/*
* 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.configuration;
import org.apache.axis2.clustering.ClusteringFault;
import org.apache.axis2.context.ConfigurationContext;
import org.apache.axis2.description.ParameterInclude;
/**
* <p>
* This interface is responsible for handling configuration management. Configuraion changes include
* <p/>
* <ul>
* <li>Rebooting an entire cluster, in which case, all nodes have to load the new Axis2 configuration
* in a consistent manner
* </li>
* <li>
* Deploying a new service to a cluster or undeploying a service from a cluster
* </li>
* <li>
* Changing the policies of a service deployed on the cluster
* </li>
* </ul>
* </p>
* <p>
* It is not mandatory to have a ConfigurationManager in a node. In which case the cluster may be
* used only for <a href="http://afkham.org/2008/05/definition-of-high-availability.html">
* High Availability</a> through context replication. However, it is difficult to imagine that
* a cluster will be deployed in production with only context replication but without cluster
* configuration management.
* </p>
* <p>
* The implementation of this interface 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>
* </p>
*/
public interface ConfigurationManager extends ParameterInclude {
// ###################### Configuration management methods ##########################
/**
* Load a set of service groups
*
* @param serviceGroupNames The set of service groups to be loaded
* @throws ClusteringFault If an error occurs while loading service groups
*/
void loadServiceGroups(String[] serviceGroupNames) throws ClusteringFault;
/**
* Unload a set of service groups
*
* @param serviceGroupNames The set of service groups to be unloaded
* @throws ClusteringFault If an error occurs while unloading service groups
*/
void unloadServiceGroups(String[] serviceGroupNames) throws ClusteringFault;
/**
* Apply a policy to a service
*
* @param serviceName The name of the service to which this policy needs to be applied
* @param policy The serialized policy to be applied to the service
* @throws ClusteringFault If an error occurs while applying service policies
*/
void applyPolicy(String serviceName, String policy) throws ClusteringFault;
/**
* Reload the entire configuration of an Axis2 Node
*
* @throws ClusteringFault If an error occurs while reinitializing Axis2
*/
void reloadConfiguration() throws ClusteringFault;
// ###################### Transaction management methods ##########################
/**
* First phase of the 2-phase commit protocol.
* Notifies a node that it needs to prepare to switch to a new configuration.
*
* @throws ClusteringFault If an error occurs while preparing to commit
*/
void prepare() throws ClusteringFault;
/**
* Rollback whatever was done
*
* @throws ClusteringFault If an error occurs while rolling back a cluster configuration
* transaction
*/
void rollback() throws ClusteringFault;
/**
* Second phase of the 2-phase commit protocol.
* Notifies a node that it needs to switch to a new configuration.
*
* @throws ClusteringFault If an error occurs while committing a cluster configuration
* transaction
*/
void commit() throws ClusteringFault;
// ######################## General management methods ############################
/**
* To notify other nodes that an Exception occurred, during the processing
* of a {@link ConfigurationClusteringCommand}
*
* @param throwable The throwable which has to be propogated to other nodes
* @throws org.apache.axis2.clustering.ClusteringFault
* If an error occurs while processing the
* exception message
*/
void exceptionOccurred(Throwable throwable) throws ClusteringFault;
/**
* For registering a configuration event listener.
*
* @param listener The ConfigurationManagerListener instance
*/
void setConfigurationManagerListener(ConfigurationManagerListener listener);
/**
* 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);
}
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