Existe-t-il une option useDirtyFlag pour la configuration du cluster Tomcat 6?

Question

Dans Tomcat 5.0.x, vous pouviez définir useDirtyFlag = "false" sur pour forcer la réplication de la session après chaque requête plutôt que de rechercher les appels set/removeAttribute.

<Cluster className="org.apache.catalina.cluster.tcp.SimpleTcpCluster" 
       managerClassName="org.apache.catalina.cluster.session.SimpleTcpReplicationManager" 
       expireSessionsOnShutdown="false" 
       **useDirtyFlag="false"** 
       doClusterLog="true" 
       clusterLogName="clusterLog"> ... 

Les commentaires dans le server.xml a déclaré ceci peut être utilisé pour faire les travaux suivants:

<% 
    HashMap map = (HashMap)session.getAttribute("map"); 
    map.put("key","value"); 
%> 

-à-dire changer l'état d'un objet qui a déjà été mis à la session et vous pouvez être sûr que cet objet est toujours répliqué sur les autres nœuds du cluster.

Selon la documentation de Tomcat 6, vous n'avez que deux options "Manager" - DeltaManager & BackupManager ... aucun de ces éléments ne semble autoriser cette option. Dans mon test de la configuration par défaut:

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/> 

où vous obtenez le DeltaManager par défaut, il se comporte certainement comme useDirtyFlag = « true » (comme je pense).

Donc, ma question est: y a-t-il un équivalent dans Tomcat 6?

En regardant la source, je peux voir une implémentation de gestionnaire "org.apache.catalina.ha.session.SimpleTcpReplicationManager" qui a le useDirtyFlag mais les commentaires de javadoc dans cet état c'est "Tomcat Session Replication for Tomcat 4.0". Je ne sais pas si c'est bon à utiliser - je ne pense pas que ce n'est pas mentionné dans la documentation de la configuration du cluster principal.

Answer 1

Je posté essentiellement la même question sur la tomcat-users liste de diffusion et les réponses à ce ainsi que quelques informations dans le bugzilla tomcat ([43866]) m'a conduit aux conclusions suivantes:

1. Il y a pas équivalent à useDirtyFlag, si vous mettez des objets mutables (c'est-à-dire qui changent) dans la session, vous avez besoin d'une solution codée personnalisée. Un Tomcat ClusterValve semble être un endroit efficace pour cette solution - branchez-vous dans le mécanisme de cluster, manipulez les attributs pour faire apparaître à DeltaManager que tous les attributs de la session ont changé. Cela force la réplication de toute la session.

Etape 1: Ecrire les ForceReplicationValve (Prolonge ValveBase met en œuvre ClusterValve)

Je ne vais pas inclure toute la classe, mais le bit clé de la logique (prenant l'enregistrement et la vérification instanceof):

@Override 
public void invoke(Request request, Response response) 
     throws IOException, ServletException { 
    getNext().invoke(request, response); 
    Session session = request.getSessionInternal();   
    HttpSession deltaSession = (HttpSession) session; 
    for (Enumeration<String> names = deltaSession.getAttributeNames(); 
      names.hasMoreElements();) { 
     String name = names.nextElement(); 
     deltaSession.setAttribute(name, deltaSession.getAttribute(name)); 
    } 
} 

Étape 2: Modifier la configuration du cluster (en conf/server.xml)

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster" 
      channelSendOptions="8">   
    <Valve className="org.apache.catalina.ha.tcp.ForceReplicationValve"/> 
    <Valve className="org.apache.catalina.ha.tcp.ReplicationValve" 
      filter=".*\.gif;.*\.jpg;.*\.png;.*\.js;.*\.htm;.*\.html;.*\.txt;.*\.css;"/> 
    <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/> 

    <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/> 
    <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/> 
</Cluster> 

La réplication de la session sur tous les nœuds de cluster se produit désormais après chaque requête.

À côté: Notez le paramètre channelSendOptions. Cela remplace le replicationMode=asynchronous/synchronous/pooled de Tomcat 5.0.x.Voir le cluster documentation pour les valeurs int possibles.

Annexe: source complet Valve comme demandé

package org.apache.catalina.ha.tcp; 

import java.io.IOException; 
import java.util.Enumeration; 
import java.util.LinkedList; 
import java.util.List; 

import javax.servlet.ServletException; 
import javax.servlet.http.HttpSession; 

import org.apache.catalina.Lifecycle; 
import org.apache.catalina.LifecycleException; 
import org.apache.catalina.LifecycleListener; 
import org.apache.catalina.Session; 
import org.apache.catalina.connector.Request; 
import org.apache.catalina.connector.Response; 
import org.apache.catalina.ha.CatalinaCluster; 
import org.apache.catalina.ha.ClusterValve; 
import org.apache.catalina.ha.session.ReplicatedSession; 
import org.apache.catalina.ha.session.SimpleTcpReplicationManager; 
import org.apache.catalina.util.LifecycleSupport; 
//import org.apache.catalina.util.StringManager; 
import org.apache.catalina.valves.ValveBase; 

/** 
* <p>With the {@link SimpleTcpReplicationManager} effectively deprecated, this allows 
* mutable objects to be replicated in the cluster by forcing the "dirty" status on 
* every request.</p> 
* 
* @author Jon Brisbin (via post on tomcat-users http://markmail.org/thread/rdo3drcir75dzzrq) 
* @author Kevin Jansz 
*/ 
public class ForceReplicationValve extends ValveBase implements Lifecycle, ClusterValve { 
    private static org.apache.juli.logging.Log log = 
     org.apache.juli.logging.LogFactory.getLog(ForceReplicationValve.class); 

    @SuppressWarnings("hiding") 
    protected static final String info = "org.apache.catalina.ha.tcp.ForceReplicationValve/1.0"; 

// this could be used if ForceReplicationValve messages were setup 
// in org/apache/catalina/ha/tcp/LocalStrings.properties 
//  
// /** 
//  * The StringManager for this package. 
//  */ 
// @SuppressWarnings("hiding") 
// protected static StringManager sm = 
//  StringManager.getManager(Constants.Package); 

    /** 
    * Not actually required but this must implement {@link ClusterValve} to 
    * be allowed to be added to the Cluster. 
    */ 
    private CatalinaCluster cluster = null ; 

    /** 
    * Also not really required, implementing {@link Lifecycle} to allow 
    * initialisation and shutdown to be logged. 
    */ 
    protected LifecycleSupport lifecycle = new LifecycleSupport(this);  


    /** 
    * Default constructor 
    */ 
    public ForceReplicationValve() { 
     super(); 
     if (log.isInfoEnabled()) { 
      log.info(getInfo() + ": created"); 
     } 
    } 

    @Override 
    public String getInfo() { 
     return info; 
    } 

    @Override 
    public void invoke(Request request, Response response) throws IOException, 
      ServletException { 

     getNext().invoke(request, response); 

     Session session = null; 
     try { 
      session = request.getSessionInternal(); 
     } catch (Throwable e) { 
      log.error(getInfo() + ": Unable to perform replication request.", e); 
     } 

     String context = request.getContext().getName(); 
     String task = request.getPathInfo(); 
     if(task == null) { 
      task = request.getRequestURI(); 
     } 
     if (session != null) { 
      if (log.isDebugEnabled()) { 
       log.debug(getInfo() + ": [session=" + session.getId() + ", instanceof=" + session.getClass().getName() + ", context=" + context + ", request=" + task + "]"); 
      } 
      if (session instanceof ReplicatedSession) { 
       // it's a SimpleTcpReplicationManager - can just set to dirty 
       ((ReplicatedSession) session).setIsDirty(true); 
       if (log.isDebugEnabled()) { 
        log.debug(getInfo() + ": [session=" + session.getId() + ", context=" + context + ", request=" + task + "] maked DIRTY"); 
       } 
      } else { 
       // for everything else - cycle all attributes 
       List cycledNames = new LinkedList(); 

       // in a cluster where the app is <distributable/> this should be 
       // org.apache.catalina.ha.session.DeltaSession - implements HttpSession 
       HttpSession deltaSession = (HttpSession) session; 
       for (Enumeration<String> names = deltaSession.getAttributeNames(); names.hasMoreElements();) { 
        String name = names.nextElement(); 
        deltaSession.setAttribute(name, deltaSession.getAttribute(name)); 

        cycledNames.add(name);      
       } 

       if (log.isDebugEnabled()) { 
        log.debug(getInfo() + ": [session=" + session.getId() + ", context=" + context + ", request=" + task + "] cycled atrributes=" + cycledNames + ""); 
       } 
      } 
     } else { 
      String id = request.getRequestedSessionId(); 
      log.warn(getInfo() + ": [session=" + id + ", context=" + context + ", request=" + task + "] Session not available, unable to send session over cluster."); 
     } 
    } 


    /* 
    * ClusterValve methods - implemented to ensure this valve is not ignored by Cluster 
    */ 

    public CatalinaCluster getCluster() { 
     return cluster; 
    } 

    public void setCluster(CatalinaCluster cluster) { 
     this.cluster = cluster; 
    } 


    /* 
    * Lifecycle methods - currently implemented just for logging startup 
    */ 

    /** 
    * 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); 
    } 

    public void start() throws LifecycleException { 
     lifecycle.fireLifecycleEvent(START_EVENT, null); 
     if (log.isInfoEnabled()) { 
      log.info(getInfo() + ": started"); 
     } 
    } 

    public void stop() throws LifecycleException { 
     lifecycle.fireLifecycleEvent(STOP_EVENT, null); 
     if (log.isInfoEnabled()) { 
      log.info(getInfo() + ": stopped"); 
     } 
    } 

} 

Answer 2

Un grand merci à kevinjansz pour fournir la source de ForceReplicationValve.

J'ajusté pour tomcat7, ici il est si quelqu'un en a besoin:

package org.apache.catalina.ha.tcp; 

import java.io.IOException; 
import java.util.Enumeration; 
import java.util.LinkedList; 
import java.util.List; 

import javax.servlet.ServletException; 
import javax.servlet.http.HttpSession; 

import org.apache.catalina.Lifecycle; 
import org.apache.catalina.LifecycleException; 
import org.apache.catalina.LifecycleListener; 
import org.apache.catalina.Session; 
import org.apache.catalina.connector.Request; 
import org.apache.catalina.connector.Response; 
import org.apache.catalina.ha.CatalinaCluster; 
import org.apache.catalina.ha.ClusterValve; 
import org.apache.catalina.util.LifecycleSupport; 
import org.apache.catalina.valves.ValveBase; 
import org.apache.catalina.LifecycleState; 
// import org.apache.tomcat.util.res.StringManager; 

/** 
* <p>With the {@link SimpleTcpReplicationManager} effectively deprecated, this allows 
* mutable objects to be replicated in the cluster by forcing the "dirty" status on 
* every request.</p> 
* 
* @author Jon Brisbin (via post on tomcat-users http://markmail.org/thread/rdo3drcir75dzzrq) 
* @author Kevin Jansz 
*/ 
public class ForceReplicationValve extends ValveBase implements Lifecycle, ClusterValve { 
    private static org.apache.juli.logging.Log log = 
     org.apache.juli.logging.LogFactory.getLog(ForceReplicationValve.class); 

    @SuppressWarnings("hiding") 
    protected static final String info = "org.apache.catalina.ha.tcp.ForceReplicationValve/1.0"; 

// this could be used if ForceReplicationValve messages were setup 
// in org/apache/catalina/ha/tcp/LocalStrings.properties 
//  
// /** 
//  * The StringManager for this package. 
//  */ 
// @SuppressWarnings("hiding") 
// protected static StringManager sm = 
//  StringManager.getManager(Constants.Package); 

    /** 
    * Not actually required but this must implement {@link ClusterValve} to 
    * be allowed to be added to the Cluster. 
    */ 
    private CatalinaCluster cluster = null; 

    /** 
    * Also not really required, implementing {@link Lifecycle} to allow 
    * initialisation and shutdown to be logged. 
    */ 
    protected LifecycleSupport lifecycle = new LifecycleSupport(this);  


    /** 
    * Default constructor 
    */ 
    public ForceReplicationValve() { 
     super(); 
     if (log.isInfoEnabled()) { 
      log.info(getInfo() + ": created"); 
     } 
    } 

    @Override 
    public String getInfo() { 
     return info; 
    } 

    @Override 
    public void invoke(Request request, Response response) throws IOException, 
      ServletException { 

     getNext().invoke(request, response); 

     Session session = null; 
     try { 
      session = request.getSessionInternal(); 
     } catch (Throwable e) { 
      log.error(getInfo() + ": Unable to perform replication request.", e); 
     } 

     String context = request.getContext().getName(); 
     String task = request.getPathInfo(); 
     if(task == null) { 
      task = request.getRequestURI(); 
     } 
     if (session != null) { 
      if (log.isDebugEnabled()) { 
       log.debug(getInfo() + ": [session=" + session.getId() + ", instanceof=" + session.getClass().getName() + ", context=" + context + ", request=" + task + "]"); 
      } 
      //cycle all attributes 
      List<String> cycledNames = new LinkedList<String>(); 

      // in a cluster where the app is <distributable/> this should be 
      // org.apache.catalina.ha.session.DeltaSession - implements HttpSession 
      HttpSession deltaSession = (HttpSession) session; 
      for (Enumeration<String> names = deltaSession.getAttributeNames(); names.hasMoreElements();) { 
       String name = names.nextElement(); 
       deltaSession.setAttribute(name, deltaSession.getAttribute(name)); 

       cycledNames.add(name);      
      } 

      if (log.isDebugEnabled()) { 
       log.debug(getInfo() + ": [session=" + session.getId() + ", context=" + context + ", request=" + task + "] cycled atrributes=" + cycledNames + ""); 
      } 
     } else { 
      String id = request.getRequestedSessionId(); 
      log.warn(getInfo() + ": [session=" + id + ", context=" + context + ", request=" + task + "] Session not available, unable to send session over cluster."); 
     } 
    } 


    /* 
    * ClusterValve methods - implemented to ensure this valve is not ignored by Cluster 
    */ 

    public CatalinaCluster getCluster() { 
     return cluster; 
    } 

    public void setCluster(CatalinaCluster cluster) { 
     this.cluster = cluster; 
    } 


    /* 
    * Lifecycle methods - currently implemented just for logging startup 
    */ 

    /** 
    * 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); 
    } 

    protected synchronized void startInternal() throws LifecycleException { 
     setState(LifecycleState.STARTING); 
     if (log.isInfoEnabled()) { 
      log.info(getInfo() + ": started"); 
     } 
    } 

    protected synchronized void stopInternal() throws LifecycleException { 
     setState(LifecycleState.STOPPING); 
     if (log.isInfoEnabled()) { 
      log.info(getInfo() + ": stopped"); 
     } 
    } 

}