/projects/tomcat-7.0.2/java/org/apache/catalina/tribes/group/GroupChannel.java
Java | 684 lines | 361 code | 63 blank | 260 comment | 76 complexity | 379eb864b6301cf520ca04d3a7a656ee MD5 | raw file
- /*
- * 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.catalina.tribes.group;
- import java.io.Serializable;
- import java.util.ArrayList;
- import java.util.Iterator;
- import org.apache.catalina.tribes.ByteMessage;
- import org.apache.catalina.tribes.Channel;
- import org.apache.catalina.tribes.ChannelException;
- import org.apache.catalina.tribes.ChannelInterceptor;
- import org.apache.catalina.tribes.ChannelListener;
- import org.apache.catalina.tribes.ChannelMessage;
- import org.apache.catalina.tribes.ChannelReceiver;
- import org.apache.catalina.tribes.ChannelSender;
- import org.apache.catalina.tribes.ErrorHandler;
- import org.apache.catalina.tribes.ManagedChannel;
- import org.apache.catalina.tribes.Member;
- import org.apache.catalina.tribes.MembershipListener;
- import org.apache.catalina.tribes.MembershipService;
- import org.apache.catalina.tribes.group.interceptors.MessageDispatchInterceptor;
- import org.apache.catalina.tribes.io.ChannelData;
- import org.apache.catalina.tribes.io.XByteBuffer;
- import org.apache.catalina.tribes.UniqueId;
- import org.apache.catalina.tribes.Heartbeat;
- import org.apache.catalina.tribes.io.BufferPool;
- import org.apache.catalina.tribes.RemoteProcessException;
- import org.apache.catalina.tribes.util.Logs;
- import org.apache.catalina.tribes.util.Arrays;
- import org.apache.juli.logging.Log;
- import org.apache.juli.logging.LogFactory;
- /**
- * The default implementation of a Channel.<br>
- * The GroupChannel manages the replication channel. It coordinates
- * message being sent and received with membership announcements.
- * The channel has an chain of interceptors that can modify the message or perform other logic.<br>
- * It manages a complete group, both membership and replication.
- * @author Filip Hanik
- * @version $Id: GroupChannel.java 939305 2010-04-29 13:43:39Z kkolinko $
- */
- public class GroupChannel extends ChannelInterceptorBase implements ManagedChannel {
- private static final Log log = LogFactory.getLog(GroupChannel.class);
- /**
- * Flag to determine if the channel manages its own heartbeat
- * If set to true, the channel will start a local thread for the heart beat.
- */
- protected boolean heartbeat = true;
- /**
- * If <code>heartbeat == true</code> then how often do we want this
- * heartbeat to run. default is one minute
- */
- protected long heartbeatSleeptime = 5*1000;//every 5 seconds
- /**
- * Internal heartbeat thread
- */
- protected HeartbeatThread hbthread = null;
- /**
- * The <code>ChannelCoordinator</code> coordinates the bottom layer components:<br>
- * - MembershipService<br>
- * - ChannelSender <br>
- * - ChannelReceiver<br>
- */
- protected ChannelCoordinator coordinator = new ChannelCoordinator();
- /**
- * The first interceptor in the interceptor stack.
- * The interceptors are chained in a linked list, so we only need a reference to the
- * first one
- */
- protected ChannelInterceptor interceptors = null;
- /**
- * A list of membership listeners that subscribe to membership announcements
- */
- protected ArrayList<Object> membershipListeners = new ArrayList<Object>();
- /**
- * A list of channel listeners that subscribe to incoming messages
- */
- protected ArrayList<Object> channelListeners = new ArrayList<Object>();
- /**
- * If set to true, the GroupChannel will check to make sure that
- */
- protected boolean optionCheck = false;
- /**
- * Creates a GroupChannel. This constructor will also
- * add the first interceptor in the GroupChannel.<br>
- * The first interceptor is always the channel itself.
- */
- public GroupChannel() {
- addInterceptor(this);
- }
- /**
- * Adds an interceptor to the stack for message processing<br>
- * Interceptors are ordered in the way they are added.<br>
- * <code>channel.addInterceptor(A);</code><br>
- * <code>channel.addInterceptor(C);</code><br>
- * <code>channel.addInterceptor(B);</code><br>
- * Will result in a interceptor stack like this:<br>
- * <code>A -> C -> B</code><br>
- * The complete stack will look like this:<br>
- * <code>Channel -> A -> C -> B -> ChannelCoordinator</code><br>
- * @param interceptor ChannelInterceptorBase
- */
- public void addInterceptor(ChannelInterceptor interceptor) {
- if ( interceptors == null ) {
- interceptors = interceptor;
- interceptors.setNext(coordinator);
- interceptors.setPrevious(null);
- coordinator.setPrevious(interceptors);
- } else {
- ChannelInterceptor last = interceptors;
- while ( last.getNext() != coordinator ) {
- last = last.getNext();
- }
- last.setNext(interceptor);
- interceptor.setNext(coordinator);
- interceptor.setPrevious(last);
- coordinator.setPrevious(interceptor);
- }
- }
- /**
- * Sends a heartbeat through the interceptor stack.<br>
- * Invoke this method from the application on a periodic basis if
- * you have turned off internal heartbeats <code>channel.setHeartbeat(false)</code>
- */
- @Override
- public void heartbeat() {
- super.heartbeat();
- Iterator<Object> i = membershipListeners.iterator();
- while ( i.hasNext() ) {
- Object o = i.next();
- if ( o instanceof Heartbeat ) ((Heartbeat)o).heartbeat();
- }
- i = channelListeners.iterator();
- while ( i.hasNext() ) {
- Object o = i.next();
- if ( o instanceof Heartbeat ) ((Heartbeat)o).heartbeat();
- }
- }
- /**
- * Send a message to the destinations specified
- * @param destination Member[] - destination.length > 1
- * @param msg Serializable - the message to send
- * @param options int - sender options, options can trigger guarantee levels and different interceptors to
- * react to the message see class documentation for the <code>Channel</code> object.<br>
- * @return UniqueId - the unique Id that was assigned to this message
- * @throws ChannelException - if an error occurs processing the message
- * @see org.apache.catalina.tribes.Channel
- */
- public UniqueId send(Member[] destination, Serializable msg, int options) throws ChannelException {
- return send(destination,msg,options,null);
- }
- /**
- *
- * @param destination Member[] - destination.length > 1
- * @param msg Serializable - the message to send
- * @param options int - sender options, options can trigger guarantee levels and different interceptors to
- * react to the message see class documentation for the <code>Channel</code> object.<br>
- * @param handler - callback object for error handling and completion notification, used when a message is
- * sent asynchronously using the <code>Channel.SEND_OPTIONS_ASYNCHRONOUS</code> flag enabled.
- * @return UniqueId - the unique Id that was assigned to this message
- * @throws ChannelException - if an error occurs processing the message
- * @see org.apache.catalina.tribes.Channel
- */
- public UniqueId send(Member[] destination, Serializable msg, int options, ErrorHandler handler) throws ChannelException {
- if ( msg == null ) throw new ChannelException("Cant send a NULL message");
- XByteBuffer buffer = null;
- try {
- if ( destination == null || destination.length == 0) throw new ChannelException("No destination given");
- ChannelData data = new ChannelData(true);//generates a unique Id
- data.setAddress(getLocalMember(false));
- data.setTimestamp(System.currentTimeMillis());
- byte[] b = null;
- if ( msg instanceof ByteMessage ){
- b = ((ByteMessage)msg).getMessage();
- options = options | SEND_OPTIONS_BYTE_MESSAGE;
- } else {
- b = XByteBuffer.serialize(msg);
- options = options & (~SEND_OPTIONS_BYTE_MESSAGE);
- }
- data.setOptions(options);
- //XByteBuffer buffer = new XByteBuffer(b.length+128,false);
- buffer = BufferPool.getBufferPool().getBuffer(b.length+128, false);
- buffer.append(b,0,b.length);
- data.setMessage(buffer);
- InterceptorPayload payload = null;
- if ( handler != null ) {
- payload = new InterceptorPayload();
- payload.setErrorHandler(handler);
- }
- getFirstInterceptor().sendMessage(destination, data, payload);
- if ( Logs.MESSAGES.isTraceEnabled() ) {
- Logs.MESSAGES.trace("GroupChannel - Sent msg:" + new UniqueId(data.getUniqueId()) + " at " +new java.sql.Timestamp(System.currentTimeMillis())+ " to "+Arrays.toNameString(destination));
- Logs.MESSAGES.trace("GroupChannel - Send Message:" + new UniqueId(data.getUniqueId()) + " is " +msg);
- }
- return new UniqueId(data.getUniqueId());
- }catch ( Exception x ) {
- if ( x instanceof ChannelException ) throw (ChannelException)x;
- throw new ChannelException(x);
- } finally {
- if ( buffer != null ) BufferPool.getBufferPool().returnBuffer(buffer);
- }
- }
- /**
- * Callback from the interceptor stack. <br>
- * When a message is received from a remote node, this method will be invoked by
- * the previous interceptor.<br>
- * This method can also be used to send a message to other components within the same application,
- * but its an extreme case, and you're probably better off doing that logic between the applications itself.
- * @param msg ChannelMessage
- */
- @Override
- public void messageReceived(ChannelMessage msg) {
- if ( msg == null ) return;
- try {
- if ( Logs.MESSAGES.isTraceEnabled() ) {
- Logs.MESSAGES.trace("GroupChannel - Received msg:" + new UniqueId(msg.getUniqueId()) + " at " +new java.sql.Timestamp(System.currentTimeMillis())+ " from "+msg.getAddress().getName());
- }
- Serializable fwd = null;
- if ( (msg.getOptions() & SEND_OPTIONS_BYTE_MESSAGE) == SEND_OPTIONS_BYTE_MESSAGE ) {
- fwd = new ByteMessage(msg.getMessage().getBytes());
- } else {
- try {
- fwd = XByteBuffer.deserialize(msg.getMessage().getBytesDirect(), 0, msg.getMessage().getLength());
- }catch (Exception sx) {
- log.error("Unable to deserialize message:"+msg,sx);
- return;
- }
- }
- if ( Logs.MESSAGES.isTraceEnabled() ) {
- Logs.MESSAGES.trace("GroupChannel - Receive Message:" + new UniqueId(msg.getUniqueId()) + " is " +fwd);
- }
- //get the actual member with the correct alive time
- Member source = msg.getAddress();
- boolean rx = false;
- boolean delivered = false;
- for ( int i=0; i<channelListeners.size(); i++ ) {
- ChannelListener channelListener = (ChannelListener)channelListeners.get(i);
- if (channelListener != null && channelListener.accept(fwd, source)) {
- channelListener.messageReceived(fwd, source);
- delivered = true;
- //if the message was accepted by an RPC channel, that channel
- //is responsible for returning the reply, otherwise we send an absence reply
- if ( channelListener instanceof RpcChannel ) rx = true;
- }
- }//for
- if ((!rx) && (fwd instanceof RpcMessage)) {
- //if we have a message that requires a response,
- //but none was given, send back an immediate one
- sendNoRpcChannelReply((RpcMessage)fwd,source);
- }
- if ( Logs.MESSAGES.isTraceEnabled() ) {
- Logs.MESSAGES.trace("GroupChannel delivered["+delivered+"] id:"+new UniqueId(msg.getUniqueId()));
- }
- } catch ( Exception x ) {
- //this could be the channel listener throwing an exception, we should log it
- //as a warning.
- if ( log.isWarnEnabled() ) log.warn("Error receiving message:",x);
- throw new RemoteProcessException("Exception:"+x.getMessage(),x);
- }
- }
- /**
- * Sends a <code>NoRpcChannelReply</code> message to a member<br>
- * This method gets invoked by the channel if a RPC message comes in
- * and no channel listener accepts the message. This avoids timeout
- * @param msg RpcMessage
- * @param destination Member - the destination for the reply
- */
- protected void sendNoRpcChannelReply(RpcMessage msg, Member destination) {
- try {
- //avoid circular loop
- if ( msg instanceof RpcMessage.NoRpcChannelReply) return;
- RpcMessage.NoRpcChannelReply reply = new RpcMessage.NoRpcChannelReply(msg.rpcId,msg.uuid);
- send(new Member[]{destination},reply,Channel.SEND_OPTIONS_ASYNCHRONOUS);
- } catch ( Exception x ) {
- log.error("Unable to find rpc channel, failed to send NoRpcChannelReply.",x);
- }
- }
- /**
- * memberAdded gets invoked by the interceptor below the channel
- * and the channel will broadcast it to the membership listeners
- * @param member Member - the new member
- */
- @Override
- public void memberAdded(Member member) {
- //notify upwards
- for (int i=0; i<membershipListeners.size(); i++ ) {
- MembershipListener membershipListener = (MembershipListener)membershipListeners.get(i);
- if (membershipListener != null) membershipListener.memberAdded(member);
- }
- }
- /**
- * memberDisappeared gets invoked by the interceptor below the channel
- * and the channel will broadcast it to the membership listeners
- * @param member Member - the member that left or crashed
- */
- @Override
- public void memberDisappeared(Member member) {
- //notify upwards
- for (int i=0; i<membershipListeners.size(); i++ ) {
- MembershipListener membershipListener = (MembershipListener)membershipListeners.get(i);
- if (membershipListener != null) membershipListener.memberDisappeared(member);
- }
- }
- /**
- * Sets up the default implementation interceptor stack
- * if no interceptors have been added
- * @throws ChannelException
- */
- protected synchronized void setupDefaultStack() throws ChannelException {
- if ( getFirstInterceptor() != null &&
- ((getFirstInterceptor().getNext() instanceof ChannelCoordinator))) {
- ChannelInterceptor interceptor = null;
- Class<?> clazz = null;
- try {
- clazz = Class.forName("org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor",
- true,GroupChannel.class.getClassLoader());
- clazz.newInstance();
- } catch ( Throwable x ) {
- clazz = MessageDispatchInterceptor.class;
- }//catch
- try {
- interceptor = (ChannelInterceptor) clazz.newInstance();
- } catch (Exception x) {
- throw new ChannelException("Unable to add MessageDispatchInterceptor to interceptor chain.",x);
- }
- this.addInterceptor(interceptor);
- }
- }
- /**
- * Validates the option flags that each interceptor is using and reports
- * an error if two interceptor share the same flag.
- * @throws ChannelException
- */
- protected void checkOptionFlags() throws ChannelException {
- StringBuilder conflicts = new StringBuilder();
- ChannelInterceptor first = interceptors;
- while ( first != null ) {
- int flag = first.getOptionFlag();
- if ( flag != 0 ) {
- ChannelInterceptor next = first.getNext();
- while ( next != null ) {
- int nflag = next.getOptionFlag();
- if (nflag!=0 && (((flag & nflag) == flag ) || ((flag & nflag) == nflag)) ) {
- conflicts.append("[");
- conflicts.append(first.getClass().getName());
- conflicts.append(":");
- conflicts.append(flag);
- conflicts.append(" == ");
- conflicts.append(next.getClass().getName());
- conflicts.append(":");
- conflicts.append(nflag);
- conflicts.append("] ");
- }//end if
- next = next.getNext();
- }//while
- }//end if
- first = first.getNext();
- }//while
- if ( conflicts.length() > 0 ) throw new ChannelException("Interceptor option flag conflict: "+conflicts.toString());
- }
- /**
- * Starts the channel
- * @param svc int - what service to start
- * @throws ChannelException
- * @see org.apache.catalina.tribes.Channel#start(int)
- */
- @Override
- public synchronized void start(int svc) throws ChannelException {
- setupDefaultStack();
- if (optionCheck) checkOptionFlags();
- super.start(svc);
- if ( hbthread == null && heartbeat ) {
- hbthread = new HeartbeatThread(this,heartbeatSleeptime);
- hbthread.start();
- }
- }
- /**
- * Stops the channel
- * @param svc int
- * @throws ChannelException
- * @see org.apache.catalina.tribes.Channel#stop(int)
- */
- @Override
- public synchronized void stop(int svc) throws ChannelException {
- if (hbthread != null) {
- hbthread.stopHeartbeat();
- hbthread = null;
- }
- super.stop(svc);
- }
- /**
- * Returns the first interceptor of the stack. Useful for traversal.
- * @return ChannelInterceptor
- */
- public ChannelInterceptor getFirstInterceptor() {
- if (interceptors != null) return interceptors;
- else return coordinator;
- }
- /**
- * Returns the channel receiver component
- * @return ChannelReceiver
- */
- public ChannelReceiver getChannelReceiver() {
- return coordinator.getClusterReceiver();
- }
- /**
- * Returns the channel sender component
- * @return ChannelSender
- */
- public ChannelSender getChannelSender() {
- return coordinator.getClusterSender();
- }
- /**
- * Returns the membership service component
- * @return MembershipService
- */
- public MembershipService getMembershipService() {
- return coordinator.getMembershipService();
- }
- /**
- * Sets the channel receiver component
- * @param clusterReceiver ChannelReceiver
- */
- public void setChannelReceiver(ChannelReceiver clusterReceiver) {
- coordinator.setClusterReceiver(clusterReceiver);
- }
- /**
- * Sets the channel sender component
- * @param clusterSender ChannelSender
- */
- public void setChannelSender(ChannelSender clusterSender) {
- coordinator.setClusterSender(clusterSender);
- }
- /**
- * Sets the membership component
- * @param membershipService MembershipService
- */
- public void setMembershipService(MembershipService membershipService) {
- coordinator.setMembershipService(membershipService);
- }
- /**
- * Adds a membership listener to the channel.<br>
- * Membership listeners are uniquely identified using the equals(Object) method
- * @param membershipListener MembershipListener
- */
- public void addMembershipListener(MembershipListener membershipListener) {
- if (!this.membershipListeners.contains(membershipListener) )
- this.membershipListeners.add(membershipListener);
- }
- /**
- * Removes a membership listener from the channel.<br>
- * Membership listeners are uniquely identified using the equals(Object) method
- * @param membershipListener MembershipListener
- */
- public void removeMembershipListener(MembershipListener membershipListener) {
- membershipListeners.remove(membershipListener);
- }
- /**
- * Adds a channel listener to the channel.<br>
- * Channel listeners are uniquely identified using the equals(Object) method
- * @param channelListener ChannelListener
- */
- public void addChannelListener(ChannelListener channelListener) {
- if (!this.channelListeners.contains(channelListener) ) {
- this.channelListeners.add(channelListener);
- } else {
- throw new IllegalArgumentException("Listener already exists:"+channelListener+"["+channelListener.getClass().getName()+"]");
- }
- }
- /**
- *
- * Removes a channel listener from the channel.<br>
- * Channel listeners are uniquely identified using the equals(Object) method
- * @param channelListener ChannelListener
- */
- public void removeChannelListener(ChannelListener channelListener) {
- channelListeners.remove(channelListener);
- }
- /**
- * Returns an iterator of all the interceptors in this stack
- * @return Iterator
- */
- public Iterator<ChannelInterceptor> getInterceptors() {
- return new InterceptorIterator(this.getNext(),this.coordinator);
- }
- /**
- * Enables/disables the option check<br>
- * Setting this to true, will make the GroupChannel perform a conflict check
- * on the interceptors. If two interceptors are using the same option flag
- * and throw an error upon start.
- * @param optionCheck boolean
- */
- public void setOptionCheck(boolean optionCheck) {
- this.optionCheck = optionCheck;
- }
- /**
- * Configure local heartbeat sleep time<br>
- * Only used when <code>getHeartbeat()==true</code>
- * @param heartbeatSleeptime long - time in milliseconds to sleep between heartbeats
- */
- public void setHeartbeatSleeptime(long heartbeatSleeptime) {
- this.heartbeatSleeptime = heartbeatSleeptime;
- }
- /**
- * Enables or disables local heartbeat.
- * if <code>setHeartbeat(true)</code> is invoked then the channel will start an internal
- * thread to invoke <code>Channel.heartbeat()</code> every <code>getHeartbeatSleeptime</code> milliseconds
- * @param heartbeat boolean
- */
- public void setHeartbeat(boolean heartbeat) {
- this.heartbeat = heartbeat;
- }
- /**
- * @see #setOptionCheck(boolean)
- * @return boolean
- */
- public boolean getOptionCheck() {
- return optionCheck;
- }
- /**
- * @see #setHeartbeat(boolean)
- * @return boolean
- */
- public boolean getHeartbeat() {
- return heartbeat;
- }
- /**
- * Returns the sleep time in milliseconds that the internal heartbeat will
- * sleep in between invocations of <code>Channel.heartbeat()</code>
- * @return long
- */
- public long getHeartbeatSleeptime() {
- return heartbeatSleeptime;
- }
- /**
- *
- * <p>Title: Interceptor Iterator</p>
- *
- * <p>Description: An iterator to loop through the interceptors in a channel</p>
- *
- * @version 1.0
- */
- public static class InterceptorIterator implements Iterator<ChannelInterceptor> {
- private ChannelInterceptor end;
- private ChannelInterceptor start;
- public InterceptorIterator(ChannelInterceptor start, ChannelInterceptor end) {
- this.end = end;
- this.start = start;
- }
- public boolean hasNext() {
- return start!=null && start != end;
- }
- public ChannelInterceptor next() {
- ChannelInterceptor result = null;
- if ( hasNext() ) {
- result = start;
- start = start.getNext();
- }
- return result;
- }
- public void remove() {
- //empty operation
- }
- }
- /**
- *
- * <p>Title: Internal heartbeat thread</p>
- *
- * <p>Description: if <code>Channel.getHeartbeat()==true</code> then a thread of this class
- * is created</p>
- *
- * @version 1.0
- */
- public static class HeartbeatThread extends Thread {
- private static final Log log = LogFactory.getLog(HeartbeatThread.class);
- protected static int counter = 1;
- protected static synchronized int inc() {
- return counter++;
- }
- protected volatile boolean doRun = true;
- protected GroupChannel channel;
- protected long sleepTime;
- public HeartbeatThread(GroupChannel channel, long sleepTime) {
- super();
- this.setPriority(MIN_PRIORITY);
- setName("GroupChannel-Heartbeat-"+inc());
- setDaemon(true);
- this.channel = channel;
- this.sleepTime = sleepTime;
- }
- public void stopHeartbeat() {
- doRun = false;
- interrupt();
- }
- @Override
- public void run() {
- while (doRun) {
- try {
- Thread.sleep(sleepTime);
- channel.heartbeat();
- } catch ( InterruptedException x ) {
- interrupted();
- } catch ( Exception x ) {
- log.error("Unable to send heartbeat through Tribes interceptor stack. Will try to sleep again.",x);
- }//catch
- }//while
- }//run
- }//HeartbeatThread
- }