diff --git a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/oai/OaiIterator.java b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/oai/OaiIterator.java
index 2392dee6a..df0722905 100644
--- a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/oai/OaiIterator.java
+++ b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/oai/OaiIterator.java
@@ -149,14 +149,14 @@ public class OaiIterator implements Iterator<String> {
 		try {
 			doc = reader.read(new StringReader(xml));
 		} catch (final DocumentException e) {
-			log.warn("Error parsing xml, I try to clean it: " + xml, e);
+			log.warn("Error parsing xml, I try to clean it. {}", e.getMessage());
 			final String cleaned = XmlCleaner.cleanAllEntities(xml);
 			try {
 				doc = reader.read(new StringReader(cleaned));
 			} catch (final DocumentException e1) {
 				final String resumptionToken = extractResumptionToken(xml);
 				if (resumptionToken == null) {
-					throw new CollectorException("Error parsing cleaned document:" + cleaned, e1);
+					throw new CollectorException("Error parsing cleaned document:\n" + cleaned, e1);
 				}
 				return resumptionToken;
 			}
diff --git a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/worker/CollectorWorkerApplication.java b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/worker/CollectorWorkerApplication.java
index 1d99689db..d89bcee54 100644
--- a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/worker/CollectorWorkerApplication.java
+++ b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/worker/CollectorWorkerApplication.java
@@ -19,16 +19,19 @@ import eu.dnetlib.dhp.collection.worker.utils.CollectorPluginFactory;
 import eu.dnetlib.dhp.collector.worker.model.ApiDescriptor;
 
 /**
- * DnetCollectortWorkerApplication is the main class responsible to start the Dnet Collection into HDFS. This module
- * will be executed on the hadoop cluster and taking in input some parameters that tells it which is the right collector
- * plugin to use and where store the data into HDFS path
+ * CollectorWorkerApplication is the main class responsible to start the metadata collection process, storing the outcomes
+ * into HDFS. This application will be executed on the hadoop cluster, where invoked in the context of the metadata collection
+ * oozie workflow, it will receive all the input parameters necessary to instantiate the specific collection plugin and the
+ * relative specific configurations
  *
- * @author Sandro La Bruzzo
+ * @author Sandro La Bruzzo, Claudio Atzori
  */
 public class CollectorWorkerApplication {
 
 	private static final Logger log = LoggerFactory.getLogger(CollectorWorkerApplication.class);
 
+	public static final String COLLECTOR_WORKER_ERRORS = "collectorWorker-errors";
+
 	/**
 	 * @param args
 	 */
@@ -60,7 +63,7 @@ public class CollectorWorkerApplication {
 		final CollectorWorker worker = new CollectorWorker(api, hdfsuri, hdfsPath);
 		CollectorPluginErrorLogList errors = worker.collect();
 
-		populateOOZIEEnv("collectorErrors", errors.toString());
+		populateOOZIEEnv(COLLECTOR_WORKER_ERRORS, errors.toString());
 
 	}
 
diff --git a/dhp-workflows/dhp-aggregation/src/main/resources/eu/dnetlib/dhp/collection/oozie_app/workflow.xml b/dhp-workflows/dhp-aggregation/src/main/resources/eu/dnetlib/dhp/collection/oozie_app/workflow.xml
index 2b2cf9dce..595613a2e 100644
--- a/dhp-workflows/dhp-aggregation/src/main/resources/eu/dnetlib/dhp/collection/oozie_app/workflow.xml
+++ b/dhp-workflows/dhp-aggregation/src/main/resources/eu/dnetlib/dhp/collection/oozie_app/workflow.xml
@@ -87,6 +87,7 @@
             <arg>--apidescriptor</arg><arg>${apiDescription}</arg>
             <arg>--namenode</arg><arg>${nameNode}</arg>
             <arg>--mdStoreVersion</arg><arg>${wf:actionData('StartTransaction')['mdStoreVersion']}</arg>
+            <capture-output/>
         </java>
         <ok to="GenerateNativeStoreSparkJob"/>
         <error to="FailCollection"/>
@@ -133,7 +134,6 @@
             <arg>--action</arg><arg>READ_UNLOCK</arg>
             <arg>--mdStoreManagerURI</arg><arg>${mdStoreManagerURI}</arg>
             <arg>--readMDStoreId</arg><arg>${wf:actionData('BeginRead')['mdStoreReadLockVersion']}</arg>
-            <capture-output/>
         </java>
         <ok to="CommitVersion"/>
         <error to="Kill"/>
@@ -165,7 +165,6 @@
             <arg>--action</arg><arg>READ_UNLOCK</arg>
             <arg>--mdStoreManagerURI</arg><arg>${mdStoreManagerURI}</arg>
             <arg>--readMDStoreId</arg><arg>${wf:actionData('BeginRead')['mdStoreReadLockVersion']}</arg>
-            <capture-output/>
         </java>
         <ok to="RollBack"/>
         <error to="Kill"/>