modules/kernel/src/org/apache/axis2/clustering/ClusteringAgent.java - axis-axis2-java-core - Git at Google

 /*
  * 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.axis2.clustering;

 import org.apache.axis2.clustering.management.NodeManager;
 import org.apache.axis2.clustering.management.GroupManagementAgent;
 import org.apache.axis2.clustering.state.StateManager;
 import org.apache.axis2.context.ConfigurationContext;
 import org.apache.axis2.description.ParameterInclude;

 import java.util.List;
 import java.util.Set;

 /**
  * <p>
  * This is the main interface in the Axis2 clustering implementation.
  * In order to plug-in a new clustering implementation, this interface has to be
  * implemented.
  * </p>
  * <p>
  * The initilization of a node in the cluster is handled here. It is also responsible for getting
  * this node to join the cluster. This node should not process any Web services requests until it
  * successfully joins the cluster. Generally, this node will also need to obtain the state
  * information and/or configuration information from a neighboring node.
  * This interface is also responsible for
  * properly instantiating a {@link org.apache.axis2.clustering.state.StateManager} &
  * {@link org.apache.axis2.clustering.management.NodeManager}. In the case of
  * a static <a href="http://blog.afkham.org/2008/05/group-membership-management-schemes.html">
  * membership scheme</a>,
  * this members are read from the axis2.xml file and added to the ClusteringAgent.
  * </p>
  * <p>
  * In the axis2.xml, the instance of this interface is specified using the "clustering"
  * class attribute.
  * e.g.
  * <code><b>
  * <nobr>&lt;clustering class="org.apache.axis2.clustering.tribes.TribesClusterAgent"&gt;</nobr>
  * </b>
  * </code>
  * specifies that the TribesClusterAgent class is the instance of this interface that
  * needs to be used.
  * </p>
  * <p>
  * There can also be several "parameter" elements, which are children of the "clustering" element
  * in the axis2.xml file. Generally, these parameters will be specific to the ClusteringAgent
  * implementation.
  * </p>
  */
 public interface ClusteringAgent extends ParameterInclude {

     /**
      * Initialize this node, and join the cluster
      *
      * @throws ClusteringFault If an error occurs while initializing this node or joining the cluster
      */
     void init() throws ClusteringFault;

     /**
      * Do cleanup & leave the cluster
      */
     void finalize();

     /**
      * @return The StateManager
      */
     StateManager getStateManager();

     /**
      * @return The NodeManager
      */
     NodeManager getNodeManager();

     /**
      * Set the StateManager corresponding to this ClusteringAgent. This is an optional attribute.
      * We can have a cluster with no context replication, in which case the contextManager will be
      * null. This value is set by the {@link org.apache.axis2.deployment.ClusterBuilder}, by
      * reading the  "contextManager" element in the axis2.xml
      * <p/>
      * e.g.
      * <code>
      * <b>
      * <contextManager class="org.apache.axis2.cluster.configuration.TribesContextManager">
      * </b>
      * </code>
      *
      * @param stateManager The StateManager instance
      */
     void setStateManager(StateManager stateManager);

     /**
      * Set the NodeManager corresponding to this ClusteringAgent. This is an optional attribute.
      * We can have a cluster with no configuration management, in which case the configurationManager
      * will be null. This value is set by the {@link org.apache.axis2.deployment.ClusterBuilder}, by
      * reading the  "configurationManager" element in the axis2.xml
      * <p/>
      * e.g.
      * <code>
      * <b>
      * <configurationManager class="org.apache.axis2.cluster.configuration.TribesConfigurationManager">
      * </b>
      * </code>
      *
      * @param nodeManager The NodeManager instance
      */
     void setNodeManager(NodeManager nodeManager);

     /**
      * Disconnect this node from the cluster. This node will no longer receive membership change
      * notifications, state change messages or configuration change messages. The node will be "
      * "standing alone" once it is shutdown. However, it has to continue to process Web service
      * requests.
      *
      * @throws ClusteringFault If an error occurs while leaving the cluster
      */
     void shutdown() throws ClusteringFault;

     /**
      * Set the system's configuration context. This will be used by the clustering implementations
      * to get information about the Axis2 environment and to correspond with the Axis2 environment
      *
      * @param configurationContext The configuration context
      */
     void setConfigurationContext(ConfigurationContext configurationContext);

     /**
      * Set the static members of the cluster. This is used only with
      * <a href="http://blog.afkham.org/2008/05/group-membership-management-schemes.html">
      * static group membership </a>
      *
      * @param members Members to be added
      */
     void setMembers(List<Member> members);

     /**
      * Get the list of members in a
      * <a href="http://blog.afkham.org/2008/05/group-membership-management-schemes.html">
      * static group
      * </a>
      *
      * @return The members if static group membership is used. If any other membership scheme is used,
      *         the values returned may not be valid
      */
     List<Member> getMembers();

     /**
      * Get the number of members alive.
      *
      * @return the number of members alive.
      */
     int getAliveMemberCount();

     /**
      * Set the load balance event handler which will be notified when load balance events occur.
      * This will be valid only when this node is running in loadBalance mode
      *
      * @param agent      The GroupManagementAgent to be added
      * @param applicationDomain The application domain which is handled by the GroupManagementAgent
      */
     void addGroupManagementAgent(GroupManagementAgent agent, String applicationDomain);

     /**
      * Add a GroupManagementAgent to an application domain + sub-domain
      * @param agent  The GroupManagementAgent to be added
      * @param applicationDomain  The application domain which is handled by the GroupManagementAgent
      * @param applicationSubDomain The application sub-domain which is handled by the GroupManagementAgent
      */
     void addGroupManagementAgent(GroupManagementAgent agent, String applicationDomain,
                                  String applicationSubDomain);

     /**
      * Get the GroupManagementAgent which corresponds to the <code>applicationDomain</code>
      * This will be valid only when this node is running in groupManagement
      *
      * @param applicationDomain The application domain to which the application nodes being
      *                          load balanced belong to
      * @return GroupManagementAgent which corresponds to the <code>applicationDomain</code>
      */
     GroupManagementAgent getGroupManagementAgent(String applicationDomain);

     /**
      * Get the GroupManagementAgent which corresponds to the <code>applicationDomain + sub-domain</code>
      * @param applicationDomain  The application domain which is handled by the GroupManagementAgent
      * @param applicationSubDomain The application sub-domain which is handled by the GroupManagementAgent
      * @return  GroupManagementAgent which corresponds to the <code>applicationDomain + sub-domain</code>
      */
     GroupManagementAgent getGroupManagementAgent(String applicationDomain,
                                                  String applicationSubDomain);

     /**
      * Get all the domains that this ClusteringAgent belongs to
      *
      * @return the domains of this ClusteringAgent
      */
     Set<String> getDomains();

     /**
      * Checks whether this member is the coordinator for the cluster
      *
      * @return true if this member is the coordinator, and false otherwise
      */
     boolean isCoordinator();


     /**
      * Send a message to all members in this member's primary cluster
      *
      * @param msg  The message to be sent
      * @param isRpcMessage Indicates whether the message has to be sent in RPC mode
      * @return A list of responses if the message is sent in RPC mode
      * @throws ClusteringFault If an error occurs while sending the message
      */
     List<ClusteringCommand> sendMessage(ClusteringMessage msg, boolean isRpcMessage) throws ClusteringFault;
 }
	/*
	* 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.axis2.clustering;

	import org.apache.axis2.clustering.management.NodeManager;
	import org.apache.axis2.clustering.management.GroupManagementAgent;
	import org.apache.axis2.clustering.state.StateManager;
	import org.apache.axis2.context.ConfigurationContext;
	import org.apache.axis2.description.ParameterInclude;

	import java.util.List;
	import java.util.Set;

	/**
	* <p>
	* This is the main interface in the Axis2 clustering implementation.
	* In order to plug-in a new clustering implementation, this interface has to be
	* implemented.
	* </p>
	* <p>
	* The initilization of a node in the cluster is handled here. It is also responsible for getting
	* this node to join the cluster. This node should not process any Web services requests until it
	* successfully joins the cluster. Generally, this node will also need to obtain the state
	* information and/or configuration information from a neighboring node.
	* This interface is also responsible for
	* properly instantiating a {@link org.apache.axis2.clustering.state.StateManager} &
	* {@link org.apache.axis2.clustering.management.NodeManager}. In the case of
	* a static <a href="http://blog.afkham.org/2008/05/group-membership-management-schemes.html">
	* membership scheme</a>,
	* this members are read from the axis2.xml file and added to the ClusteringAgent.
	* </p>
	* <p>
	* In the axis2.xml, the instance of this interface is specified using the "clustering"
	* class attribute.
	* e.g.
	* <code><b>
	* <nobr><clustering class="org.apache.axis2.clustering.tribes.TribesClusterAgent"></nobr>
	* </b>
	* </code>
	* specifies that the TribesClusterAgent class is the instance of this interface that
	* needs to be used.
	* </p>
	* <p>
	* There can also be several "parameter" elements, which are children of the "clustering" element
	* in the axis2.xml file. Generally, these parameters will be specific to the ClusteringAgent
	* implementation.
	* </p>
	*/
	public interface ClusteringAgent extends ParameterInclude {

	/**
	* Initialize this node, and join the cluster
	*
	* @throws ClusteringFault If an error occurs while initializing this node or joining the cluster
	*/
	void init() throws ClusteringFault;

	/**
	* Do cleanup & leave the cluster
	*/
	void finalize();

	/**
	* @return The StateManager
	*/
	StateManager getStateManager();

	/**
	* @return The NodeManager
	*/
	NodeManager getNodeManager();

	/**
	* Set the StateManager corresponding to this ClusteringAgent. This is an optional attribute.
	* We can have a cluster with no context replication, in which case the contextManager will be
	* null. This value is set by the {@link org.apache.axis2.deployment.ClusterBuilder}, by
	* reading the "contextManager" element in the axis2.xml
	* <p/>
	* e.g.
	* <code>
	* <b>
	* <contextManager class="org.apache.axis2.cluster.configuration.TribesContextManager">
	* </b>
	* </code>
	*
	* @param stateManager The StateManager instance
	*/
	void setStateManager(StateManager stateManager);

	/**
	* Set the NodeManager corresponding to this ClusteringAgent. This is an optional attribute.
	* We can have a cluster with no configuration management, in which case the configurationManager
	* will be null. This value is set by the {@link org.apache.axis2.deployment.ClusterBuilder}, by
	* reading the "configurationManager" element in the axis2.xml
	* <p/>
	* e.g.
	* <code>
	* <b>
	* <configurationManager class="org.apache.axis2.cluster.configuration.TribesConfigurationManager">
	* </b>
	* </code>
	*
	* @param nodeManager The NodeManager instance
	*/
	void setNodeManager(NodeManager nodeManager);

	/**
	* Disconnect this node from the cluster. This node will no longer receive membership change
	* notifications, state change messages or configuration change messages. The node will be "
	* "standing alone" once it is shutdown. However, it has to continue to process Web service
	* requests.
	*
	* @throws ClusteringFault If an error occurs while leaving the cluster
	*/
	void shutdown() throws ClusteringFault;

	/**
	* Set the system's configuration context. This will be used by the clustering implementations
	* to get information about the Axis2 environment and to correspond with the Axis2 environment
	*
	* @param configurationContext The configuration context
	*/
	void setConfigurationContext(ConfigurationContext configurationContext);

	/**
	* Set the static members of the cluster. This is used only with
	* <a href="http://blog.afkham.org/2008/05/group-membership-management-schemes.html">
	* static group membership </a>
	*
	* @param members Members to be added
	*/
	void setMembers(List<Member> members);

	/**
	* Get the list of members in a
	* <a href="http://blog.afkham.org/2008/05/group-membership-management-schemes.html">
	* static group
	* </a>
	*
	* @return The members if static group membership is used. If any other membership scheme is used,
	* the values returned may not be valid
	*/
	List<Member> getMembers();

	/**
	* Get the number of members alive.
	*
	* @return the number of members alive.
	*/
	int getAliveMemberCount();

	/**
	* Set the load balance event handler which will be notified when load balance events occur.
	* This will be valid only when this node is running in loadBalance mode
	*
	* @param agent The GroupManagementAgent to be added
	* @param applicationDomain The application domain which is handled by the GroupManagementAgent
	*/
	void addGroupManagementAgent(GroupManagementAgent agent, String applicationDomain);

	/**
	* Add a GroupManagementAgent to an application domain + sub-domain
	* @param agent The GroupManagementAgent to be added
	* @param applicationDomain The application domain which is handled by the GroupManagementAgent
	* @param applicationSubDomain The application sub-domain which is handled by the GroupManagementAgent
	*/
	void addGroupManagementAgent(GroupManagementAgent agent, String applicationDomain,
	String applicationSubDomain);

	/**
	* Get the GroupManagementAgent which corresponds to the <code>applicationDomain</code>
	* This will be valid only when this node is running in groupManagement
	*
	* @param applicationDomain The application domain to which the application nodes being
	* load balanced belong to
	* @return GroupManagementAgent which corresponds to the <code>applicationDomain</code>
	*/
	GroupManagementAgent getGroupManagementAgent(String applicationDomain);

	/**
	* Get the GroupManagementAgent which corresponds to the <code>applicationDomain + sub-domain</code>
	* @param applicationDomain The application domain which is handled by the GroupManagementAgent
	* @param applicationSubDomain The application sub-domain which is handled by the GroupManagementAgent
	* @return GroupManagementAgent which corresponds to the <code>applicationDomain + sub-domain</code>
	*/
	GroupManagementAgent getGroupManagementAgent(String applicationDomain,
	String applicationSubDomain);

	/**
	* Get all the domains that this ClusteringAgent belongs to
	*
	* @return the domains of this ClusteringAgent
	*/
	Set<String> getDomains();

	/**
	* Checks whether this member is the coordinator for the cluster
	*
	* @return true if this member is the coordinator, and false otherwise
	*/
	boolean isCoordinator();


	/**
	* Send a message to all members in this member's primary cluster
	*
	* @param msg The message to be sent
	* @param isRpcMessage Indicates whether the message has to be sent in RPC mode
	* @return A list of responses if the message is sent in RPC mode
	* @throws ClusteringFault If an error occurs while sending the message
	*/
	List<ClusteringCommand> sendMessage(ClusteringMessage msg, boolean isRpcMessage) throws ClusteringFault;
	}