org.janusgraph.graphdb.database.idassigner.placement

Class SimpleBulkPlacementStrategy

java.lang.Object

org.janusgraph.graphdb.database.idassigner.placement.SimpleBulkPlacementStrategy

All Implemented Interfaces:

IDPlacementStrategy

Direct Known Subclasses:

PropertyPlacementStrategy

public class SimpleBulkPlacementStrategy
extends Object
implements IDPlacementStrategy

A id placement strategy that assigns all vertices created in a transaction to the same partition id. The partition id is selected randomly from a set of partition ids that are retrieved upon initialization. The number of partition ids to choose from is configurable.

Author:

Matthias Broecheler (me@matthiasb.com)

Field Summary

Fields

Modifier and Type	Field and Description
static ConfigOption<Integer>	CONCURRENT_PARTITIONS
static int	PARTITION_FINDING_ATTEMPTS

Constructor Summary

Constructors

Constructor and Description
SimpleBulkPlacementStrategy(Configuration config)
SimpleBulkPlacementStrategy(int concurrentPartitions)

Method Summary

Modifier and Type	Method and Description
void	exhaustedPartition(int partitionID) Called when there are no more idAuthorities left in the given partition.
int	getPartition(InternalElement element) Individually assigns an id to the given vertex or relation.
void	getPartitions(Map<InternalVertex,PartitionAssignment> vertices) Bulk assignment of idAuthorities to vertices.
void	injectIDManager(IDManager idManager) After construction, the IDManager used by this graph instance is injected into this IDPlacementStrategy so that the id pattern of vertices can be inspected.
boolean	isExhaustedPartition(int partitionID)
void	setLocalPartitionBounds(List<PartitionIDRange> localPartitionIdRanges) If JanusGraph is embedded, this method is used to indicate to the placement strategy which part of the partition id space is hosted locally so that vertex and edge placements can be made accordingly (i.e. preferring to assign partitions in the local ranges so that the data is hosted locally which is often faster).
boolean	supportsBulkPlacement() Whether this placement strategy supports bulk placement.

Methods inherited from class java.lang.Object

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

Field Detail

CONCURRENT_PARTITIONS

public static final ConfigOption<Integer> CONCURRENT_PARTITIONS

PARTITION_FINDING_ATTEMPTS

public static final int PARTITION_FINDING_ATTEMPTS

See Also:

Constant Field Values

Constructor Detail

SimpleBulkPlacementStrategy

public SimpleBulkPlacementStrategy(int concurrentPartitions)

SimpleBulkPlacementStrategy

public SimpleBulkPlacementStrategy(Configuration config)

Method Detail

injectIDManager

public void injectIDManager(IDManager idManager)

Description copied from interface: IDPlacementStrategy

After construction, the IDManager used by this graph instance is injected into this IDPlacementStrategy so that the id pattern of vertices can be inspected. This method is guaranteed to be called before any partition assignments are made.

Specified by:

injectIDManager in interface IDPlacementStrategy

getPartition

public int getPartition(InternalElement element)

Description copied from interface: IDPlacementStrategy

Individually assigns an id to the given vertex or relation.

Specified by:

getPartition in interface IDPlacementStrategy

Parameters:

element - Vertex or relation to assign id to.

Returns:

getPartitions

public void getPartitions(Map<InternalVertex,PartitionAssignment> vertices)

Description copied from interface: IDPlacementStrategy

Bulk assignment of idAuthorities to vertices.

It is expected that the passed in map contains the partition assignment after this method returns. Any initial values in the map are meaningless and to be ignored.

This is an optional operation. Check with IDPlacementStrategy.supportsBulkPlacement() first.

Specified by:

getPartitions in interface IDPlacementStrategy

Parameters:

vertices - Map containing all vertices and their partition placement.

supportsBulkPlacement

public boolean supportsBulkPlacement()

Description copied from interface: IDPlacementStrategy

Whether this placement strategy supports bulk placement. If not, then IDPlacementStrategy.getPartitions(java.util.Map) will throw UnsupportedOperationException

Specified by:

supportsBulkPlacement in interface IDPlacementStrategy

Returns:

setLocalPartitionBounds

public void setLocalPartitionBounds(List<PartitionIDRange> localPartitionIdRanges)

Description copied from interface: IDPlacementStrategy

If JanusGraph is embedded, this method is used to indicate to the placement strategy which part of the partition id space is hosted locally so that vertex and edge placements can be made accordingly (i.e. preferring to assign partitions in the local ranges so that the data is hosted locally which is often faster).

This method can be called at any time while JanusGraph is running. It is typically called right after construction and when the id space is redistributed.

Depending on the storage backend one or multiple ranges of partition ids may be given. However, this list is never empty.

Specified by:

setLocalPartitionBounds in interface IDPlacementStrategy

Parameters:

localPartitionIdRanges - List of PartitionIDRanges corresponding to the locally hosted partitions

isExhaustedPartition

public boolean isExhaustedPartition(int partitionID)

exhaustedPartition

public void exhaustedPartition(int partitionID)

Description copied from interface: IDPlacementStrategy

Called when there are no more idAuthorities left in the given partition. It is expected that the placement strategy will no longer use said partition in its placement suggestions.

Specified by:

exhaustedPartition in interface IDPlacementStrategy

Parameters:

partitionID - Id of the partition that has been exhausted.