com.sun.sgs.impl.service.nodemap
Interface NodeAssignPolicy

All Known Implementing Classes:

AbstractNodePolicy, LocalNodePolicy, RoundRobinPolicy

public interface NodeAssignPolicy

Interface for node assignment. The actual policy to be used is configurable in the node mapping server. A class implementing the NodeAssignPolicy interface must have a public constructor that takes the following argument:

• Properties

Field Summary

static long

SERVER_NODE An id representing the server node.

Method Summary

long	chooseNode(long requestingNode) Choose a node to assign an identity, or set of identities to.
long	chooseNode(long requestingNode, Identity id) Choose a node to assign an identity to.
void	nodeAvailable(long nodeId) Inform the policy that a node is now available.
void	nodeUnavailable(long nodeId) Inform the policy that a node is no longer available.
void	reset() Reset the policy, informing it that no nodes are available.

Field Detail

SERVER_NODE

static final long SERVER_NODE

An id representing the server node.

See Also:

Constant Field Values

Method Detail

chooseNode

long chooseNode(long requestingNode)
                throws NoNodesAvailableException

Choose a node to assign an identity, or set of identities to.

Parameters:

requestingNode - the id of the node making the request, or SERVER_NODE if the system is making the request

Returns:

the chosen node's id

Throws:

NoNodesAvailableException - if there are no live nodes to assign to

chooseNode

long chooseNode(long requestingNode,
                Identity id)
                throws NoNodesAvailableException

Choose a node to assign an identity to.

Parameters:

requestingNode - the id of the node making the request, or SERVER_NODE if the system is making the request

id - the identity which needs an assignment.

Returns:

the chosen node's id

Throws:

NoNodesAvailableException - if there are no live nodes to assign to

nodeAvailable

void nodeAvailable(long nodeId)

Inform the policy that a node is now available.

Parameters:

nodeId - the node ID

nodeUnavailable

void nodeUnavailable(long nodeId)

Inform the policy that a node is no longer available.

Parameters:

nodeId - the node ID

reset

void reset()

Reset the policy, informing it that no nodes are available.