Spark Operations

These Operations are part of the Spark library. They are only available if they have been specifically enabled and are only supported by the Accumulo store. They are enabled by registering the Spark operations and their handlers with your store. You need to add the following to your store properties file:

gaffer.store.operation.declarations=sparkAccumuloOperationsDeclarations.json

There is an option to read the RFiles directly rather than the usual approach of obtaining them from Accumulo's tablet servers. This requires the Hadoop user, running the Spark job, to have read access to the RFiles in the Accumulo tablet. Note, however, that data which has not been minor compacted will not be read if this option is used. This functionality is enabled using the option: gaffer.accumulo.spark.directrdd.use_rfile_reader=true.

This directed graph is used in all the examples on this page:

graph TD
  1(1, count=3) -- count=3 --> 2
  1 -- count=1 --> 4
  2(2, count=1) -- count=2 --> 3
  2 -- count=1 --> 4(4, count=1)
  2 -- count=1 --> 5(5, count=3)
  3(3, count=2) -- count=4 --> 4

GetDataFrameOfElements

Operation that returns an Apache Spark DataFrame consisting of Elements converted to Rows, fields are ordered according to the ordering of the groups in the view, with Entities first, followed by Edges. Javadoc

Example getting data frame of elements with entity group

JavaJSON

final GetDataFrameOfElements operation = new GetDataFrameOfElements.Builder()
        .view(new View.Builder()
                .entity("entity")
                .build())
        .build();

{
  "class" : "GetDataFrameOfElements",
  "view" : {
    "entities" : {
      "entity" : { }
    }
  }
}

Results:

group	vertex	count
entity	1	3
entity	2	1
entity	3	2
entity	4	1
entity	5	3

Using filter:

df.filter("vertex = 1 OR vertex = 2").show();

The results are:

group	vertex	count
entity	1	3
entity	2	1

Using filter:

df.filter("count > 1").show();

The results are:

group	vertex	count
entity	1	3
entity	3	2
entity	5	3

Example getting data frame of elements with edge group

JavaJSON

final GetDataFrameOfElements operation = new GetDataFrameOfElements.Builder()
        .view(new View.Builder()
                .edge("edge")
                .build())
        .build();

{
  "class" : "GetDataFrameOfElements",
  "view" : {
    "edges" : {
      "edge" : { }
    }
  }
}

Results:

group	src	dst	directed	matchedVertex	count
edge	1	2	true	null	3
edge	1	4	true	null	1
edge	2	3	true	null	2
edge	2	4	true	null	1
edge	2	5	true	null	1
edge	3	4	true	null	4

Using filter:

df.filter("src = 1 OR src = 3").show();

The results are:

group	src	dst	directed	matchedVertex	count
edge	1	2	true	null	3
edge	1	4	true	null	1
edge	3	4	true	null	4

Using filter:

df.filter("count > 1").show();

The results are:

group	src	dst	directed	matchedVertex	count
edge	1	2	true	null	3
edge	2	3	true	null	2
edge	3	4	true	null	4

GetGraphFrameOfElements

Operation which returns an Apache Spark GraphFrame consisting of Elements converted to rows. Javadoc

Example getting graph frame of elements

JavaJSON

final GetGraphFrameOfElements operation = new GetGraphFrameOfElements.Builder()
        .view(new View.Builder()
                .entity("entity")
                .edge("edge")
                .build())
        .build();

{
  "class" : "GetGraphFrameOfElements",
  "view" : {
    "edges" : {
      "edge" : { }
    },
    "entities" : {
      "entity" : { }
    }
  }
}

Then with the graphFrame result you can execute for example:

graphFrame.vertices().filter("vertex = 1 OR vertex = 2").showString(100, 20)

and the results are:

matchedVertex	directed	id	dst	src	count	group
null	null	1	null	null	null	null
null	null	2	null	null	null	null
null	null	1	null	null	3	entity
null	null	2	null	null	1	entity

Or you can inspect the edges:

graphFrame.edges().filter("count > 1").showString(100, 20)

and the results are:

group	vertex	count	src	dst	directed	matchedVertex	id
edge	null	3	1	2	true	null	1
edge	null	2	2	3	true	null	3
edge	null	4	3	4	true	null	6

GraphFrames also include operations such as PageRank.

GetJavaRDDOfAllElements

Operation which retrieves all Elements, and returns them inside a JavaRDD. Javadoc

Example getting JavaRDD of all elements

JavaJSON

final GetJavaRDDOfAllElements operation = new GetJavaRDDOfAllElements();

{
  "class" : "GetJavaRDDOfAllElements"
}

Results:

Java

Entity[vertex=1,group=entity,properties=Properties[count=<java.lang.Integer>3]]
Edge[source=1,destination=2,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>3]]
Edge[source=1,destination=4,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>1]]
Entity[vertex=2,group=entity,properties=Properties[count=<java.lang.Integer>1]]
Edge[source=2,destination=3,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>2]]
Edge[source=2,destination=4,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>1]]
Edge[source=2,destination=5,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>1]]
Entity[vertex=3,group=entity,properties=Properties[count=<java.lang.Integer>2]]
Edge[source=3,destination=4,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>4]]
Entity[vertex=4,group=entity,properties=Properties[count=<java.lang.Integer>1]]
Entity[vertex=5,group=entity,properties=Properties[count=<java.lang.Integer>3]]

Example getting JavaRDD of all elements returning edges only

JavaJSON

final GetJavaRDDOfAllElements operation = new GetJavaRDDOfAllElements.Builder()
        .view(new View.Builder()
                .edge("edge")
                .build())
        .build();

{
  "class" : "GetJavaRDDOfAllElements",
  "view" : {
    "edges" : {
      "edge" : { }
    }
  }
}

Results:

Java

Edge[source=1,destination=2,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>3]]
Edge[source=1,destination=4,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>1]]
Edge[source=2,destination=3,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>2]]
Edge[source=2,destination=4,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>1]]
Edge[source=2,destination=5,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>1]]
Edge[source=3,destination=4,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>4]]

GetJavaRDDOfElements

Operation which retrieves all the Elements for input seeds, and returns them inside a JavaRDD. Javadoc

Example getting JavaRDD of elements with seeds

JavaJSON

final GetJavaRDDOfElements operation = new GetJavaRDDOfElements.Builder()
        .input(new EdgeSeed(1, 2, true), new EdgeSeed(2, 3, true))
        .build();

{
  "class" : "GetJavaRDDOfElements",
  "input" : [ {
    "class" : "EdgeSeed",
    "source" : 1,
    "destination" : 2,
    "matchedVertex" : "SOURCE",
    "directedType" : "DIRECTED"
  }, {
    "class" : "EdgeSeed",
    "source" : 2,
    "destination" : 3,
    "matchedVertex" : "SOURCE",
    "directedType" : "DIRECTED"
  } ]
}

Results:

Java

Entity[vertex=1,group=entity,properties=Properties[count=<java.lang.Integer>3]]
Edge[source=1,destination=2,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>3]]
Entity[vertex=2,group=entity,properties=Properties[count=<java.lang.Integer>1]]
Edge[source=2,destination=3,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>2]]
Entity[vertex=3,group=entity,properties=Properties[count=<java.lang.Integer>2]]

Example getting JavaRDD of elements with Hadoop conf

JavaJSON

final Configuration conf = new Configuration();
conf.set("AN_OPTION", "A_VALUE");

final String encodedConf;
try {
    encodedConf = AbstractGetRDDHandler.convertConfigurationToString(conf);
} catch (final IOException e) {
    throw new RuntimeException("Unable to convert conf to string", e);
}

final GetJavaRDDOfElements operation = new GetJavaRDDOfElements.Builder()
        .input(new EdgeSeed(1, 2, true), new EdgeSeed(2, 3, true))
        .option(AbstractGetRDDHandler.HADOOP_CONFIGURATION_KEY, encodedConf)
        .build();

{
  "class" : "GetJavaRDDOfElements",
  "input" : [ {
    "class" : "EdgeSeed",
    "source" : 1,
    "destination" : 2,
    "matchedVertex" : "SOURCE",
    "directedType" : "DIRECTED"
  }, {
    "class" : "EdgeSeed",
    "source" : 2,
    "destination" : 3,
    "matchedVertex" : "SOURCE",
    "directedType" : "DIRECTED"
  } ],
  "options" : {
    "Hadoop_Configuration_Key" : "config removed for readability"
  }
}

Example getting JavaRDD of elements with seeds, returning edges only

JavaJSON

final GetJavaRDDOfElements operation = new GetJavaRDDOfElements.Builder()
        .input(new EdgeSeed(1, 2, true), new EdgeSeed(2, 3, true))
        .view(new View.Builder()
                .edge("edge")
                .build())
        .build();

{
  "class" : "GetJavaRDDOfElements",
  "input" : [ {
    "class" : "EdgeSeed",
    "source" : 1,
    "destination" : 2,
    "matchedVertex" : "SOURCE",
    "directedType" : "DIRECTED"
  }, {
    "class" : "EdgeSeed",
    "source" : 2,
    "destination" : 3,
    "matchedVertex" : "SOURCE",
    "directedType" : "DIRECTED"
  } ],
  "view" : {
    "edges" : {
      "edge" : { }
    }
  }
}

Results:

Java

Edge[source=1,destination=2,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>3]]
Edge[source=2,destination=3,directed=true,group=edge,properties=Properties[count=<java.lang.Integer>2]]