/*
* 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.ha.session;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Engine;
import org.apache.catalina.Globals;
import org.apache.catalina.Host;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.Manager;
import org.apache.catalina.Session;
import org.apache.catalina.ha.CatalinaCluster;
import org.apache.catalina.ha.ClusterManager;
import org.apache.catalina.ha.ClusterMessage;
import org.apache.catalina.ha.ClusterValve;
import org.apache.catalina.ha.session.DeltaSession;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.session.ManagerBase;
import org.apache.catalina.session.PersistentManager;
import org.apache.catalina.util.LifecycleSupport;
import org.apache.catalina.util.StringManager;
import org.apache.catalina.valves.ValveBase;
/**
* Valve to handle Tomcat jvmRoute takeover using mod_jk module after node
* failure. After a node crashes, subsequent requests go to other cluster nodes.
* That incurs a drop in performance. When this Valve is enabled on a backup
* node and sees a request, which was intended for another (thus failed) node,
* it will rewrite the cookie jsessionid information to use the route to this
* backup cluster node, that answered the request. After the response is
* delivered to the client, all subsequent client requests will go directly to
* the backup node. The change of sessionid is also sent to all other cluster
* nodes. After all that, the session stickyness will work directly to the
* backup node and the traffic will not go back to the failed node after it is
* restarted!
*
* <p>
* For this valve to function correctly, so that all nodes of the cluster
* receive the sessionid change notifications that it generates, the following
* ClusterListener MUST be configured at all nodes of the cluster:
* {@link org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener
* JvmRouteSessionIDBinderListener} since Tomcat 5.5.10, and both
* JvmRouteSessionIDBinderListener and JvmRouteSessionIDBinderLifecycleListener
* for earlier versions of Tomcat.
*
* <p>
* Add this Valve to your host definition at conf/server.xml .
*
* Since 5.5.10 as direct cluster valve:<br/>
*
* <pre>
* <Cluster>
* <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve" />
* </Cluster>
* </pre>
*
* <br />
* Before 5.5.10 as Host element:<br/>
*
* <pre>
* <Host>
* <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve" />
* </Host>
* </pre>
*
* <em>A Trick:</em><br/>
* You can enable this mod_jk turnover mode via JMX before you drop a node to
* all backup nodes! Set enable true on all JvmRouteBinderValve backups, disable
* worker at mod_jk and then drop node and restart it! Then enable mod_jk worker
* and disable JvmRouteBinderValves again. This use case means that only
* requested sessions are migrated.
*
* @author Peter Rossbach
*
*/
public class JvmRouteBinderValve extends ValveBase implements ClusterValve, Lifecycle {
/*--Static Variables----------------------------------------*/
public static org.apache.juli.logging.Log log = org.apache.juli.logging.LogFactory
.getLog(JvmRouteBinderValve.class);
/**
* The descriptive information about this implementation.
*/
protected static final String info = "org.apache.catalina.ha.session.JvmRouteBinderValve/1.2";
/*--Instance Variables--------------------------------------*/
/**
* the cluster
*/
protected CatalinaCluster cluster;
/**
* The string manager for this package.
*/
protected StringManager sm = StringManager.getManager(Constants.Package);
/**
* Has this component been started yet?
*/
protected boolean started = false;
/**
* enabled this component
*/
protected boolean enabled = true;
/**
* number of session that no at this tomcat instanz hosted
*/
protected long numberOfSessions = 0;
protected String sessionIdAttribute = "org.apache.catalina.ha.session.JvmRouteOrignalSessionID";
/**
* The lifecycle event support for this component.
*/
protected LifecycleSupport lifecycle = new LifecycleSupport(this);
/*--Logic---------------------------------------------------*/
/**
* Return descriptive information about this implementation.
*/
public String getInfo() {
return (info);
}
/**
* set session id attribute to failed node for request.
*
* @return Returns the sessionIdAttribute.
*/
public String getSessionIdAttribute() {
return sessionIdAttribute;
}
/**
* get name of failed reqeust session attribute
*
* @param sessionIdAttribute
* The sessionIdAttribute to set.
*/
public void setSessionIdAttribute(String sessionIdAttribute) {
this.sessionIdAttribute = sessionIdAttribute;
}
/**
* @return Returns the number of migrated sessions.
*/
public long getNumberOfSessions() {
return numberOfSessions;
}
/**
* @return Returns the enabled.
*/
public boolean getEnabled() {
return enabled;
}
/**
* @param enabled
* The enabled to set.
*/
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
/**
* Detect possible the JVMRoute change at cluster backup node..
*
* @param request
* tomcat request being processed
* @param response
* tomcat response being processed
* @exception IOException
* if an input/output error has occurred
* @exception ServletException
* if a servlet error has occurred
*/
public void invoke(Request request, Response response) throws IOException,
ServletException {
if (getEnabled()
&& request.getContext() != null
&& request.getContext().getDistributable() ) {
// valve cluster can access manager - other cluster handle turnover
// at host level - hopefully!
Manager manager = request.getContext().getManager();
if (manager != null && (
(manager instanceof ClusterManager
&& getCluster() != null
&& getCluster().getManager(((ClusterManager)manager).getName()) != null)
||
(manager instanceof PersistentManager)))
handlePossibleTurnover(request, response);
}
// Pass this request on to the next valve in our pipeline
getNext().invoke(request, response);
}
/**
* handle possible session turn over.
*
* @see JvmRouteBinderValve#handleJvmRoute(Request, Response, String, String)
* @param request current request
* @param response current response
*/
protected void handlePossibleTurnover(Request request, Response response) {
String sessionID = request.getRequestedSessionId() ;
if (sessionID != null) {
long t1 = System.currentTimeMillis();
String jvmRoute = getLocalJvmRoute(request);
if (jvmRoute == null) {
if (log.isDebugEnabled())
log.debug(sm.getString("jvmRoute.missingJvmRouteAttribute"));
return;
}
handleJvmRoute( request, response, sessionID, jvmRoute);
if (log.isDebugEnabled()) {
long t2 = System.currentTimeMillis();
long time = t2 - t1;
log.debug(sm.getString("jvmRoute.turnoverInfo", new Long(time)));
}
}
}
/**
* get jvmroute from engine
*
* @param request current request
* @return return jvmRoute from ManagerBase or null
*/
protected String getLocalJvmRoute(Request request) {
Manager manager = getManager(request);
if(manager instanceof ManagerBase)
return ((ManagerBase) manager).getJvmRoute();
return null ;
}
/**
* get Cluster DeltaManager
*
* @param request current request
* @return manager or null
*/
protected Manager getManager(Request request) {
Manager manager = request.getContext().getManager();
if (log.isDebugEnabled()) {
if(manager != null)
log.debug(sm.getString("jvmRoute.foundManager", manager, request.getContext().getName()));
else
log.debug(sm.getString("jvmRoute.notFoundManager", manager, request.getContext().getName()));
}
return manager;
}
/**
* @return Returns the cluster.
*/
public CatalinaCluster getCluster() {
return cluster;
}
/**
* @param cluster The cluster to set.
*/
public void setCluster(CatalinaCluster cluster) {
this.cluster = cluster;
}
/**
* Handle jvmRoute stickyness after tomcat instance failed. After this
* correction a new Cookie send to client with new jvmRoute and the
* SessionID change propage to the other cluster nodes.
*
* @param request current request
* @param response
* Tomcat Response
* @param sessionId
* request SessionID from Cookie
* @param localJvmRoute
* local jvmRoute
*/
protected void handleJvmRoute(
Request request, Response response,String sessionId, String localJvmRoute) {
// get requested jvmRoute.
String requestJvmRoute = null;
int index = sessionId.indexOf(".");
if (index > 0) {
requestJvmRoute = sessionId
.substring(index + 1, sessionId.length());
}
if (requestJvmRoute != null && !requestJvmRoute.equals(localJvmRoute)) {
if (log.isDebugEnabled()) {
log.debug(sm.getString("jvmRoute.failover", requestJvmRoute,
localJvmRoute, sessionId));
}
Session catalinaSession = null;
try {
catalinaSession = getManager(request).findSession(sessionId);
} catch (IOException e) {
// Hups!
}
String id = sessionId.substring(0, index);
String newSessionID = id + "." + localJvmRoute;
// OK - turnover the session and inform other cluster nodes
if (catalinaSession != null) {
changeSessionID(request, response, sessionId, newSessionID,
catalinaSession);
numberOfSessions++;
} else {
try {
catalinaSession = getManager(request).findSession(newSessionID);
} catch (IOException e) {
// Hups!
}
if (catalinaSession != null) {
// session is rewrite at other request, rewrite this also
changeRequestSessionID(request, response, sessionId, newSessionID);
} else {
if (log.isDebugEnabled()) {
log.debug(sm.getString("jvmRoute.cannotFindSession",sessionId));
}
}
}
}
}
/**
* change session id and send to all cluster nodes
*
* @param request current request
* @param response current response
* @param sessionId
* original session id
* @param newSessionID
* new session id for node migration
* @param catalinaSession
* current session with original session id
*/
protected void changeSessionID(Request request,
Response response, String sessionId, String newSessionID, Session catalinaSession) {
lifecycle.fireLifecycleEvent("Before session migration",
catalinaSession);
catalinaSession.setId(newSessionID, false);
// FIXME: Why we remove change data from other running request?
// setId also trigger resetDeltaRequest!!
if (catalinaSession instanceof DeltaSession)
((DeltaSession) catalinaSession).resetDeltaRequest();
changeRequestSessionID(request, response, sessionId, newSessionID);
if (getCluster() != null) {
// now sending the change to all other clusternode!
ClusterManager manager = (ClusterManager)catalinaSession.getManager();
sendSessionIDClusterBackup(manager,request,sessionId, newSessionID);
}
lifecycle.fireLifecycleEvent("After session migration", catalinaSession);
if (log.isDebugEnabled()) {
log.debug(sm.getString("jvmRoute.changeSession", sessionId,
newSessionID));
}
}
/**
* Change Request Session id
* @param request current request
* @param response current response
* @param sessionId
* original session id
* @param newSessionID
* new session id for node migration
*/
protected void changeRequestSessionID(Request request, Response response, String sessionId, String newSessionID) {
request.changeSessionId(newSessionID);
// set orginal sessionid at request, to allow application detect the
// change
if (sessionIdAttribute != null && !"".equals(sessionIdAttribute)) {
if (log.isDebugEnabled()) {
log.debug(sm.getString("jvmRoute.set.orignalsessionid",sessionIdAttribute,sessionId));
}
request.setAttribute(sessionIdAttribute, sessionId);
}
}
/**
* Send the changed Sessionid to all clusternodes.
*
* @see JvmRouteSessionIDBinderListener#messageReceived(ClusterMessage)
* @param manager
* ClusterManager
* @param sessionId
* current failed sessionid
* @param newSessionID
* new session id, bind to the new cluster node
*/
protected void sendSessionIDClusterBackup(ClusterManager manager,Request request,String sessionId,
String newSessionID) {
if (!(getManager(request) instanceof BackupManager)) {
SessionIDMessage msg = new SessionIDMessage();
msg.setOrignalSessionID(sessionId);
msg.setBackupSessionID(newSessionID);
Context context = request.getContext();
msg.setContextPath(context.getPath());
msg.setHost(context.getParent().getName());
if(manager.doDomainReplication()) {
cluster.sendClusterDomain(msg);
} else {
cluster.send(msg);
}
}
}
/**
* Sets a new cookie for the given session id and response and see
* {@link org.apache.catalina.connector.Request#configureSessionCookie(javax.servlet.http.Cookie)}
*
* @param request current request
* @param response Tomcat Response
* @param sessionId The session id
*
* @deprecated Use {@link Request#changeSessionId(String)}
*/
protected void setNewSessionCookie(Request request,
Response response, String sessionId) {
if (response != null) {
Context context = request.getContext();
if (context.getCookies()) {
// set a new session cookie
String scName = context.getSessionCookieName();
if (scName == null) {
scName = Globals.SESSION_COOKIE_NAME;
}
Cookie newCookie = new Cookie(scName, sessionId);
newCookie.setMaxAge(-1);
String contextPath = null;
if (!response.getConnector().getEmptySessionPath() &&
(context != null)) {
if (context.getSessionCookiePath() != null) {
contextPath = context.getSessionCookiePath();
} else {
contextPath = context.getEncodedPath();
}
}
if ((contextPath != null) && (contextPath.length() > 0)) {
newCookie.setPath(contextPath);
} else {
newCookie.setPath("/");
}
if (context.getSessionCookieDomain() != null) {
newCookie.setDomain(context.getSessionCookieDomain());
}
if (request.isSecure()) {
newCookie.setSecure(true);
}
if (log.isDebugEnabled()) {
Object[] args = new Object[] {sessionId,
newCookie.getName(),
newCookie.getPath(),
new Boolean(newCookie.getSecure()),
new Boolean(context.getUseHttpOnly())};
log.debug(sm.getString("jvmRoute.newSessionCookie", args));
}
response.addCookieInternal(newCookie, context.getUseHttpOnly());
}
}
}
// ------------------------------------------------------ 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 add
*/
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 {
// Validate and update our current component state
if (started)
throw new LifecycleException(sm
.getString("jvmRoute.valve.alreadyStarted"));
lifecycle.fireLifecycleEvent(START_EVENT, null);
started = true;
if (cluster == null) {
Container hostContainer = getContainer();
// compatibility with JvmRouteBinderValve version 1.1
// ( setup at context.xml or context.xml.default )
if (!(hostContainer instanceof Host)) {
if (log.isWarnEnabled())
log.warn(sm.getString("jvmRoute.configure.warn"));
hostContainer = hostContainer.getParent();
}
if (hostContainer instanceof Host
&& ((Host) hostContainer).getCluster() != null) {
cluster = (CatalinaCluster) ((Host) hostContainer).getCluster();
} else {
Container engine = hostContainer.getParent() ;
if (engine instanceof Engine
&& ((Engine) engine).getCluster() != null) {
cluster = (CatalinaCluster) ((Engine) engine).getCluster();
}
}
}
if (log.isInfoEnabled()) {
log.info(sm.getString("jvmRoute.valve.started"));
if (cluster == null)
log.info(sm.getString("jvmRoute.noCluster"));
}
}
/**
* 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 {
// Validate and update our current component state
if (!started)
throw new LifecycleException(sm
.getString("jvmRoute.valve.notStarted"));
lifecycle.fireLifecycleEvent(STOP_EVENT, null);
started = false;
cluster = null;
numberOfSessions = 0;
if (log.isInfoEnabled())
log.info(sm.getString("jvmRoute.valve.stopped"));
}
}