BrBETA_dnet-hadoop/dhp-workflows/dhp-graph-provision/src/main/java/eu/dnetlib/dhp/oa/provision/AdjacencyListBuilderJob.java

123 lines
5.2 KiB
Java

package eu.dnetlib.dhp.oa.provision;
import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.common.HdfsSupport;
import eu.dnetlib.dhp.oa.provision.model.EntityRelEntity;
import eu.dnetlib.dhp.oa.provision.model.JoinedEntity;
import eu.dnetlib.dhp.oa.provision.model.Tuple2;
import eu.dnetlib.dhp.schema.common.ModelSupport;
import org.apache.commons.io.IOUtils;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.function.MapFunction;
import org.apache.spark.api.java.function.MapGroupsFunction;
import org.apache.spark.sql.Encoders;
import org.apache.spark.sql.SaveMode;
import org.apache.spark.sql.SparkSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import static eu.dnetlib.dhp.common.SparkSessionSupport.runWithSparkSession;
/**
* Joins the graph nodes by resolving the links of distance = 1 to create an adjacency list of linked objects.
* The operation considers all the entity types (publication, dataset, software, ORP, project, datasource, organization,
* and all the possible relationships (similarity links produced by the Dedup process are excluded).
*
* The operation is implemented by sequentially joining one entity type at time (E) with the relationships (R), and again
* by E, finally grouped by E.id;
*
* The workflow is organized in different parts aimed to to reduce the complexity of the operation
* 1) PrepareRelationsJob:
* only consider relationships that are not virtually deleted ($.dataInfo.deletedbyinference == false), each entity
* can be linked at most to 100 other objects
*
* 2) JoinRelationEntityByTargetJob:
* (phase 1): prepare tuples [relation - target entity] (R - T):
* for each entity type E_i
* map E_i as RelatedEntity T_i to simplify the model and extracting only the necessary information
* join (R.target = T_i.id)
* save the tuples (R_i, T_i)
* (phase 2):
* create the union of all the entity types E, hash by id
* read the tuples (R, T), hash by R.source
* join E.id = (R, T).source, where E becomes the Source Entity S
* save the tuples (S, R, T)
*
* 3) AdjacencyListBuilderJob:
* given the tuple (S - R - T) we need to group by S.id -> List [ R - T ], mapping the result as JoinedEntity
*
* 4) XmlConverterJob:
* convert the JoinedEntities as XML records
*/
public class AdjacencyListBuilderJob {
private static final Logger log = LoggerFactory.getLogger(AdjacencyListBuilderJob.class);
public static final int MAX_LINKS = 100;
public static void main(String[] args) throws Exception {
final ArgumentApplicationParser parser = new ArgumentApplicationParser(
IOUtils.toString(
AdjacencyListBuilderJob.class
.getResourceAsStream("/eu/dnetlib/dhp/oa/provision/input_params_build_adjacency_lists.json")));
parser.parseArgument(args);
Boolean isSparkSessionManaged = Optional
.ofNullable(parser.get("isSparkSessionManaged"))
.map(Boolean::valueOf)
.orElse(Boolean.TRUE);
log.info("isSparkSessionManaged: {}", isSparkSessionManaged);
String inputPath = parser.get("inputPath");
log.info("inputPath: {}", inputPath);
String outputPath = parser.get("outputPath");
log.info("outputPath: {}", outputPath);
SparkConf conf = new SparkConf();
conf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer");
conf.registerKryoClasses(ModelSupport.getOafModelClasses());
runWithSparkSession(conf, isSparkSessionManaged,
spark -> {
removeOutputDir(spark, outputPath);
createAdjacencyLists(spark, inputPath, outputPath);
});
}
private static void createAdjacencyLists(SparkSession spark, String inputPath, String outputPath) {
log.info("Reading joined entities from: {}", inputPath);
spark.read()
.load(inputPath)
.as(Encoders.bean(EntityRelEntity.class))
.groupByKey((MapFunction<EntityRelEntity, String>) value -> value.getEntity().getId(), Encoders.STRING())
.mapGroups((MapGroupsFunction<String, EntityRelEntity, JoinedEntity>) (key, values) -> {
JoinedEntity j = new JoinedEntity();
List<Tuple2> links = new ArrayList<>();
while (values.hasNext() && links.size() < MAX_LINKS) {
EntityRelEntity curr = values.next();
if (j.getEntity() == null) {
j.setEntity(curr.getEntity());
}
links.add(new Tuple2(curr.getRelation(), curr.getTarget()));
}
j.setLinks(links);
return j;
}, Encoders.bean(JoinedEntity.class))
.write()
.mode(SaveMode.Overwrite)
.parquet(outputPath);
}
private static void removeOutputDir(SparkSession spark, String path) {
HdfsSupport.remove(path, spark.sparkContext().hadoopConfiguration());
}
}