org.apache.axis2.clustering.state

Interface StateManager

All Superinterfaces:

ParameterInclude

public interface StateManager
extends ParameterInclude

This interface is responsible for handling context replication. The property changes in the Axis2 context hierarchy in this node, are propagated to all other nodes in the cluster.

It is not mandatory to have a StateManager in a node. If we are not interested in High Availability, we may disable context replication by commenting out the "contextManager" section in the axis2.xml cluster configuration section. In such a scenatio, the cluster will be used only for the purpose of Scalability

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

e.g.

Method Summary

Modifier and Type	Method and Description
java.util.Map	getReplicationExcludePatterns() Get all the excluded context property name patterns
boolean	isContextClusterable(AbstractContext context) This is a check to see whether the properties in an instance of AbstractContext should be replicated.
void	removeContext(AbstractContext context) This method is called when AbstractContext is removed from the system
void	replicateState(StateClusteringCommand command) Replicate state using a custom StateClusteringCommand
void	setConfigurationContext(ConfigurationContext configurationContext) Set the system's configuration context.
void	setReplicationExcludePatterns(java.lang.String contextType, java.util.List patterns) All properties in the context with type contextType which have names that match the specified pattern will be excluded from replication.
void	updateContext(AbstractContext context) This method is called when properties in an AbstractContext are updated.
void	updateContext(AbstractContext context, java.lang.String[] propertyNames) This method is called when one need to update/replicate only certains properties in the specified context
void	updateContexts(AbstractContext[] contexts) This method is called when properties in a collection of AbstractContexts are updated.

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

addParameter, deserializeParameters, getParameter, getParameters, isParameterLocked, removeParameter

Method Detail

updateContext

void updateContext(AbstractContext context)
            throws ClusteringFault

This method is called when properties in an AbstractContext are updated. This could be addition of new properties, modifications of existing properties or removal of properties.

Parameters:

context - The context to be replicated

Throws:

ClusteringFault - If replication fails

updateContext

void updateContext(AbstractContext context,
                   java.lang.String[] propertyNames)
            throws ClusteringFault

This method is called when one need to update/replicate only certains properties in the specified context

Parameters:

context - The AbstractContext containing the properties to be replicated

propertyNames - The names of the specific properties that should be replicated

Throws:

ClusteringFault - If replication fails

updateContexts

void updateContexts(AbstractContext[] contexts)
             throws ClusteringFault

This method is called when properties in a collection of AbstractContexts are updated. This could be addition of new properties, modifications of existing properties or removal of properties.

Parameters:

contexts - The AbstractContexts containing the properties to be replicated

Throws:

ClusteringFault - If replication fails

replicateState

void replicateState(StateClusteringCommand command)
             throws ClusteringFault

Replicate state using a custom StateClusteringCommand

Parameters:

command - The custom StateClusteringCommand which can be used for replicating state

Throws:

ClusteringFault - If replication fails

removeContext

void removeContext(AbstractContext context)
            throws ClusteringFault

This method is called when AbstractContext is removed from the system

Parameters:

context - The AbstractContext to be removed

Throws:

ClusteringFault - If context removal fails

isContextClusterable

boolean isContextClusterable(AbstractContext context)

This is a check to see whether the properties in an instance of AbstractContext should be replicated. This allows an implementer to dissallow the replication of properties stored in a certain type of context

Parameters:

context - The instance of AbstractContext under consideration

Returns:

True - if the provided AbstractContext is clusterable

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

setReplicationExcludePatterns

void setReplicationExcludePatterns(java.lang.String contextType,
                                   java.util.List patterns)

All properties in the context with type contextType which have names that match the specified pattern will be excluded from replication.

Only prefixes and suffixes are allowed. e.g. the local_* pattern indicates that all property names starting with local_ should be omitted from replication. *_local pattern indicated that all property names ending with _local should be omitted from replication. * pattern indicates that all properties should be excluded.

Generally, we can use the context class name as the context type.

Parameters:

contextType - The type of the context such as org.apache.axis2.context.ConfigurationContext, org.apache.axis2.context.ServiceGroupContext & org.apache.axis2.context.ServiceContext. Also "defaults" is a special type, which will apply to all contexts

patterns - The patterns

getReplicationExcludePatterns

java.util.Map getReplicationExcludePatterns()

Get all the excluded context property name patterns

Returns:

All the excluded pattern of all the contexts. The key of the Map is the the contextType. See setReplicationExcludePatterns(String,List). The values are of type List of String Objects, which are a collection of patterns to be excluded.

See Also:

setReplicationExcludePatterns(String, java.util.List)