| Links Top Level Elements Executors Connectors Containers Nested Components Cluster Elements web.xml Other | The Cluster Valve object| Introduction |  | 
  
  A cluster valve is no different from any other Tomcat Valve.
  The cluster valves are interceptors in the invocation chain for HTTP requests, and the clustering implementation
  uses these valves to make intelligent decision around data and when data should be replicated. 
  A cluster valve must implement the org.apache.catalina.ha.ClusterValveinterface.
  This is a simple interface that extends theorg.apache.catalina.Valveinterface. | 
 | org.apache.catalina.ha.tcp.ReplicationValve |  | 
  The ReplicationValvewill notify the cluster at the end of an HTTP request
  so that the cluster can make a decision whether there is data to be replicated or not.| Attributes |  | 
    | Attribute | Description | 
|---|
 | className | Set value to org.apache.catalina.ha.tcp.ReplicationValve |  | filter | For known file extensions or urls, you can use this Valve to notify the
        cluster that the session has not been modified during this  request and
        the cluster doesn't have to probe the session managers for changes. If
        the request matches this filter pattern, the cluster assumes there has
        been no session change. An example filter would look like 
        filter=".*\.gif|.*\.js|.*\.jpeg|.*\.jpg|.*\.png|.*\.htm|.*\.html|.*\.css|.*\.txt"
        . The filter is a regular expression usingjava.util.regex. |  | primaryIndicator | Boolean value, so to true, and the replication valve will insert a request attribute with the name
        defined by the primaryIndicatorNameattribute.
        The value inserted into the request attribute is eitherBoolean.TRUEorBoolean.FALSE |  | primaryIndicatorName | Default value is org.apache.catalina.ha.tcp.isPrimarySessionThe value defined here is the name of the request attribute that contains the boolean value
        if the session is primary on this server or not. |  | statistics | Boolean value. Set to trueif you want the valve to collect request statistics.
        Default value isfalse | 
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 | org.apache.catalina.ha.session.JvmRouteBinderValve |  | 
  In case of a mod_jk failover, the JvmRouteBinderValvewill replace thejvmWorkerattribute in the session Id, to make future requests stick to this
  node. If you want fallback capability, don't enable this valve, but if you want your failover to stick,
  and for mod_jk not to have to keep probing the node that went down, you use this valve.| Attributes |  | 
    | Attribute | Description | 
|---|
 | className | org.apache.catalina.ha.session.JvmRouteBinderValve |  | enabled | Default value is trueRuntime attribute to turn on and off turn over of the session's jvmRoute value. |  | sessionIdAttribute | Old sessionid before failover is registered in request attributes with  this attribute.
        Default attribute name is org.apache.catalina.ha.session.JvmRouteOrignalSessionID. | 
 | 
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 | org.apache.catalina.ha.authenticator.ClusterSingleSignOn |  | 
  The ClusterSingleSignOnsupports feature of single sign on in cluster.
  By usingClusterSingleSignOn, the security identity authenticated
  by one web application is recognized by other web applications on the same virtual host,
  and it is propagated to other nodes in the cluster.See the Single Sign On special
    feature on the Host element for more information. Note: ClusterSingleSignOn can be configured at host level cluster only.
   | Attributes |  | 
    | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.ha.authenticator.ClusterSingleSignOn. |  | cookieDomain | Sets the host domain to be used for sso cookies. |  | mapSendOptions | The Valve uses a replicated map. You can setup the flag for how this
        map sends messages. The default value is 6(synchronous).
        Note that if you use asynchronous messaging it is possible for update
        messages to be processed by the receiving node in a different order to
        the order in which they were sent. |  | requireReauthentication | Default false. Flag to determine whether each request needs to be
        reauthenticated to the security Realm. If "true", this
        Valve uses cached security credentials (username and password) to
        reauthenticate to the Realm each request associated
        with an SSO session.  If "false", the Valve can itself authenticate
        requests based on the presence of a valid SSO cookie, without
        rechecking with the Realm. |  | rpcTimeout | The Valve uses a replicated map. This is the timeout for messages
        that transfer state to/from the other nodes in the cluster. If not
        specified, a default value of 15000milliseconds is used. |  | terminateOnStartFailure | Set to trueif you wish this Valve to fail if the
        underlying replication fails to start. If the Valve fails, then the
        associated container will fail to start. If you set this attribute to
        false, and the underlying replications fails to start, the Valve will
        start and it will attempt to join the cluster and start replication as
        part of the heartbeat process. If not specified, the default value offalseis used. |  | accessTimeout | The timeout for a ping message. If a remote map does not respond within
        this timeout period, its regarded as disappeared.
        Default value is 5000milliseconds. | 
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