All Superinterfaces:

ParameterInclude

All Known Implementing Classes:

DefaultNodeManager
```
public interface NodeManager
extends ParameterInclude
```
This interface is responsible for handling configuration management. Configuraion changes include
- Rebooting an entire cluster, in which case, all nodes have to load the new Axis2 configuration in a consistent manner
- Deploying a new service to a cluster or undeploying a service from a cluster
- Changing the policies of a service deployed on the cluster
It is not mandatory to have a NodeManager in a node. In which case the cluster may be used only for High Availability 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.

The implementation of this interface is set by the ClusterBuilder, by reading the "configurationManager" element in the axis2.xml
e.g.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`commit()`	Second phase of the 2-phase commit protocol.
`void`	`exceptionOccurred(Throwable throwable)`	To notify other nodes that an Exception occurred, during the processing of a `NodeManagementCommand`
`void`	`prepare()`	First phase of the 2-phase commit protocol.
`void`	`rollback()`	Rollback whatever was done
`void`	`sendMessage(NodeManagementCommand command)`	Execute a NodeManagementCommand
`void`	`setConfigurationContext(ConfigurationContext configurationContext)`	Set the system's configuration context.

Methods inherited from interface org.apache.axis2.description.ParameterInclude
addParameter, deserializeParameters, getParameter, getParameters, isParameterLocked, removeParameter

- Method Detail
  - prepare
```
void prepare()
      throws ClusteringFault
```
    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
  - rollback
```
void rollback()
       throws ClusteringFault
```
    Rollback whatever was done
    
    Throws:
    
    ClusteringFault - If an error occurs while rolling back a cluster configuration transaction
  - commit
```
void commit()
     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
  - exceptionOccurred
```
void exceptionOccurred(Throwable throwable)
                throws ClusteringFault
```
    To notify other nodes that an Exception occurred, during the processing of a NodeManagementCommand
    
    Parameters:
    
    throwable - The throwable which has to be propogated to other nodes
    
    Throws:
    
    ClusteringFault - If an error occurs while processing the exception message
  - setConfigurationContext
```
void setConfigurationContext(ConfigurationContext configurationContext)
```
    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
    
    Parameters:
    
    configurationContext - The configuration context
  - sendMessage
```
void sendMessage(NodeManagementCommand command)
          throws ClusteringFault
```
    Execute a NodeManagementCommand
    
    Parameters:
    
    command - The command to be executed
    
    Throws:
    
    ClusteringFault - If an error occurs while sending the message

Interface NodeManager

Method Summary

Methods inherited from interface org.apache.axis2.description.ParameterInclude

Method Detail

prepare

rollback

commit

exceptionOccurred

setConfigurationContext

sendMessage