org.eclipse.rdf4j.federated

Class FederationManager

java.lang.Object

org.eclipse.rdf4j.federated.FederationManager

public class FederationManager
extends Object

The FederationManager manages all modules necessary for the runtime behavior. This includes for instance the federation layer instance, cache and statistics. It is Singleton and there can only be on federation instance at a time.

The factory FedXFactory provides various functions for initialization of FedX and should be used as the entry point for any application using FedX.

 Config.initialize(fedxConfig);
 List<Endpoint> members = ...                       // e.g. use EndpointFactory methods
 FedXRepository repo = FedXFactory.initializeFederation(endpoints);
 ReositoryConnection conn = repo.getConnection();

 // Do something with the connection, e.g. query evaluation
 repo.shutDown();
 

Author:

Andreas Schwarte

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FederationManager.FederationType The Federation type definition: Local, Remote, Hybrid

Constructor Summary

Constructors

Constructor and Description
FederationManager()

Method Summary

Modifier and Type	Method and Description
void	addAll(List<Endpoint> endpoints) Add the specified endpoints to the federation and take care for updating all structures.
void	addEndpoint(Endpoint e, boolean... updateStrategy) Add the specified endpoint to the federation.
WorkerUnionBase<BindingSet>	createWorkerUnion(QueryInfo queryInfo) Create an appropriate worker union for this federation, i.e.
Executor	getExecutor() Returns the managed Executor which takes for properly handling any configured FedXConfig.getTaskWrapper()
FedX	getFederation()
FederationManager.FederationType	getFederationType()
ControlledWorkerScheduler<BindingSet>	getJoinScheduler()
ControlledWorkerScheduler<BindingSet>	getLeftJoinScheduler()
FederationEvalStrategy	getStrategy()
ControlledWorkerScheduler<BindingSet>	getUnionScheduler()
void	init(FedX federation, FederationContext federationContext)
void	removeAll() Remove all endpoints from the federation, e.g.
void	removeEndpoint(Endpoint e, boolean... updateStrategy) Remove the specified endpoint from the federation.
void	reset() Reset the Scheduler instances, i.e.
void	shutDown() Shutdown the federation including the following operations:
void	updateStrategy() Update the federation evaluation strategy using the classification of endpoints as provided by Endpoint.getEndpointClassification():

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FederationManager

public FederationManager()

Method Detail

init

public void init(FedX federation,
                 FederationContext federationContext)

reset

public void reset()

Reset the Scheduler instances, i.e. abort all running threads and create a new scheduler instance.

getExecutor

public Executor getExecutor()

Returns the managed Executor which takes for properly handling any configured FedXConfig.getTaskWrapper()

Returns:

getFederation

public FedX getFederation()

getStrategy

public FederationEvalStrategy getStrategy()

getJoinScheduler

public ControlledWorkerScheduler<BindingSet> getJoinScheduler()

getLeftJoinScheduler

public ControlledWorkerScheduler<BindingSet> getLeftJoinScheduler()

getUnionScheduler

public ControlledWorkerScheduler<BindingSet> getUnionScheduler()

getFederationType

public FederationManager.FederationType getFederationType()

addEndpoint

public void addEndpoint(Endpoint e,
                        boolean... updateStrategy)
                 throws FedXRuntimeException

Add the specified endpoint to the federation. The federation must not contain a member with the same endpoint location.

Parameters:

e - the endpoint

updateStrategy - optional parameter, to determine if strategy is to be updated, default=true

Throws:

FedXRuntimeException - if the federation has already a member with the same location

addAll

public void addAll(List<Endpoint> endpoints)

Add the specified endpoints to the federation and take care for updating all structures.

Parameters:

endpoints - a list of endpoints to add

removeEndpoint

public void removeEndpoint(Endpoint e,
                           boolean... updateStrategy)
                    throws RepositoryException

Remove the specified endpoint from the federation.

Parameters:

e - the endpoint

updateStrategy - optional parameter, to determine if strategy is to be updated, default=true

Throws:

RepositoryException

removeAll

public void removeAll()
               throws RepositoryException

Remove all endpoints from the federation, e.g. to load a new preset. Repositories of the endpoints are shutDown, and the EndpointManager is added accordingly.

Throws:

RepositoryException

shutDown

public void shutDown()
              throws FedXException

Shutdown the federation including the following operations:

• shut down repositories of all federation members
• persist the cached information
• clear the endpoint manager

Throws:

FedXException - if an error occurs while shutting down the federation

createWorkerUnion

public WorkerUnionBase<BindingSet> createWorkerUnion(QueryInfo queryInfo)

Create an appropriate worker union for this federation, i.e. a synchronous worker union for local federations and a multithreaded worker union for remote & hybrid federations.

Returns:

the WorkerUnionBase

See Also:

ControlledWorkerUnion, SynchronousWorkerUnion

updateStrategy

public void updateStrategy()

Update the federation evaluation strategy using the classification of endpoints as provided by Endpoint.getEndpointClassification():

Which strategy is applied depends on FederationEvaluationStrategyFactory. Default strategies:

• local federation: SailFederationEvalStrategy
• endpoint federation: SparqlFederationEvalStrategy
• hybrid federation: SparqlFederationEvalStrategy