org.gridgain.grid

Interface GridProjection

All Known Subinterfaces:

Grid, GridEx, GridProjectionEx

All Known Implementing Classes:

GridKernal, GridProjectionAdapter

public interface GridProjection

Defines grid projection which represents a common functionality over a group of nodes. The Grid interface itself also extends GridProjection which makes an instance of Grid a projection over all grid nodes.

Clustering

Grid projection allows to group grid nodes into various subgroups to perform distributed operations on them. All 'forXXX(...)' methods will create a child grid projection from existing projection. If you create a new projection from current one, then the resulting projection will include a subset of nodes from current projection. The following code snippet shows how to create and nest grid projections:

 Grid g = GridGain.grid();

 // Projection over remote nodes.
 GridProjection remoteNodes = g.forRemotes();

 // Projection over random remote node.
 GridProjection randomNode = remoteNodes.forRandom();

 // Projection over all nodes with cache named "myCache" enabled.
 GridProjection cacheNodes = g.forCache("myCache");

 // Projection over all nodes that have user attribute "group" set to value "worker".
 GridProjection workerNodes = g.forAttribute("group", "worker");
 

Features

Grid projection provides the following functionality over the underlying group of nodes:

• GridCompute - functionality for executing tasks and closures over nodes in this projection.
• GridMessaging - functionality for topic-based message exchange over nodes in this projection.
• GridEvents - functionality for querying and listening to events on nodes in this projection.

Method Summary

Methods

Modifier and Type	Method and Description
GridCompute	compute() Gets compute functionality over this grid projection.
GridEvents	events() Gets events functionality over this grid projection.
GridProjection	forAttribute(String name, String val) Creates projection for nodes containing given name and value specified in user attributes.
GridProjection	forCache(String cacheName, String... cacheNames) Creates projection for all nodes that have cache with specified name running.
GridProjection	forDaemons() Gets projection consisting from the daemon nodes in this projection.
GridProjection	forHost(GridNode node) Gets grid projection consisting from the nodes in this projection residing on the same host as given node.
GridProjection	forNode(GridNode node, GridNode... nodes) Creates a grid projection for the given node.
GridProjection	forNodeId(UUID id, UUID... ids) Creates a grid projection for a node with specified ID.
GridProjection	forNodeIds(Collection<UUID> ids) Creates a grid projection over nodes with specified node IDs.
GridProjection	forNodes(Collection<? extends GridNode> nodes) Creates a grid projection over a given set of nodes.
GridProjection	forOthers(GridNode node, GridNode... nodes) Creates a grid projection for nodes other than given nodes.
GridProjection	forOthers(GridProjection prj) Creates a grid projection for nodes not included into given projection.
GridProjection	forPredicate(GridPredicate<GridNode> p) Creates a grid projection which includes all nodes that pass the given predicate filter.
GridProjection	forRandom() Creates grid projection with one random node from current projection.
GridProjection	forRemotes() Gets grid projection consisting from the nodes in this projection excluding the local node.
GridProjection	forStreamer(String streamerName, String... streamerNames) Creates projection for all nodes that have streamer with specified name running.
Grid	grid() Gets instance of grid.
GridMessaging	message() Gets messaging functionality over this grid projection.
GridProjectionMetrics	metrics() Gets a metrics snapshot for this projection.
GridNode	node() Gets first node from the list of nodes in this projection.
GridNode	node(UUID nid) Gets a node for given ID from this grid projection.
Collection<GridNode>	nodes() Gets read-only collections of nodes in this projection.
GridPredicate<GridNode>	predicate() Gets predicate that defines a subset of nodes for this projection.

Method Detail

grid

Grid grid()

Gets instance of grid.

Returns:

Grid instance.

compute

GridCompute compute()

Gets compute functionality over this grid projection. All operations on the returned GridCompute instance will only include nodes from this projection.

Returns:

Compute instance over this grid projection.

message

GridMessaging message()

Gets messaging functionality over this grid projection. All operations on the returned GridMessaging instance will only include nodes from this projection.

Returns:

Messaging instance over this grid projection.

events

GridEvents events()

Gets events functionality over this grid projection. All operations on the returned GridEvents instance will only include nodes from this projection.

Returns:

Events instance over this grid projection.

forNodes

GridProjection forNodes(Collection<? extends GridNode> nodes)

Creates a grid projection over a given set of nodes.

Parameters:

nodes - Collection of nodes to create a projection from.

Returns:

Projection over provided grid nodes.

forNode

GridProjection forNode(GridNode node,
                     GridNode... nodes)

Creates a grid projection for the given node.

Parameters:

node - Node to get projection for.

nodes - Optional additional nodes to include into projection.

Returns:

Grid projection for the given node.

forOthers

GridProjection forOthers(GridNode node,
                       GridNode... nodes)

Creates a grid projection for nodes other than given nodes.

Parameters:

node - Node to exclude from new grid projection.

nodes - Optional additional nodes to exclude from projection.

Returns:

Projection that will contain all nodes that original projection contained excluding given nodes.

forOthers

GridProjection forOthers(GridProjection prj)

Creates a grid projection for nodes not included into given projection.

Parameters:

prj - Projection to exclude from new grid projection.

Returns:

Projection for nodes not included into given projection.

forNodeIds

GridProjection forNodeIds(Collection<UUID> ids)

Creates a grid projection over nodes with specified node IDs.

Parameters:

ids - Collection of node IDs.

Returns:

Projection over nodes with specified node IDs.

forNodeId

GridProjection forNodeId(UUID id,
                       UUID... ids)

Creates a grid projection for a node with specified ID.

Parameters:

id - Node ID to get projection for.

ids - Optional additional node IDs to include into projection.

Returns:

Projection over node with specified node ID.

forPredicate

GridProjection forPredicate(GridPredicate<GridNode> p)

Creates a grid projection which includes all nodes that pass the given predicate filter.

Parameters:

p - Predicate filter for nodes to include into this projection.

Returns:

Grid projection for nodes that passed the predicate filter.

forAttribute

GridProjection forAttribute(String name,
                          @Nullable
                          String val)

Creates projection for nodes containing given name and value specified in user attributes.

User attributes for every node are optional and can be specified in grid node configuration. See GridConfiguration.getUserAttributes() for more information.

Parameters:

name - Name of the attribute.

val - Optional attribute value to match.

Returns:

Grid projection for nodes containing specified attribute.

forCache

GridProjection forCache(String cacheName,
                      @Nullable
                      String... cacheNames)

Creates projection for all nodes that have cache with specified name running.

Parameters:

cacheName - Cache name.

cacheNames - Optional additional cache names to include into projection.

Returns:

Projection over nodes that have specified cache running.

forStreamer

GridProjection forStreamer(String streamerName,
                         @Nullable
                         String... streamerNames)

Creates projection for all nodes that have streamer with specified name running.

Parameters:

streamerName - Streamer name.

streamerNames - Optional additional streamer names to include into projection.

Returns:

Projection over nodes that have specified streamer running.

forRemotes

GridProjection forRemotes()

Gets grid projection consisting from the nodes in this projection excluding the local node.

Returns:

Grid projection consisting from the nodes in this projection excluding the local node, if any.

forHost

GridProjection forHost(GridNode node)

Gets grid projection consisting from the nodes in this projection residing on the same host as given node.

Parameters:

node - Node residing on the host for which projection is created.

Returns:

Projection for nodes residing on the same host as passed in node.

forDaemons

GridProjection forDaemons()

Gets projection consisting from the daemon nodes in this projection.

Daemon nodes are the usual grid nodes that participate in topology but not visible on the main APIs, i.e. they are not part of any projections. The only way to see daemon nodes is to use this method.

Daemon nodes are used primarily for management and monitoring functionality that is build on GridGain and needs to participate in the topology but also needs to be excluded from "normal" topology so that it won't participate in task execution or in-memory data grid storage.

Returns:

Grid projection consisting from the daemon nodes in this projection.

forRandom

GridProjection forRandom()

Creates grid projection with one random node from current projection.

Returns:

Grid projection with one random node from current projection.

nodes

Collection<GridNode> nodes()

Gets read-only collections of nodes in this projection.

Returns:

All nodes in this projection.

node

@Nullable
GridNode node(UUID nid)

Gets a node for given ID from this grid projection.

Parameters:

nid - Node ID.

Returns:

Node with given ID from this projection or null if such node does not exist in this projection.

node

@Nullable
GridNode node()

Gets first node from the list of nodes in this projection. This method is specifically useful for projection over one node only.

Returns:

First node from the list of nodes in this projection or null if projection is empty.

predicate

GridPredicate<GridNode> predicate()

Gets predicate that defines a subset of nodes for this projection.

Returns:

Predicate that defines a subset of nodes for this projection.

metrics

GridProjectionMetrics metrics()
                              throws GridException

Gets a metrics snapshot for this projection.

Returns:

Grid project metrics snapshot.

Throws:

GridException - If projection is empty.