是否有用于Tomcat 6群集配置的useDirtyFlag选项？
在Tomcat 5.0.x中，您可以设置useDirtyFlag =“false”以在每次请求后强制复制会话，而不是检查set / removeAttribute调用。
... server.xml中的注释表明这可以用于进行以下工作：
即更改已放入会话的对象的状态，并确保此对象仍可复制到群集中的其他节点。
根据Tomcat 6文档，您只有两个“管理器”选项 – DeltaManager和BackupManager ……这些选项似乎都不允许此选项或任何类似选项。 在我的测试中默认设置：
默认情况下，你得到DeltaManager，它肯定表现为useDirtyFlag =“true”（正如我所料）。
所以我的问题是 – Tomcat 6中是否有相同的内容？
查看源代码，我可以看到一个管理器实现“org.apache.catalina.ha.session.SimpleTcpReplicationManager”，它确实有useDirtyFlag，但javadoc注释在这种状态下它是“Tomcat会话复制为Tomcat 4.0”…我不知道知道这是否可以使用 – 我猜不是因为主集群配置文档中没有提到它。
我在tomcat-users邮件列表上发布了基本相同的问题，对此的回复以及tomcat bugzilla中的一些信息（[43866]）使我得出以下结论：
- 没有与useDirtyFlag等效的东西，如果您在会话中放置可变（即更改）对象，则需要自定义编码解决方案。
- Tomcat ClusterValve似乎是这个解决方案的一个有效位置 – 插入集群机制，操纵属性使DeltaManager中的所有属性都发生了变化。 这会强制复制整个会话。
第1步：编写ForceReplicationValve （扩展ValveBase实现ClusterValve ）
我不会包括整个类，而是逻辑的关键位（取出日志记录和instanceof检查）：
@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 names = deltaSession.getAttributeNames(); names.hasMoreElements(); ) { String name = names.nextElement(); deltaSession.setAttribute(name, deltaSession.getAttribute(name)); } }
第2步：更改集群配置（在conf/server.xml ）
现在，每次请求后都会将会话复制到所有群集节点。
旁白：注意channelSendOptions设置。 这将替换Tomcat 5.0.x中的replicationMode=asynchronous/synchronous/pooled poo。 有关可能的int值，请参阅集群文档 。
附录：根据要求提供完整阀门
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; /** * With the {@link SimpleTcpReplicationManager} effectively deprecated, this allows * mutable objects to be replicated in the cluster by forcing the "dirty" status on * every request.
* * @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 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"); } } }
非常感谢kevinjansz为ForceReplicationValve提供源代码。
我为Tomcat7调整了它，如果有人需要它：
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; /** * With the {@link SimpleTcpReplicationManager} effectively deprecated, this allows * mutable objects to be replicated in the cluster by forcing the "dirty" status on * every request.
* * @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 cycledNames = new LinkedList (); // in a cluster where the app is 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"); } } }