org.apache.ignite.ml.dataset.impl.cache.util

Class DatasetAffinityFunctionWrapper

java.lang.Object

org.apache.ignite.ml.dataset.impl.cache.util.DatasetAffinityFunctionWrapper

All Implemented Interfaces:

Serializable, AffinityFunction

public class DatasetAffinityFunctionWrapper
extends Object
implements AffinityFunction

Affinity function wrapper that uses key as a partition index and delegates all other functions to specified delegate.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
DatasetAffinityFunctionWrapper(AffinityFunction delegate) Constructs a new instance of affinity function wrapper.

Method Summary

Modifier and Type	Method and Description
List<List<ClusterNode>>	assignPartitions(AffinityFunctionContext affCtx) Gets affinity nodes for a partition.
int	partition(Object key) Returns key as a partition index.
int	partitions() Gets total number of partitions available.
void	removeNode(UUID nodeId) Removes node from affinity.
void	reset() Resets cache affinity to its initial state.

Methods inherited from class java.lang.Object

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

Constructor Detail

DatasetAffinityFunctionWrapper

public DatasetAffinityFunctionWrapper(AffinityFunction delegate)

Constructs a new instance of affinity function wrapper.

Parameters:

delegate - Affinity function which actually performs all methods except partition().

Method Detail

reset

public void reset()

Resets cache affinity to its initial state. This method will be called by the system any time the affinity has been sent to remote node where it has to be reinitialized. If your implementation of affinity function has no initialization logic, leave this method empty.

Specified by:

reset in interface AffinityFunction

partitions

public int partitions()

Gets total number of partitions available. All caches should always provide correct partition count which should be the same on all participating nodes. Note that partitions should always be numbered from 0 inclusively to N exclusively without any gaps.

Specified by:

partitions in interface AffinityFunction

Returns:

Total partition count.

partition

public int partition(Object key)

Returns key as a partition index.

Specified by:

partition in interface AffinityFunction

Parameters:

key - Partition index.

Returns:

Partition index.

assignPartitions

public List<List<ClusterNode>> assignPartitions(AffinityFunctionContext affCtx)

Gets affinity nodes for a partition. In case of replicated cache, all returned nodes are updated in the same manner. In case of partitioned cache, the returned list should contain only the primary and back up nodes with primary node being always first.

Note that partitioned affinity must obey the following contract: given that node N is primary for some key K, if any other node(s) leave grid and no node joins grid, node N will remain primary for key K.

Specified by:

assignPartitions in interface AffinityFunction

Parameters:

affCtx - Affinity function context. Will provide all required information to calculate new partition assignments.

Returns:

Unmodifiable list indexed by partition number. Each element of array is a collection in which first node is a primary node and other nodes are backup nodes.

removeNode

public void removeNode(UUID nodeId)

Removes node from affinity. This method is called when it is safe to remove left node from affinity mapping.

Specified by:

removeNode in interface AffinityFunction

Parameters:

nodeId - ID of node to remove.