diff --git a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step2/GenerateEntitiesApplication.java b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step2/GenerateEntitiesApplication.java
index 5627a720b..775e5e7d8 100644
--- a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step2/GenerateEntitiesApplication.java
+++ b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step2/GenerateEntitiesApplication.java
@@ -53,18 +53,20 @@ public class GenerateEntitiesApplication {
 		final String dbUser = parser.get("postgresUser");
 		final String dbPassword = parser.get("postgresPassword");
 
-		final SparkSession spark = SparkSession
+		final Map<String, String> code2name = loadClassNames(dbUrl, dbUser, dbPassword);
+
+		try (final SparkSession spark = newSparkSession(parser); final JavaSparkContext sc = new JavaSparkContext(spark.sparkContext())) {
+			final List<String> existingSourcePaths = Arrays.stream(sourcePaths.split(",")).filter(p -> exists(sc, p)).collect(Collectors.toList());
+			generateEntities(sc, code2name, existingSourcePaths, targetPath);
+		}
+	}
+
+	private static SparkSession newSparkSession(final ArgumentApplicationParser parser) {
+		return SparkSession
 				.builder()
 				.appName(GenerateEntitiesApplication.class.getSimpleName())
 				.master(parser.get("master"))
 				.getOrCreate();
-
-		final Map<String, String> code2name = loadClassNames(dbUrl, dbUser, dbPassword);
-
-		try (final JavaSparkContext sc = new JavaSparkContext(spark.sparkContext())) {
-			final List<String> existingSourcePaths = Arrays.stream(sourcePaths.split(",")).filter(p -> exists(sc, p)).collect(Collectors.toList());
-			generateEntities(sc, code2name, existingSourcePaths, targetPath);
-		}
 	}
 
 	private static void generateEntities(final JavaSparkContext sc,
@@ -96,7 +98,7 @@ public class GenerateEntitiesApplication {
 		case "native_oaf":
 			return new OafToOafMapper(code2name).processMdRecord(s);
 		case "native_odf":
-			return new OafToOafMapper(code2name).processMdRecord(s);
+			return new OdfToOafMapper(code2name).processMdRecord(s);
 		case "datasource":
 			return Arrays.asList(convertFromJson(s, Datasource.class));
 		case "organization":
diff --git a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step3/DispatchEntitiesApplication.java b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step3/DispatchEntitiesApplication.java
index 222828a49..4f10068e7 100644
--- a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step3/DispatchEntitiesApplication.java
+++ b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/step3/DispatchEntitiesApplication.java
@@ -28,13 +28,7 @@ public class DispatchEntitiesApplication {
 						.getResourceAsStream("/eu/dnetlib/dhp/migration/dispatch_entities_parameters.json")));
 		parser.parseArgument(args);
 
-		final SparkSession spark = SparkSession
-				.builder()
-				.appName(DispatchEntitiesApplication.class.getSimpleName())
-				.master(parser.get("master"))
-				.getOrCreate();
-
-		try (final JavaSparkContext sc = new JavaSparkContext(spark.sparkContext())) {
+		try (final SparkSession spark = newSparkSession(parser); final JavaSparkContext sc = new JavaSparkContext(spark.sparkContext())) {
 
 			final String sourcePath = parser.get("sourcePath");
 			final String targetPath = parser.get("graphRawPath");
@@ -50,6 +44,14 @@ public class DispatchEntitiesApplication {
 		}
 	}
 
+	private static SparkSession newSparkSession(final ArgumentApplicationParser parser) {
+		return SparkSession
+				.builder()
+				.appName(DispatchEntitiesApplication.class.getSimpleName())
+				.master(parser.get("master"))
+				.getOrCreate();
+	}
+
 	private static void processEntity(final JavaSparkContext sc, final Class<?> clazz, final String sourcePath, final String targetPath) {
 		final String type = clazz.getSimpleName().toLowerCase();
 
diff --git a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/utils/DbClient.java b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/utils/DbClient.java
index 43270e452..8e9784346 100644
--- a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/utils/DbClient.java
+++ b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/migration/utils/DbClient.java
@@ -28,8 +28,8 @@ public class DbClient implements Closeable {
 					StringUtils.isNoneBlank(login, password) ? DriverManager.getConnection(address, login, password) : DriverManager.getConnection(address);
 			this.connection.setAutoCommit(false);
 		} catch (final Exception e) {
-			log.error(e.getClass().getName() + ": " + e.getMessage());
-			throw new RuntimeException(e);
+			log.error("Connection to postgresDB failed");
+			throw new RuntimeException("Connection to postgresDB failed", e);
 		}
 		log.info("Opened database successfully");
 	}
@@ -44,10 +44,12 @@ public class DbClient implements Closeable {
 					consumer.accept(rs);
 				}
 			} catch (final SQLException e) {
-				throw new RuntimeException(e);
+				log.error("Error executing sql query: " + sql, e);
+				throw new RuntimeException("Error executing sql query", e);
 			}
 		} catch (final SQLException e1) {
-			throw new RuntimeException(e1);
+			log.error("Error preparing sql statement", e1);
+			throw new RuntimeException("Error preparing sql statement", e1);
 		}
 	}