAX_THREADS is not configured, QueueThreadPool() will use the
// default value (currently 250).
QueuedThreadPool threadPool = maxThreads == -1 ? new QueuedThreadPool()
: new QueuedThreadPool(maxThreads);
webServer.setThreadPool(threadPool);
final String appDir = getWebAppsPath(name);
ContextHandlerCollection contexts = new ContextHandlerCollection();
webAppContext = new WebAppContext();
webAppContext.setDisplayName(name);
webAppContext.setContextPath("/");
webAppContext.setResourceBase(appDir + "/" + name);
webAppContext.setDescriptor(appDir + "/" + name + "/WEB-INF/web.xml");
contexts.addHandler(webAppContext);
webServer.setHandler(contexts);
addDefaultApps(contexts, appDir, conf);
}
/**
* Create a required listener for the Jetty instance listening on the port
* provided. This wrapper and all subclasses must create at least one
* listener.
*/
public Connector createBaseListener(Configuration conf) throws IOException {
return HttpServer.createDefaultChannelConnector();
}
static Connector createDefaultChannelConnector() {
SelectChannelConnector ret = new SelectChannelConnector();
ret.setLowResourceMaxIdleTime(10000);
ret.setAcceptQueueSize(128);
ret.setResolveNames(false);
ret.setUseDirectBuffers(false);
return ret;
}
/**
* Add default apps.
*
* @param appDir
* The application directory
* @throws IOException
*/
protected void addDefaultApps(ContextHandlerCollection parent,
final String appDir, Configuration conf) throws IOException {
// set up the context for "/logs/" if "hadoop.log.dir" property is defined.
String logDir = System.getProperty("tajo.log.dir");
if (logDir != null) {
Context logContext = new Context(parent, "/logs");
logContext.setResourceBase(logDir);
//logContext.addServlet(AdminAuthorizedServlet.class, "/*");
logContext.setDisplayName("logs");
defaultContexts.put(logContext, true);
}
// set up the context for "/static/*"
Context staticContext = new Context(parent, "/static");
staticContext.setResourceBase(appDir + "/static");
staticContext.addServlet(DefaultServlet.class, "/*");
staticContext.setDisplayName("static");
defaultContexts.put(staticContext, true);
}
public void addContext(Context ctxt, boolean isFiltered)
throws IOException {
webServer.addHandler(ctxt);
defaultContexts.put(ctxt, isFiltered);
}
/**
* Add a context
* @param pathSpec The path spec for the context
* @param dir The directory containing the context
* @param isFiltered if true, the servlet is added to the filter path mapping
* @throws IOException
*/
protected void addContext(String pathSpec, String dir, boolean isFiltered) throws IOException {
if (0 == webServer.getHandlers().length) {
throw new RuntimeException("Couldn't find handler");
}
WebAppContext webAppCtx = new WebAppContext();
webAppCtx.setContextPath(pathSpec);
webAppCtx.setWar(dir);
addContext(webAppCtx, true);
}
/**
* Set a value in the webapp context. These values are available to the jsp
* pages as "application.getAttribute(name)".
* @param name The name of the attribute
* @param value The value of the attribute
*/
public void setAttribute(String name, Object value) {
webAppContext.setAttribute(name, value);
}
/**
* Add a servlet in the server.
* @param name The name of the servlet (can be passed as null)
* @param pathSpec The path spec for the servlet
* @param clazz The servlet class
*/
public void addServlet(String name, String pathSpec,
Class<? extends HttpServlet> clazz) {
addInternalServlet(name, pathSpec, clazz, false);
addFilterPathMapping(pathSpec, webAppContext);
}
/**
* Add an internal servlet in the server, specifying whether or not to
* protect with Kerberos authentication.
* Note: This method is to be used for adding servlets that facilitate
* internal communication and not for user facing functionality. For
* servlets added using this method, filters (except internal Kerberized
* filters) are not enabled.
*
* @param name The name of the servlet (can be passed as null)
* @param pathSpec The path spec for the servlet
* @param clazz The servlet class
*/
public void addInternalServlet(String name, String pathSpec,
Class<? extends HttpServlet> clazz, boolean requireAuth) {
ServletHolder holder = new ServletHolder(clazz);
if (name != null) {
holder.setName(name);
}
webAppContext.addServlet(holder, pathSpec);
if(requireAuth && UserGroupInformation.isSecurityEnabled()) {
LOG.info("Adding Kerberos filter to " + name);
ServletHandler handler = webAppContext.getServletHandler();
FilterMapping fmap = new FilterMapping();
fmap.setPathSpec(pathSpec);
fmap.setFilterName("krb5Filter");
fmap.setDispatches(Handler.ALL);
handler.addFilterMapping(fmap);
}
}
/**
* Add the path spec to the filter path mapping.
* @param pathSpec The path spec
* @param webAppCtx The WebApplicationContext to add to
*/
protected void addFilterPathMapping(String pathSpec,
Context webAppCtx) {
ServletHandler handler = webAppCtx.getServletHandler();
for(String name : filterNames) {
FilterMapping fmap = new FilterMapping();
fmap.setPathSpec(pathSpec);
fmap.setFilterName(name);
fmap.setDispatches(Handler.ALL);
handler.addFilterMapping(fmap);
}
}
protected String getWebAppsPath(String name) throws FileNotFoundException {
URL url = getClass().getClassLoader().getResource("webapps/" + name);
if (url == null) {
throw new FileNotFoundException("webapps/" + name + " not found in CLASSPATH");
}
String urlString = url.toString();
return urlString.substring(0, urlString.lastIndexOf('/'));
}
/**
* Get the value in the webapp context.
* @param name The name of the attribute
* @return The value of the attribute
*/
public Object getAttribute(String name) {
return webAppContext.getAttribute(name);
}
/**
* Get the port that the server is on
* @return the port
*/
public int getPort() {
return webServer.getConnectors()[0].getLocalPort();
}
/**
* Set the min, max number of worker threads (simultaneous connections).
*/
public void setThreads(int min, int max) {
QueuedThreadPool pool = (QueuedThreadPool) webServer.getThreadPool() ;
pool.setMinThreads(min);
pool.setMaxThreads(max);
}
/**
* Start the server. Does not wait for the server to start.
*/
public void start() throws IOException {
try {
if (listenerStartedExternally) { // Expect that listener was started
// securely
if (listener.getLocalPort() == -1) // ... and verify
throw new Exception("Exepected webserver's listener to be started "
+ "previously but wasn't");
// And skip all the port rolling issues.
webServer.start();
} else {
int port;
int oriPort = listener.getPort(); // The original requested port
while (true) {
try {
port = webServer.getConnectors()[0].getLocalPort();
LOG.debug("Port returned by webServer.getConnectors()[0]."
+ "getLocalPort() before open() is " + port
+ ". Opening the listener on " + oriPort);
listener.open();
port = listener.getLocalPort();
LOG.debug("listener.getLocalPort() returned "
+ listener.getLocalPort()
+ " webServer.getConnectors()[0].getLocalPort() returned "
+ webServer.getConnectors()[0].getLocalPort());
// Workaround to handle the problem reported in HADOOP-4744
if (port < 0) {
Thread.sleep(100);
int numRetries = 1;
while (port < 0) {
LOG.warn("listener.getLocalPort returned " + port);
if (numRetries++ > MAX_RETRIES) {
throw new Exception(" listener.getLocalPort is returning "
+ "less than 0 even after " + numRetries + " resets");
}
for (int i = 0; i < 2; i++) {
LOG.info("Retrying listener.getLocalPort()");
port = listener.getLocalPort();
if (port > 0) {
break;
}
Thread.sleep(200);
}
if (port > 0) {
break;
}
LOG.info("Bouncing the listener");
listener.close();
Thread.sleep(1000);
listener.setPort(oriPort == 0 ? 0 : (oriPort += 1));
listener.open();
Thread.sleep(100);
port = listener.getLocalPort();
}
} // Workaround end
LOG.info("Jetty bound to port " + port);
webServer.start();
break;
} catch (IOException ex) {
// if this is a bind exception,
// then try the next port number.
if (ex instanceof BindException) {
if (!findPort) {
BindException be = new BindException("Port in use: "
+ listener.getHost() + ":" + listener.getPort());
be.initCause(ex);
throw be;
}
} else {
LOG.info("HttpServer.start() threw a non Bind IOException");
throw ex;
}
} catch (MultiException ex) {
LOG.info("HttpServer.start() threw a MultiException");
throw ex;
}
listener.setPort((oriPort += 1));
}
}
// Make sure there is no handler failures.
Handler[] handlers = webServer.getHandlers();
for (int i = 0; i < handlers.length; i++) {
if (handlers[i].isFailed()) {
throw new IOException(
"Problem in starting http server. Server handlers failed");
}
}
} catch (IOException e) {
throw e;
} catch (InterruptedException e) {
throw (IOException) new InterruptedIOException(
"Interrupted while starting HTTP server").initCause(e);
} catch (Exception e) {
throw new IOException("Problem starting http server", e);
}
}
/**
* stop the server
*/
public void stop() throws Exception {
MultiException exception = null;
try {
listener.close();
} catch (Exception e) {
LOG.error(
"Error while stopping listener for webapp"
+ webAppContext.getDisplayName(), e);
exception = addMultiException(exception, e);
}
try {
// clear & stop webAppContext attributes to avoid memory leaks.
webAppContext.clearAttributes();
webAppContext.stop();
} catch (Exception e) {
LOG.error("Error while stopping web app context for webapp "
+ webAppContext.getDisplayName(), e);
exception = addMultiException(exception, e);
}
try {
webServer.stop();
} catch (Exception e) {
LOG.error(
"Error while stopping web server for webapp "
+ webAppContext.getDisplayName(), e);
exception = addMultiException(exception, e);
}
if (exception != null) {
exception.ifExceptionThrow();
}
}
private MultiException addMultiException(MultiException exception, Exception e) {
if (exception == null) {
exception = new MultiException();
}
exception.add(e);
return exception;
}
public void join() throws InterruptedException {
webServer.join();
}
/**
* Test for the availability of the web server
*
* @return true if the web server is started, false otherwise
*/
public boolean isAlive() {
return webServer != null && webServer.isStarted();
}
/**
* Return the host and port of the HttpServer, if live
*
* @return the classname and any HTTP URL
*/
@Override
public String toString() {
return listener != null ? ("HttpServer at http://" + listener.getHost()
+ ":" + listener.getLocalPort() + "/" + (isAlive() ? STATE_DESCRIPTION_ALIVE
: STATE_DESCRIPTION_NOT_LIVE))
: "Inactive HttpServer";
}
}