diff --git a/README.md b/README.md
index 37cfa1a..6c95a19 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
-# UrlsController [![Build Status](https://jenkins-dnet.d4science.org/buildStatus/icon?job=UrlsController)](https://jenkins-dnet.d4science.org/job/UrlsController/)
+# UrlsController
+## [![Jenkins build status](https://jenkins-dnet.d4science.org/buildStatus/icon?job=UrlsController)](https://jenkins-dnet.d4science.org/job/UrlsController/)
 
 The Controller's Application receives requests coming from the [**Workers**](https://code-repo.d4science.org/lsmyrnaios/UrlsWorker) (deployed on the cloud), constructs an assignments-list with data received from a database and returns the list to the workers.<br>
 Then, it receives the "WorkerReports", it requests the full-texts from the workers, in batches, and uploads them on the S3-Object-Store. Finally, it writes the related reports, along with the updated file-locations into the database.<br> 
diff --git a/src/main/java/eu/openaire/urls_controller/controllers/ShutdownController.java b/src/main/java/eu/openaire/urls_controller/controllers/ShutdownController.java
index 11b3c62..dedcc77 100644
--- a/src/main/java/eu/openaire/urls_controller/controllers/ShutdownController.java
+++ b/src/main/java/eu/openaire/urls_controller/controllers/ShutdownController.java
@@ -136,7 +136,8 @@ public class ShutdownController {
     @PostMapping("workerShutdownReport")
     public ResponseEntity<?> workerShutdownReport(@RequestParam String workerId, HttpServletRequest request)
     {
-        String initMsg = "Received a \"workerShutdownReport\" from worker: \"" + workerId + "\".";
+        String remoteAddr = GenericUtils.getRequestorAddress(request);
+        String initMsg = "Received a \"workerShutdownReport\" from worker: \"" + workerId + "\" [IP: " + remoteAddr + "].";
         WorkerInfo workerInfo = UrlsController.workersInfoMap.get(workerId);
         if ( workerInfo == null ) {
             String errorMsg = "The worker with id \"" + workerId + "\" has not participated in the PDF-Aggregation-Service!";
@@ -144,9 +145,8 @@ public class ShutdownController {
             return ResponseEntity.badRequest().body(errorMsg);
         }
 
-        String remoteAddr = GenericUtils.getRequestorAddress(request);
         if ( ! remoteAddr.equals(workerInfo.getWorkerIP()) ) {
-            logger.error(initMsg + " The request came from another IP: " + remoteAddr + " | while this worker was registered with this IP: " + workerInfo.getWorkerIP());
+            logger.error(initMsg + " The request came from an IP different from the one this worker was registered with: " + workerInfo.getWorkerIP());
             return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
         }
 
diff --git a/src/main/java/eu/openaire/urls_controller/models/BulkImportReport.java b/src/main/java/eu/openaire/urls_controller/models/BulkImportReport.java
index b175425..83c3274 100644
--- a/src/main/java/eu/openaire/urls_controller/models/BulkImportReport.java
+++ b/src/main/java/eu/openaire/urls_controller/models/BulkImportReport.java
@@ -43,7 +43,7 @@ public class BulkImportReport {
 
 
     public void addEvent(String event) {
-        eventsMultimap.put(GenericUtils.getReadableCurrentTimeAndZone(), event);
+        eventsMultimap.put(GenericUtils.getReadableCurrentTimeAndZone(), event);    // This is synchronized.
     }
 
     public String getJsonReport()
diff --git a/src/main/java/eu/openaire/urls_controller/services/BulkImportServiceImpl.java b/src/main/java/eu/openaire/urls_controller/services/BulkImportServiceImpl.java
index fed8455..45574d4 100644
--- a/src/main/java/eu/openaire/urls_controller/services/BulkImportServiceImpl.java
+++ b/src/main/java/eu/openaire/urls_controller/services/BulkImportServiceImpl.java
@@ -78,7 +78,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = "The payloadsSchema could not be parsed!";
             logger.error(errorMsg + additionalLoggingMsg);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         }
@@ -88,7 +88,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = "Could not retrieve the files for bulk-import!";
             logger.error(errorMsg + additionalLoggingMsg);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         }
@@ -98,7 +98,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = "No files were found inside the bulkImportDir: " + bulkImportDirName;
             logger.warn(errorMsg);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         }
@@ -113,7 +113,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = "Could not create the local parquet-directory: " + localParquetDir;
             logger.error(errorMsg + additionalLoggingMsg, e);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         }
@@ -124,7 +124,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = "Could not create the remote HDFS-directory: " + currentBulkImportHdfsDir;
             logger.error(errorMsg + additionalLoggingMsg);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         }
@@ -139,7 +139,7 @@ public class BulkImportServiceImpl implements BulkImportService {
         msg = "Going to bulk-import the " + numOfFiles + " files in parallel, after dividing them in " + subListsSize + " segments.";
         logger.debug(msg + additionalLoggingMsg);
         bulkImportReport.addEvent(msg);
-        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
 
         for ( int i = 0; i < subListsSize; ++i ) {
             int finalI = i;
@@ -180,7 +180,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = "An error occurred when trying to bulk-import data from bulkImportDir: " + bulkImportDirName;
             logger.error(errorMsg, e);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         } finally {
@@ -193,7 +193,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = "None of the files inside the bulkImportDir: " + bulkImportDirName + " were imported!";
             logger.error(errorMsg);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         } else if ( numAllFailedFiles > 0 ) {    // Some failed, but not all.
@@ -204,7 +204,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             logger.info(msg);
         }
         bulkImportReport.addEvent(msg);
-        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
 
         // Merge the parquet files inside the table "payload_bulk_import", to improve performance of future operations.
         DatabaseConnector.databaseLock.lock();
@@ -212,7 +212,7 @@ public class BulkImportServiceImpl implements BulkImportService {
         DatabaseConnector.databaseLock.unlock();
         if ( mergeErrorMsg != null ) {  // the message in already logged
             bulkImportReport.addEvent(mergeErrorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
             BulkImportController.bulkImportDirsUnderProcessing.remove(bulkImportDirName);
             return false;
         }
@@ -220,7 +220,7 @@ public class BulkImportServiceImpl implements BulkImportService {
         String successMsg = "Finished the bulk-import procedure for " + provenance + " and bulkImportDir: " + bulkImportDirName;
         logger.info(successMsg);
         bulkImportReport.addEvent(successMsg);
-        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
+        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), false);
         // The report-file will be overwritten every now and then, instead of appended, since we want to add an update new JSON report-object each time.
         // Also, we do not want to write the object in the end (in its final form), since we want the user to have the ability to request the report at any time,
         // after submitting the bulk-import request, to see its progress (since the number of file may be very large and the processing may take many hours).
@@ -240,6 +240,7 @@ public class BulkImportServiceImpl implements BulkImportService {
         String msg = "Going to import " + numOfFilesInSegment + " files, for segment-" + segmentCounter;
         logger.debug(msg + additionalLoggingMsg);
         bulkImportReport.addEvent(msg);
+        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
 
         List<GenericData.Record> payloadRecords = new ArrayList<>(numOfFilesInSegment);
 
@@ -254,7 +255,7 @@ public class BulkImportServiceImpl implements BulkImportService {
             try {
                 record = processBulkImportedFile(fileLocation, provenance, bulkImportSource, timeMillis, additionalLoggingMsg);
             } catch (Exception e) {
-                String errorMsg = "Exception when uploading the files of segment_" + segmentCounter + " to the S3 Object Store. Will avoid uploading any file for this segment..";
+                String errorMsg = "Exception when uploading the files of segment_" + segmentCounter + " to the S3 Object Store. Will avoid uploading the rest of the files for this segment..";
                 logger.error(errorMsg + additionalLoggingMsg);
                 bulkImportReport.addEvent(errorMsg);
                 for ( int j=i; j < numOfFilesInSegment; ++j )
@@ -269,14 +270,14 @@ public class BulkImportServiceImpl implements BulkImportService {
                 failedFiles.add(fileLocation);
             }
 
-            if ( ((++counter) % 150) == 0 ) {   // Every 150 files, report the status for this segment.
+            if ( ((++counter) % 150) == 0 ) {   // Every 150 files, report the status for this segment and right it to the file.
                 msg = "Progress for segment-" + segmentCounter + " : " + payloadRecords.size() + " files have been imported and " + failedFiles.size() + " have failed, out of " + numOfFilesInSegment + " files.";
                 if ( logger.isTraceEnabled() )
                     logger.trace(msg + additionalLoggingMsg);
                 bulkImportReport.addEvent(msg);
                 fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
             }
-        }
+        } // End of processing files for this segment.
 
         int numOfPayloadRecords = payloadRecords.size();
         if ( numOfPayloadRecords == 0 ) {
@@ -291,7 +292,6 @@ public class BulkImportServiceImpl implements BulkImportService {
             String errorMsg = failedFiles.size() + " out of " + numOfFilesInSegment + " files failed to be bulk-imported, for segment-" + segmentCounter + " !";
             logger.warn(errorMsg + additionalLoggingMsg);
             bulkImportReport.addEvent(errorMsg);
-            fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
         }
 
         // Construct the parquet file, upload it to HDFS and load it in the "payload_bulk_import" table.
@@ -350,11 +350,12 @@ public class BulkImportServiceImpl implements BulkImportService {
             // Delete all files except the ones in the "failedHashSet".
             for ( String fileLocation : fileLocationsSegment ) {
                 if ( !failedFiles.contains(fileLocation) )
-                    if ( !fileUtils.deleteFile(fileLocation) )
+                    if ( !fileUtils.deleteFile(fileLocation) )  // The "error-log-message" is shown inside.
                         bulkImportReport.addEvent("The file " + fileLocation + " could not be deleted! Please make sure you have provided the WRITE-permission.");
             }
         }
 
+        fileUtils.writeToFile(bulkImportReportLocation, bulkImportReport.getJsonReport(), true);
         return (numOfFilesInSegment - numOfPayloadRecords); // Return the numOfFailedFiles.
     }
 
@@ -385,6 +386,10 @@ public class BulkImportServiceImpl implements BulkImportService {
         String datasourcePrefix = bulkImportSource.getDatasourcePrefix();
         String fileNameID = fileLocationData.getFileNameID();
 
+        String openAireId = generateOpenaireId(fileNameID, datasourcePrefix, bulkImportSource.getIsAuthoritative());
+        if ( openAireId == null )
+            return null;
+
         String actualUrl = (bulkImportSource.getPdfUrlPrefix() + fileNameID); // This string-concatenation, works with urls of Arvix. A different construction may be needed for other datasources.
         String originalUrl = actualUrl; // We have the full-text files from bulk-import, so let's assume the original-url is also the full-text-link.
 
@@ -403,10 +408,6 @@ public class BulkImportServiceImpl implements BulkImportService {
             DatabaseConnector.databaseLock.unlock();
         }
 
-        String openAireId = generateOpenaireId(fileNameID, datasourcePrefix, bulkImportSource.getIsAuthoritative());
-        if ( openAireId == null )
-            return null;
-
         String s3Url = null;
 
         if ( alreadyFoundFileLocation != null ) // If the full-text of this record is already-found and uploaded.
diff --git a/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java b/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
index 5199630..5790df6 100644
--- a/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
+++ b/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
@@ -287,7 +287,7 @@ public class UrlsServiceImpl implements UrlsService {
         } else if ( uploadFullTextsResponse == FileUtils.UploadFullTextsResponse.unsuccessful ) {
             logger.error("Failed to get and/or upload the fullTexts for batch-assignments_" + curReportAssignmentsCounter);
             // The docUrls were still found! Just update ALL the fileLocations, sizes, hashes and mimetypes, to show that the files are not available.
-            fileUtils.updateUrlReportsToHaveNoFullTextFiles(urlReports, false);
+            fileUtils.removeUnretrievedFullTextsFromUrlReports(urlReports, false);
             // We write only the payloads which are connected with retrieved full-texts, uploaded to S3-Object-Store.
             // We continue with writing the "attempts", as we want to avoid re-checking the failed-urls later.
             // The urls which give full-text (no matter if we could not get it from the worker), are flagged as "couldRetry" anyway, so they will be picked-up to be checked again later.
diff --git a/src/main/java/eu/openaire/urls_controller/util/FileUtils.java b/src/main/java/eu/openaire/urls_controller/util/FileUtils.java
index deb2366..395bc73 100644
--- a/src/main/java/eu/openaire/urls_controller/util/FileUtils.java
+++ b/src/main/java/eu/openaire/urls_controller/util/FileUtils.java
@@ -243,7 +243,7 @@ public class FileUtils {
         if ( failedBatches == numOfBatches )
             logger.error("None of the " + numOfBatches + " batches could be handled for assignments_" + assignmentsBatchCounter + ", for worker: " + workerId);
 
-        updateUrlReportsToHaveNoFullTextFiles(urlReports, true);    // Make sure all records without an S3-Url have < null > file-data (some batches or uploads might have failed).
+        removeUnretrievedFullTextsFromUrlReports(urlReports, true);    // Make sure all records without an S3-Url have < null > file-data (some batches or uploads might have failed).
         deleteDirectory(new File(curAssignmentsBaseLocation));
 
         // Check and warn about the number of failed payloads.
@@ -617,7 +617,7 @@ public class FileUtils {
 
 
     public static final int twentyFiveKb = 25_600;   // 25 Kb
-    public static final int halfMb = 524_288;   // 0.5 Mb = 512 Kb
+    public static final int halfMb = 524_288;   // 0.5 Mb = 512 Kb = 524_288 bytes
     public static final int tenMb = (10 * 1_048_576);
 
     public boolean saveArchive(HttpURLConnection conn, File zstdFile)
@@ -644,7 +644,7 @@ public class FileUtils {
      * @param urlReports
      * @param shouldCheckAndKeepS3UploadedFiles
      */
-    public void updateUrlReportsToHaveNoFullTextFiles(List<UrlReport> urlReports, boolean shouldCheckAndKeepS3UploadedFiles)
+    public void removeUnretrievedFullTextsFromUrlReports(List<UrlReport> urlReports, boolean shouldCheckAndKeepS3UploadedFiles)
     {
         for ( UrlReport urlReport : urlReports ) {
             Payload payload = urlReport.getPayload();
@@ -703,9 +703,11 @@ public class FileUtils {
         // Get the id and url of any
         String getDataForPayloadPrefillQuery = "select distinct pu.id, pu.url\n" +
                 "from " + DatabaseConnector.databaseName + ".publication_urls pu\n" +
+                // Exclude the "already-processed" pairs.
                 "left anti join " + DatabaseConnector.databaseName + ".attempt a on a.id=pu.id and a.original_url=pu.url\n" +
                 "left anti join " + DatabaseConnector.databaseName + ".payload p on p.id=pu.id and p.original_url=pu.url\n" +
                 "left anti join " + DatabaseConnector.databaseName + ".assignment asgn on asgn.id=pu.id and asgn.original_url=pu.url\n" +
+                // Limit the urls to the ones matching to the payload-urls found for the current assignments.
                 "where pu.url in " + getQueryListString(urlsToRetrieveRelatedIDs, urlsToRetrieveRelatedIDsSize, stringBuilderCapacity);
 
         //logger.trace("getDataForPayloadPrefillQuery:\n" + getDataForPayloadPrefillQuery);