org.gridgain.grid.events

Class GridDiscoveryEvent

java.lang.Object

org.gridgain.grid.events.GridEventAdapter

org.gridgain.grid.events.GridDiscoveryEvent

All Implemented Interfaces:

Serializable, Comparable<GridEvent>, GridEvent

public class GridDiscoveryEvent
extends GridEventAdapter

Grid discovery event.

Grid events are used for notification about what happens within the grid. Note that by design GridGain keeps all events generated on the local node locally and it provides APIs for performing a distributed queries across multiple nodes:

• GridEvents.remoteQuery(GridPredicate, long, int...) - asynchronously querying events occurred on the nodes specified, including remote nodes.
• GridEvents.localQuery(GridPredicate, int...) - querying only local events stored on this local node.
• GridEvents.localListen(GridPredicate, int...) - listening to local grid events (events from remote nodes not included).

User can also wait for events using method GridEvents.waitForLocal(GridPredicate, int...).

Events and Performance

Note that by default all events in GridGain are enabled and therefore generated and stored by whatever event storage SPI is configured. GridGain can and often does generate thousands events per seconds under the load and therefore it creates a significant additional load on the system. If these events are not needed by the application this load is unnecessary and leads to significant performance degradation.

It is highly recommended to enable only those events that your application logic requires by using GridConfiguration.getIncludeEventTypes() method in GridGain configuration. Note that certain events are required for GridGain's internal operations and such events will still be generated but not stored by event storage SPI if they are disabled in GridGain configuration.

See Also:

GridEventType.EVT_NODE_METRICS_UPDATED, GridEventType.EVT_NODE_FAILED, GridEventType.EVT_NODE_JOINED, GridEventType.EVT_NODE_LEFT, GridEventType.EVT_NODE_RECONNECTED, GridEventType.EVT_NODE_SEGMENTED, GridEventType.EVTS_DISCOVERY_ALL, GridEventType.EVTS_DISCOVERY, Serialized Form

Constructor Summary

Constructors

Constructor and Description
GridDiscoveryEvent() No-arg constructor.
GridDiscoveryEvent(GridNode node, String msg, int type) Creates new discovery event with given parameters.
GridDiscoveryEvent(GridNode node, String msg, int type, GridNode evtNode) Creates new discovery event with given parameters.

Method Summary

Methods

Modifier and Type	Method and Description
GridNode	eventNode() Gets node that caused this event to be generated.
void	eventNode(GridNode evtNode) Sets node this event is referring to.
String	shortDisplay() Gets a shortened version of toString() result.
Collection<GridNode>	topologyNodes() Gets topology nodes from topology snapshot.
void	topologySnapshot(long topVer, Collection<GridNode> topSnapshot) Sets the topology snapshot.
long	topologyVersion() Gets topology version if this event is raised on topology change and configured discovery SPI implementation supports topology versioning.
String	toString()

Methods inherited from class org.gridgain.grid.events.GridEventAdapter

compareTo, equals, hashCode, id, localOrder, message, message, name, node, node, timestamp, type, type

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

GridDiscoveryEvent

public GridDiscoveryEvent()

No-arg constructor.

GridDiscoveryEvent

public GridDiscoveryEvent(GridNode node,
                  String msg,
                  int type,
                  GridNode evtNode)

Creates new discovery event with given parameters.

Parameters:

node - Local node.

msg - Optional event message.

type - Event type.

evtNode - Node that caused this event to be generated.

GridDiscoveryEvent

public GridDiscoveryEvent(GridNode node,
                  String msg,
                  int type)

Creates new discovery event with given parameters.

Parameters:

node - Local node.

msg - Optional event message.

type - Event type.

Method Detail

shortDisplay

public String shortDisplay()

Gets a shortened version of toString() result. Suitable for humans to read.

Specified by:

shortDisplay in interface GridEvent

Overrides:

shortDisplay in class GridEventAdapter

Returns:

Shortened version of toString() result.

eventNode

public void eventNode(GridNode evtNode)

Sets node this event is referring to.

Parameters:

evtNode - Event node.

eventNode

public GridNode eventNode()

Gets node that caused this event to be generated. It is potentially different from the node on which this event was recorded. For example, node A locally recorded the event that a remote node B joined the topology. In this case this method will return ID of B.

Returns:

Event node ID.

topologyVersion

public long topologyVersion()

Gets topology version if this event is raised on topology change and configured discovery SPI implementation supports topology versioning.

Returns:

Topology version or 0 if configured discovery SPI implementation does not support versioning.

topologyNodes

public Collection<GridNode> topologyNodes()

Gets topology nodes from topology snapshot. If SPI implementation does not support versioning, the best effort snapshot will be captured.

Returns:

Topology snapshot.

topologySnapshot

public void topologySnapshot(long topVer,
                    Collection<GridNode> topSnapshot)

Sets the topology snapshot.

Parameters:

topVer - Topology version.

topSnapshot - Topology snapshot.

toString

public String toString()

Overrides:

toString in class GridEventAdapter