/*
* Copyright 1999,2004 The Apache Software Foundation.
*
* Licensed 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.cluster.session;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.Iterator;
import javax.servlet.ServletContext;
import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Globals;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.Loader;
import org.apache.catalina.Session;
import org.apache.catalina.util.CustomObjectInputStream;
import org.apache.catalina.util.LifecycleSupport;
import org.apache.catalina.session.ManagerBase;
import org.apache.catalina.cluster.ClusterManager;
import org.apache.catalina.cluster.SessionMessage;
import org.apache.catalina.cluster.Member;
import org.apache.catalina.cluster.CatalinaCluster;
/**
* The DeltaManager manages replicated sessions by only
* replicating the deltas in data. For applications written
* to handle this, the DeltaManager is the optimal way of replicating data.
*
* This code is almost identical to StandardManager with a difference in
* how it persists sessions and some modifications to it.
*
* <b>IMPLEMENTATION NOTE</b>: Correct behavior of session storing and
* reloading depends upon external calls to the <code>start()</code> and
* <code>stop()</code> methods of this class at the correct times.
*
* @author Filip Hanik
* @author Craig R. McClanahan
* @author Jean-Francois Arcand
* @version $Revision: 1.26 $ $Date: 2004/05/29 02:43:58 $
*/
public class DeltaManager
extends ManagerBase
implements Lifecycle, PropertyChangeListener, ClusterManager {
// ---------------------------------------------------- Security Classes
public static org.apache.commons.logging.Log log =
org.apache.commons.logging.LogFactory.getLog( DeltaManager.class );
// ----------------------------------------------------- Instance Variables
/**
* The descriptive information about this implementation.
*/
private static final String info = "DeltaManager/1.0";
/**
* The lifecycle event support for this component.
*/
protected LifecycleSupport lifecycle = new LifecycleSupport(this);
/**
* The maximum number of active Sessions allowed, or -1 for no limit.
*/
private int maxActiveSessions = -1;
/**
* The descriptive name of this Manager implementation (for logging).
*/
protected static String managerName = "DeltaManager";
protected String name = null;
/**
* Path name of the disk file in which active sessions are saved
* when we stop, and from which these sessions are loaded when we start.
* A <code>null</code> value indicates that no persistence is desired.
* If this pathname is relative, it will be resolved against the
* temporary working directory provided by our context, available via
* the <code>javax.servlet.context.tempdir</code> context attribute.
*/
private String pathname = "SESSIONS.ser";
/**
* Has this component been started yet?
*/
private boolean started = false;
int rejectedSessions=0;
int expiredSessions=0;
long processingTime=0;
private CatalinaCluster cluster = null;
private boolean stateTransferred;
private boolean useDirtyFlag;
private boolean expireSessionsOnShutdown;
private boolean printToScreen;
// ------------------------------------------------------------- Constructor
public DeltaManager() {
super();
}
// ------------------------------------------------------------- Properties
/**
* Set the Container with which this Manager has been associated. If
* it is a Context (the usual case), listen for changes to the session
* timeout property.
*
* @param container The associated Container
*/
public void setContainer(Container container) {
// De-register from the old Container (if any)
if ((this.container != null) && (this.container instanceof Context))
((Context) this.container).removePropertyChangeListener(this);
// Default processing provided by our superclass
super.setContainer(container);
// Register with the new Container (if any)
if ((this.container != null) && (this.container instanceof Context)) {
setMaxInactiveInterval
( ((Context) this.container).getSessionTimeout()*60 );
((Context) this.container).addPropertyChangeListener(this);
}
}
/**
* Return descriptive information about this Manager implementation and
* the corresponding version number, in the format
* <code><description>/<version></code>.
*/
public String getInfo() {
return (this.info);
}
/**
* Return the maximum number of active Sessions allowed, or -1 for
* no limit.
*/
public int getMaxActiveSessions() {
return (this.maxActiveSessions);
}
/** Number of session creations that failed due to maxActiveSessions
*
* @return The count
*/
public int getRejectedSessions() {
return rejectedSessions;
}
public void setRejectedSessions(int rejectedSessions) {
this.rejectedSessions = rejectedSessions;
}
/** Number of sessions that expired.
*
* @return The count
*/
public int getExpiredSessions() {
return expiredSessions;
}
public void setExpiredSessions(int expiredSessions) {
this.expiredSessions = expiredSessions;
}
public long getProcessingTime() {
return processingTime;
}
public void setProcessingTime(long processingTime) {
this.processingTime = processingTime;
}
/**
* Set the maximum number of actives Sessions allowed, or -1 for
* no limit.
*
* @param max The new maximum number of sessions
*/
public void setMaxActiveSessions(int max) {
int oldMaxActiveSessions = this.maxActiveSessions;
this.maxActiveSessions = max;
support.firePropertyChange("maxActiveSessions",
new Integer(oldMaxActiveSessions),
new Integer(this.maxActiveSessions));
}
/**
* Return the descriptive short name of this Manager implementation.
*/
public String getName() {
return (name);
}
/**
* Return the session persistence pathname, if any.
*/
public String getPathname() {
return (this.pathname);
}
/**
* Set the session persistence pathname to the specified value. If no
* persistence support is desired, set the pathname to <code>null</code>.
*
* @param pathname New session persistence pathname
*/
public void setPathname(String pathname) {
String oldPathname = this.pathname;
this.pathname = pathname;
support.firePropertyChange("pathname", oldPathname, this.pathname);
}
// --------------------------------------------------------- Public Methods
/**
* Construct and return a new session object, based on the default
* settings specified by this Manager's properties. The session
* id will be assigned by this method, and available via the getId()
* method of the returned session. If a new session cannot be created
* for any reason, return <code>null</code>.
*
* @exception IllegalStateException if a new session cannot be
* instantiated for any reason
*
* Construct and return a new session object, based on the default
* settings specified by this Manager's properties. The session
* id will be assigned by this method, and available via the getId()
* method of the returned session. If a new session cannot be created
* for any reason, return <code>null</code>.
*
* @exception IllegalStateException if a new session cannot be
* instantiated for any reason
*/
public Session createSession() {
return createSession(true);
}
public Session createSession(boolean distribute) {
if ((maxActiveSessions >= 0) &&
(sessions.size() >= maxActiveSessions)) {
rejectedSessions++;
throw new IllegalStateException
(sm.getString("standardManager.createSession.ise"));
}
// Recycle or create a Session instance
DeltaSession session = getNewDeltaSession();
String sessionId = generateSessionId();
String jvmRoute = getJvmRoute();
// @todo Move appending of jvmRoute generateSessionId()???
if (jvmRoute != null) {
sessionId += '.' + jvmRoute;
}
synchronized (sessions) {
while (sessions.get(sessionId) != null) { // Guarantee uniqueness
duplicates++;
sessionId = generateSessionId();
// @todo Move appending of jvmRoute generateSessionId()???
if (jvmRoute != null) {
sessionId += '.' + jvmRoute;
}
}
}
session.setNew(true);
session.setValid(true);
session.setCreationTime(System.currentTimeMillis());
session.setMaxInactiveInterval(this.maxInactiveInterval);
session.setId(sessionId);
session.resetDeltaRequest();
// Initialize the properties of the new session and return it
sessionCounter++;
if ( distribute ) {
SessionMessage msg = new SessionMessageImpl(
getName(),
SessionMessage.EVT_SESSION_CREATED,
null,
sessionId,
sessionId+System.currentTimeMillis());
cluster.send(msg);
session.resetDeltaRequest();
}
log.debug("Created a DeltaSession with Id["+session.getId()+"] Total count="+sessions.size());
return (session);
}
/**
* Get new session class to be used in the doLoad() method.
*/
protected DeltaSession getNewDeltaSession() {
return new DeltaSession(this);
}
private DeltaRequest loadDeltaRequest(DeltaSession session, byte[] data) throws
ClassNotFoundException, IOException {
ByteArrayInputStream fis = null;
ReplicationStream ois = null;
Loader loader = null;
ClassLoader classLoader = null;
//fix to be able to run the DeltaManager
//stand alone without a container.
//use the Threads context class loader
if ( container != null )
loader = container.getLoader();
if ( loader != null )
classLoader = loader.getClassLoader();
else
classLoader = Thread.currentThread().getContextClassLoader();
//end fix
fis = new ByteArrayInputStream(data);
ois = new ReplicationStream(fis,classLoader);
session.getDeltaRequest().readExternal(ois);
ois.close();
return session.getDeltaRequest();
}
private byte[] unloadDeltaRequest(DeltaRequest deltaRequest) throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bos);
deltaRequest.writeExternal(oos);
oos.flush();
oos.close();
return bos.toByteArray();
}
/**
* Load any currently active sessions that were previously unloaded
* to the appropriate persistence mechanism, if any. If persistence is not
* supported, this method returns without doing anything.
*
* @exception ClassNotFoundException if a serialized class cannot be
* found during the reload
* @exception IOException if an input/output error occurs
*/
private void doLoad(byte[] data) throws ClassNotFoundException, IOException {
// Initialize our internal data structures
//sessions.clear(); //should not do this
// Open an input stream to the specified pathname, if any
ByteArrayInputStream fis = null;
ObjectInputStream ois = null;
Loader loader = null;
ClassLoader classLoader = null;
try {
fis = new ByteArrayInputStream(data);
BufferedInputStream bis = new BufferedInputStream(fis);
if (container != null)
loader = container.getLoader();
if (loader != null)
classLoader = loader.getClassLoader();
if (classLoader != null) {
ois = new CustomObjectInputStream(bis, classLoader);
} else {
ois = new ObjectInputStream(bis);
}
} catch (IOException e) {
log.error(sm.getString("standardManager.loading.ioe", e), e);
if (ois != null) {
try {
ois.close();
} catch (IOException f) {
;
}
ois = null;
}
throw e;
}
// Load the previously unloaded active sessions
synchronized (sessions) {
try {
Integer count = (Integer) ois.readObject();
int n = count.intValue();
for (int i = 0; i < n; i++) {
DeltaSession session = getNewDeltaSession();
session.readObjectData(ois);
session.setManager(this);
session.setValid(true);
session.setPrimarySession(false);
//in case the nodes in the cluster are out of
//time synch, this will make sure that we have the
//correct timestamp, isValid returns true, cause accessCount=1
session.access();
//make sure that the session gets ready to expire if needed
session.setAccessCount(0);
sessions.put(session.getId(), session);
}
} catch (ClassNotFoundException e) {
log.error(sm.getString("standardManager.loading.cnfe", e), e);
if (ois != null) {
try {
ois.close();
} catch (IOException f) {
;
}
ois = null;
}
throw e;
} catch (IOException e) {
log.error(sm.getString("standardManager.loading.ioe", e), e);
if (ois != null) {
try {
ois.close();
} catch (IOException f) {
;
}
ois = null;
}
throw e;
} finally {
// Close the input stream
try {
if (ois != null)
ois.close();
} catch (IOException f) {
// ignored
}
}
}
}
/**
* Save any currently active sessions in the appropriate persistence
* mechanism, if any. If persistence is not supported, this method
* returns without doing anything.
*
* @exception IOException if an input/output error occurs
*/
private byte[] doUnload() throws IOException {
// Open an output stream to the specified pathname, if any
ByteArrayOutputStream fos = null;
ObjectOutputStream oos = null;
try {
fos = new ByteArrayOutputStream();
oos = new ObjectOutputStream(new BufferedOutputStream(fos));
} catch (IOException e) {
log.error(sm.getString("standardManager.unloading.ioe", e), e);
if (oos != null) {
try {
oos.close();
} catch (IOException f) {
;
}
oos = null;
}
throw e;
}
// Write the number of active sessions, followed by the details
ArrayList list = new ArrayList();
synchronized (sessions) {
try {
oos.writeObject(new Integer(sessions.size()));
Iterator elements = sessions.values().iterator();
while (elements.hasNext()) {
DeltaSession session =
(DeltaSession) elements.next();
list.add(session);
session.writeObjectData(oos);
}
oos.flush();
oos.close();
oos = null;
} catch (IOException e) {
log.error(sm.getString("standardManager.unloading.ioe", e), e);
if (oos != null) {
try {
oos.close();
} catch (IOException f) {
;
}
oos = null;
}
throw e;
}
}
// Flush and close the output stream
return fos.toByteArray();
}
// ------------------------------------------------------ Lifecycle Methods
/**
* Add a lifecycle event listener to this component.
*
* @param listener The listener to add
*/
public void addLifecycleListener(LifecycleListener listener) {
lifecycle.addLifecycleListener(listener);
}
/**
* Get the lifecycle listeners associated with this lifecycle. If this
* Lifecycle has no listeners registered, a zero-length array is returned.
*/
public LifecycleListener[] findLifecycleListeners() {
return lifecycle.findLifecycleListeners();
}
/**
* Remove a lifecycle event listener from this component.
*
* @param listener The listener to remove
*/
public void removeLifecycleListener(LifecycleListener listener) {
lifecycle.removeLifecycleListener(listener);
}
/**
* Prepare for the beginning of active use of the public methods of this
* component. This method should be called after <code>configure()</code>,
* and before any of the public methods of the component are utilized.
*
* @exception LifecycleException if this component detects a fatal error
* that prevents this component from being used
*/
public void start() throws LifecycleException {
if( ! initialized )
init();
// Validate and update our current component state
if (started) {
return;
}
started = true;
lifecycle.fireLifecycleEvent(START_EVENT, null);
// Force initialization of the random number generator
String dummy = generateSessionId();
// Load unloaded sessions, if any
try {
//the channel is already running
log.info("Starting clustering manager...:"+getName());
if ( cluster == null ) {
log.error("Starting... no cluster associated with this context:"+getName());
return;
}
if (cluster.getMembers().length > 0) {
Member mbr = cluster.getMembers()[0];
SessionMessage msg =
new SessionMessageImpl(this.getName(),
SessionMessage.EVT_GET_ALL_SESSIONS,
null,
"GET-ALL",
"GET-ALL-"+getName());
//just to make sure the other server has the context started
// long timetowait = 20000-mbr.getMemberAliveTime();
// if ( timetowait > 0 ) {
// log.info("The other server has not been around more than 20 seconds, will sleep for "+timetowait+" ms. in order to let it startup");
// try { Thread.currentThread().sleep(timetowait); } catch ( Exception x ) {}
// }//end if
//request session state
cluster.send(msg, mbr);
log.warn("Manager["+getName()+"], requesting session state from "+mbr+
". This operation will timeout if no session state has been received within "+
"60 seconds");
long reqStart = System.currentTimeMillis();
long reqNow = 0;
boolean isTimeout=false;
do {
try {
Thread.currentThread().sleep(100);
}catch ( Exception sleep) {}
reqNow = System.currentTimeMillis();
isTimeout=((reqNow-reqStart)>(1000*60));
} while ( (!getStateTransferred()) && (!isTimeout));
if ( isTimeout || (!getStateTransferred()) ) {
log.error("Manager["+getName()+"], No session state received, timing out.");
}else {
log.info("Manager["+getName()+"], session state received in "+(reqNow-reqStart)+" ms.");
}
} else {
log.info("Manager["+getName()+"], skipping state transfer. No members active in cluster group.");
}//end if
} catch (Throwable t) {
log.error(sm.getString("standardManager.managerLoad"), t);
}
}
/**
* Gracefully terminate the active use of the public methods of this
* component. This method should be the last one called on a given
* instance of this component.
*
* @exception LifecycleException if this component detects a fatal error
* that needs to be reported
*/
public void stop() throws LifecycleException {
if (log.isDebugEnabled())
log.debug("Stopping");
// Validate and update our current component state
if (!started)
throw new LifecycleException
(sm.getString("standardManager.notStarted"));
lifecycle.fireLifecycleEvent(STOP_EVENT, null);
started = false;
// Expire all active sessions
if ( this.getExpireSessionsOnShutdown() ) {
log.info("Expiring sessions upon shutdown");
Session sessions[] = findSessions();
for (int i = 0; i < sessions.length; i++) {
DeltaSession session = (DeltaSession) sessions[i];
if (!session.isValid())
continue;
try {
session.expire();
}
catch (Throwable t) {
;
} //catch
} //for
}//end if
// Require a new random number generator if we are restarted
this.random = null;
if( initialized ) {
destroy();
}
}
// ----------------------------------------- PropertyChangeListener Methods
/**
* Process property change events from our associated Context.
*
* @param event The property change event that has occurred
*/
public void propertyChange(PropertyChangeEvent event) {
// Validate the source of this event
if (!(event.getSource() instanceof Context))
return;
Context context = (Context) event.getSource();
// Process a relevant property change
if (event.getPropertyName().equals("sessionTimeout")) {
try {
setMaxInactiveInterval
( ((Integer) event.getNewValue()).intValue()*60 );
} catch (NumberFormatException e) {
log.error(sm.getString("standardManager.sessionTimeout",
event.getNewValue().toString()));
}
}
}
// -------------------------------------------------------- Replication Methods
/**
* A message was received from another node, this
* is the callback method to implement if you are interested in
* receiving replication messages.
* @param msg - the message received.
*/
public void messageDataReceived(SessionMessage msg) {
messageReceived(msg, msg.getAddress()!=null?(Member)msg.getAddress():null);
}
/**
* When the request has been completed, the replication valve
* will notify the manager, and the manager will decide whether
* any replication is needed or not.
* If there is a need for replication, the manager will
* create a session message and that will be replicated.
* The cluster determines where it gets sent.
* @param sessionId - the sessionId that just completed.
* @return a SessionMessage to be sent,
*/
public SessionMessage requestCompleted(String sessionId) {
try {
DeltaSession session = (DeltaSession) findSession(sessionId);
DeltaRequest deltaRequest = session.getDeltaRequest();
SessionMessage msg = null;
if (deltaRequest.getSize() > 0) {
byte[] data = unloadDeltaRequest(deltaRequest);
msg = new SessionMessageImpl(name, SessionMessage.EVT_SESSION_DELTA,
data, sessionId,
sessionId+System.currentTimeMillis());
session.resetDeltaRequest();
} else if ( !session.isPrimarySession() ) {
msg = new SessionMessageImpl(getName(),
SessionMessage.EVT_SESSION_ACCESSED,
null,
sessionId,
sessionId+System.currentTimeMillis());
}
session.setPrimarySession(true);
//check to see if we need to send out an access message
if ( (msg == null) ) {
long replDelta = System.currentTimeMillis() - session.getLastTimeReplicated();
if ( replDelta > (getMaxInactiveInterval()*1000) ) {
msg = new SessionMessageImpl(getName(),
SessionMessage.EVT_SESSION_ACCESSED,
null,
sessionId,
sessionId+System.currentTimeMillis());
}
}
//update last replicated time
if ( msg != null ) session.setLastTimeReplicated(System.currentTimeMillis());
return msg;
}
catch (IOException x) {
log.error("Unable to serialize delta request", x);
return null;
}
}
protected void sessionExpired(String id) {
SessionMessage msg = new SessionMessageImpl(getName(),
SessionMessage.EVT_SESSION_EXPIRED,
null,
id,
id+"-EXPIRED-MSG");
cluster.send(msg);
}
/**
* When the manager expires session not tied to a request.
* The cluster will periodically ask for a list of sessions
* that should expire and that should be sent across the wire.
* @return
*/
public String[] getInvalidatedSessions() {
return new String[0];
}
/**
* This method is called by the received thread when a SessionMessage has
* been received from one of the other nodes in the cluster.
* @param msg - the message received
* @param sender - the sender of the message, this is used if we receive a
* EVT_GET_ALL_SESSION message, so that we only reply to
* the requesting node
*/
protected void messageReceived(SessionMessage msg, Member sender) {
try {
log.debug("Manager ("+name+") Received SessionMessage of type=" + msg.getEventTypeString()+" from "+sender);
switch (msg.getEventType()) {
case SessionMessage.EVT_GET_ALL_SESSIONS: {
//get a list of all the session from this manager
log.debug("Manager ("+name+") unloading sessions");
byte[] data = doUnload();
log.debug("Manager ("+name+") unloading sessions complete");
SessionMessage newmsg = new SessionMessageImpl(name,
SessionMessage.EVT_ALL_SESSION_DATA,
data, "SESSION-STATE","SESSION-STATE-"+getName());
cluster.send(newmsg, sender);
break;
}
case SessionMessage.EVT_ALL_SESSION_DATA: {
log.debug("Manager ("+name+") received session state data.");
byte[] data = msg.getSession();
doLoad(data);
log.debug("Manager ("+name+") state deserialized.");
stateTransferred = true;
break;
}
case SessionMessage.EVT_SESSION_CREATED: {
DeltaSession session = (DeltaSession)createSession(false);
session.setId(msg.getSessionID());
session.setNew(false);
session.setPrimarySession(false);
session.resetDeltaRequest();
break;
}
case SessionMessage.EVT_SESSION_EXPIRED: {
DeltaSession session = (DeltaSession)findSession(msg.getSessionID());
if (session != null) {
session.expire(true,false);
} //end if
break;
}
case SessionMessage.EVT_SESSION_ACCESSED: {
DeltaSession session = (DeltaSession)findSession(msg.getSessionID());
if (session != null) {
session.access();
session.setPrimarySession(false);
session.endAccess();
}
break;
}
case SessionMessage.EVT_SESSION_DELTA : {
byte[] delta = msg.getSession();
DeltaSession session = (DeltaSession)findSession(msg.getSessionID());
if (session != null) {
DeltaRequest dreq = loadDeltaRequest(session, delta);
dreq.execute(session);
session.setPrimarySession(false);
}
break;
}
default: {
//we didn't recognize the message type, do nothing
break;
}
} //switch
}
catch (Exception x) {
log.error("Unable to receive message through TCP channel", x);
}
}
// -------------------------------------------------------- Private Methods
public void backgroundProcess() {
log.debug("DeltaManager.backgroundProcess invoked at "+System.currentTimeMillis());
processExpires();
}
/**
* Invalidate all sessions that have expired.
*/
public void processExpires() {
long timeNow = System.currentTimeMillis();
Session sessions[] = findSessions();
for (int i = 0; i < sessions.length; i++) {
DeltaSession session = (DeltaSession) sessions[i];
if (!session.isValid()) {
try {
expiredSessions++;
} catch (Throwable t) {
log.error(sm.getString
("standardManager.expireException"), t);
}
}
}
long timeEnd = System.currentTimeMillis();
processingTime += ( timeEnd - timeNow );
}
public boolean getStateTransferred() {
return stateTransferred;
}
public void setStateTransferred(boolean stateTransferred) {
this.stateTransferred = stateTransferred;
}
public CatalinaCluster getCluster() {
return cluster;
}
public void setCluster(CatalinaCluster cluster) {
this.cluster = cluster;
}
public void load() {
}
public void unload() {
}
public boolean getUseDirtyFlag() {
return useDirtyFlag;
}
public void setUseDirtyFlag(boolean useDirtyFlag) {
this.useDirtyFlag = useDirtyFlag;
}
public boolean getExpireSessionsOnShutdown() {
return expireSessionsOnShutdown;
}
public void setExpireSessionsOnShutdown(boolean expireSessionsOnShutdown) {
this.expireSessionsOnShutdown = expireSessionsOnShutdown;
}
public boolean getPrintToScreen() {
return printToScreen;
}
public void setPrintToScreen(boolean printToScreen) {
this.printToScreen = printToScreen;
}
public void setName(String name) {
this.name = name;
}
}