org.apache.tinkerpop.gremlin.process.computer

Interface GraphComputer

public interface GraphComputer

The GraphComputer is responsible for the execution of a VertexProgram and then a set of MapReduce jobs over the vertices in the Graph. It is up to the GraphComputer implementation to determine the appropriate memory structures given the computing substrate.

Author:

Marko A. Rodriguez (http://markorodriguez.com), Matthias Broecheler (me@matthiasb.com)

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	GraphComputer.Exceptions
static interface	GraphComputer.Features
static class	GraphComputer.Persist
static class	GraphComputer.ResultGraph

Method Summary

Modifier and Type	Method and Description
default GraphComputer	configure(String key, Object value) Set an arbitrary configuration key/value for the underlying Configuration in the GraphComputer.
GraphComputer	edges(Traversal<Vertex,Edge> edgeFilter) Add a filter that will limit which edges of the vertices are loaded from the graph source.
default GraphComputer.Features	features()
GraphComputer	mapReduce(MapReduce mapReduce) Add a MapReduce job to the set of MapReduce jobs to be executed by the GraphComputer.
GraphComputer	persist(GraphComputer.Persist persist) Set the GraphComputer.Persist level of the computation.
GraphComputer	program(VertexProgram vertexProgram) Set the VertexProgram to be executed by the GraphComputer.
GraphComputer	result(GraphComputer.ResultGraph resultGraph) Set the GraphComputer.ResultGraph of the computation.
Future<ComputerResult>	submit() Submit the VertexProgram and the set of MapReduce jobs for execution by the GraphComputer.
GraphComputer	vertices(Traversal<Vertex,Vertex> vertexFilter) Add a filter that will limit which vertices are loaded from the graph source.
GraphComputer	workers(int workers) Set the desired number of workers to execute the VertexProgram and MapReduce jobs.

Method Detail

result

GraphComputer result(GraphComputer.ResultGraph resultGraph)

Set the GraphComputer.ResultGraph of the computation. If this is not set explicitly by the user, then the VertexProgram can choose the most efficient result for its intended use. If there is no declared vertex program, then the GraphComputer defaults to GraphComputer.ResultGraph.ORIGINAL.

Parameters:

resultGraph - the type of graph to be returned by ComputerResult.graph()

Returns:

the updated GraphComputer with newly set result graph

persist

GraphComputer persist(GraphComputer.Persist persist)

Set the GraphComputer.Persist level of the computation. If this is not set explicitly by the user, then the\ VertexProgram can choose the most efficient persist for the its intended use. If there is no declared vertex program, then the GraphComputer defaults to GraphComputer.Persist.NOTHING.

Parameters:

persist - the persistence level of the resultant computation

Returns:

the updated GraphComputer with newly set persist

program

GraphComputer program(VertexProgram vertexProgram)

Set the VertexProgram to be executed by the GraphComputer. There can only be one VertexProgram for the GraphComputer.

Parameters:

vertexProgram - the VertexProgram to be executed

Returns:

the updated GraphComputer with newly set VertexProgram

mapReduce

GraphComputer mapReduce(MapReduce mapReduce)

Add a MapReduce job to the set of MapReduce jobs to be executed by the GraphComputer. There can be any number of MapReduce jobs.

Parameters:

mapReduce - the MapReduce job to add to the computation

Returns:

the updated GraphComputer with newly added MapReduce job

workers

GraphComputer workers(int workers)

Set the desired number of workers to execute the VertexProgram and MapReduce jobs. This is a recommendation to the underlying GraphComputer implementation and is allowed to deviate accordingly by the implementation.

Parameters:

workers - the number of workers to execute the submission

Returns:

the updated GraphComputer with newly set worker count

vertices

GraphComputer vertices(Traversal<Vertex,Vertex> vertexFilter)
                throws IllegalArgumentException

Add a filter that will limit which vertices are loaded from the graph source. The provided Traversal can only check the vertex, its vertex properties, and the vertex property properties. The loaded graph will only have those vertices that pass through the provided filter.

Parameters:

vertexFilter - the traversal to verify whether or not to load the current vertex

Returns:

the updated GraphComputer with newly set vertex filter

Throws:

IllegalArgumentException - if the provided traversal attempts to access vertex edges

edges

GraphComputer edges(Traversal<Vertex,Edge> edgeFilter)
             throws IllegalArgumentException

Add a filter that will limit which edges of the vertices are loaded from the graph source. The provided Traversal can only check the local star graph of the vertex and thus, can not access properties/labels of the adjacent vertices. The vertices of the loaded graph will only have those edges that pass through the provided filter.

Parameters:

edgeFilter - the traversal that determines which edges are loaded for each vertex

Returns:

the updated GraphComputer with newly set edge filter

Throws:

IllegalArgumentException - if the provided traversal attempts to access adjacent vertices

configure

default GraphComputer configure(String key,
                                Object value)

Set an arbitrary configuration key/value for the underlying Configuration in the GraphComputer. Typically, the other fluent methods in GraphComputer should be used to configure the computation. However, for some custom configuration in the underlying engine, this method should be used. Different GraphComputer implementations will have different key/values and thus, parameters placed here are generally not universal to all GraphComputer implementations. The default implementation simply does nothing and returns the GraphComputer unchanged.

Parameters:

key - the key of the configuration

value - the value of the configuration

Returns:

the updated GraphComputer with newly set key/value configuration

submit

Future<ComputerResult> submit()

Submit the VertexProgram and the set of MapReduce jobs for execution by the GraphComputer.

Returns:

a Future denoting a reference to the asynchronous computation and where to get the DefaultComputerResult when its is complete.

features

default GraphComputer.Features features()