org.gridgain.client

Interface GridClient

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

GridClientImpl

public interface GridClient
extends AutoCloseable

GridGain Java client API.

Contains functionality to get projections for accessing remote data and compute functionality, as well as provide listeners on topology changes.

You can obtain an instance of GridClient through GridClientFactory.start(GridClientConfiguration). Note that you can have multiple instances of GridClient running in the same VM. For information on how to start or stop Grid please refer to GridClientFactory class.

Use following methods to get access to remote cache functionality:

• data()
• data(String)

Use following methods to get access to remote compute functionality:

• compute()

Affinity Awareness

One of the unique properties of the GridGain remote clients is that they are affinity aware. In other words, both compute and data APIs will optionally contact exactly the node where the data is cached based on some affinity key. This allows for collocation of computations and data and avoids extra network hops that would be necessary if non-affinity nodes were contacted.

If client can't access some of grid nodes directly (for example due to security restrictions) either dedicated Router component could be used or some of Grid nodes could act as routers. See GridClientConfiguration.getRouters() for more details.

See Also:

GridClientCompute, GridClientData

Method Summary

Methods

Modifier and Type	Method and Description
void	addTopologyListener(GridClientTopologyListener lsnr) Adds topology listener.
void	close() Closes client instance.
GridClientCompute	compute() Gets a default compute projection.
boolean	connected() Indicates whether client is connected to remote Grid.
GridClientData	data() Gets a data projection for a default grid cache with null name.
GridClientData	data(String cacheName) Gets a data projection for grid cache with name cacheName.
UUID	id() Gets a unique client identifier.
void	removeTopologyListener(GridClientTopologyListener lsnr) Removes previously added topology listener.
Collection<GridClientTopologyListener>	topologyListeners() Gets an unmodifiable snapshot of topology listeners list.

Method Detail

id

UUID id()

Gets a unique client identifier. This identifier is generated by factory on client creation and used in identification and authentication procedure on server node.

Returns:

Generated client id.

data

GridClientData data()
                    throws GridClientException

Gets a data projection for a default grid cache with null name.

Returns:

Data projection for grid cache with null name.

Throws:

GridClientException - If client was closed.

data

GridClientData data(String cacheName)
                    throws GridClientException

Gets a data projection for grid cache with name cacheName. If no data configuration with given name was provided at client startup, an exception will be thrown.

Parameters:

cacheName - Grid cache name for which data projection should be obtained.

Returns:

Data projection for grid cache with name cacheName.

Throws:

GridClientException - If client was closed or no configuration with given name was provided.

compute

GridClientCompute compute()

Gets a default compute projection. Default compute projection will include all nodes in remote grid. Selection of node that will be connected to perform operations will be done according to GridClientLoadBalancer provided in client configuration or according to affinity if projection call involves affinity key.

More restricted projection configurations may be created with GridClientCompute methods.

Returns:

Default compute projection.

See Also:

GridClientCompute

addTopologyListener

void addTopologyListener(GridClientTopologyListener lsnr)

Adds topology listener. Remote grid topology is refreshed every GridClientConfiguration.getTopologyRefreshFrequency() milliseconds. If any node was added or removed, a listener will be notified.

Parameters:

lsnr - Listener to add.

removeTopologyListener

void removeTopologyListener(GridClientTopologyListener lsnr)

Removes previously added topology listener.

Parameters:

lsnr - Listener to remove.

topologyListeners

Collection<GridClientTopologyListener> topologyListeners()

Gets an unmodifiable snapshot of topology listeners list.

Returns:

List of topology listeners.

connected

boolean connected()

Indicates whether client is connected to remote Grid. In other words it allow to determine if client is able to communicate with Grid right now. If it can't all methods on Compute and Data projections throw GridClientDisconnectedException.

Connection status is updated in background together with topology update. See GridClientConfiguration.getTopologyRefreshFrequency() for more details on how background topology update works.

Note that due to asynchronous nature of topology update and connectivity detection this method gives no guarantees for subsequent calls for projections methods. It can be used only fo diagnostic and monitoring purposes.

Returns:

Whether client is connected to remote Grid.

close

void close()

Closes client instance. This method is identical to GridClientFactory.stop(clientId).

The method is invoked automatically on objects managed by the try-with-resources statement.

Specified by:

close in interface AutoCloseable