org.apache.giraph.partition

Interface MasterGraphPartitioner<I extends org.apache.hadoop.io.WritableComparable,V extends org.apache.hadoop.io.Writable,E extends org.apache.hadoop.io.Writable>

Type Parameters:

I - Vertex index value

V - Vertex value

E - Edge value

All Known Implementing Classes:

MasterGraphPartitionerImpl

public interface MasterGraphPartitioner<I extends org.apache.hadoop.io.WritableComparable,V extends org.apache.hadoop.io.Writable,E extends org.apache.hadoop.io.Writable>

Determines how to divide the graph into partitions, how to manipulate partitions and then how to assign those partitions to workers.

Method Summary

Modifier and Type	Method and Description
Collection<PartitionOwner>	createInitialPartitionOwners(Collection<WorkerInfo> availableWorkerInfos, int maxWorkers) Set some initial partition owners for the graph.
PartitionStats	createPartitionStats() Instantiate the PartitionStats implementation used to read the worker stats
Collection<PartitionOwner>	generateChangedPartitionOwners(Collection<PartitionStats> allPartitionStatsList, Collection<WorkerInfo> availableWorkers, int maxWorkers, long superstep) After the worker stats have been merged to a single list, the master can use this information to send commands to the workers for any Partition changes.
Collection<PartitionOwner>	getCurrentPartitionOwners() Get current partition owners at this time.
void	setPartitionOwners(Collection<PartitionOwner> partitionOwners) Sets partition owners for the graph.

Method Detail

createInitialPartitionOwners

Collection<PartitionOwner> createInitialPartitionOwners(Collection<WorkerInfo> availableWorkerInfos,
                                                        int maxWorkers)

Set some initial partition owners for the graph. Guaranteed to be called prior to the graph being loaded (initial or restart).

Parameters:

availableWorkerInfos - Workers available for partition assignment

maxWorkers - Maximum number of workers

Returns:

Collection of generated partition owners.

setPartitionOwners

void setPartitionOwners(Collection<PartitionOwner> partitionOwners)

Sets partition owners for the graph. Used then loading from checkpoint.

Parameters:

partitionOwners - assigned partition owners.

generateChangedPartitionOwners

Collection<PartitionOwner> generateChangedPartitionOwners(Collection<PartitionStats> allPartitionStatsList,
                                                          Collection<WorkerInfo> availableWorkers,
                                                          int maxWorkers,
                                                          long superstep)

After the worker stats have been merged to a single list, the master can use this information to send commands to the workers for any Partition changes. This protocol is specific to the MasterGraphPartitioner implementation.

Parameters:

allPartitionStatsList - All partition stats from all workers.

availableWorkers - Workers available for partition assignment

maxWorkers - Maximum number of workers

superstep - Partition owners will be set for this superstep

Returns:

Collection of PartitionOwner objects that changed from the previous superstep, empty list if no change.

getCurrentPartitionOwners

Collection<PartitionOwner> getCurrentPartitionOwners()

Get current partition owners at this time.

Returns:

Collection of current PartitionOwner objects

createPartitionStats

PartitionStats createPartitionStats()

Instantiate the PartitionStats implementation used to read the worker stats

Returns:

Instantiated PartitionStats object