- Increase the initialDelay for the "checkIfServiceIsReadyForShutdown" scheduled-task, in production, to 10 minutes.

- Code polishing.

src/main/java/eu/openaire/urls_controller/components/ScheduledTasks.java

@@ -54,9 +54,8 @@ public class ScheduledTasks {
             return;
 
         // Immediately delete the selected tasks form the global list, so that if these tasks are not finished before the scheduler runs again, they will not be re-executed.
-        for ( Callable<Boolean> selectedTask : tempList ) {
+        for ( Callable<Boolean> selectedTask : tempList )
             UrlsController.backgroundCallableTasks.remove(selectedTask);
-        }
 
         logger.debug(numOfTasks + " background tasks were found inside the \"backgroundCallableTasks\" list and are about to be executed.");
         // Execute the tasks and wait for them to finish.
@@ -82,7 +81,7 @@ public class ScheduledTasks {
     }
 
 
-    @Scheduled(initialDelay = 60_000, fixedDelay = 7_200_000)  // Check every 2 hours.
+    @Scheduled(initialDelay = 600_000, fixedDelay = 7_200_000)  // Check every 2 hours. The initial delay is 10 minutes, to allow to shut down quickly in case of problem when starting, but also account for the initial communication with the Workers, where a problem may appear.
     //@Scheduled(initialDelay = 60_000, fixedDelay = 20_000)    // Just for testing (every 20 secs).
     public void checkIfServiceIsReadyForShutdown()
     {
@@ -91,10 +90,9 @@ public class ScheduledTasks {
 
         // If the workers have shutdown on their own, without been instructed to by the Controller, then the Controller will keep running.
 
-        for ( String workerId : UrlsController.workersInfoMap.keySet() ) {
+        for ( String workerId : UrlsController.workersInfoMap.keySet() )
             if ( ! UrlsController.workersInfoMap.get(workerId).getHasShutdown() ) // The workerId is certainly inside the map and has a workerInfo value.
                 return; // If at least 1 worker is still active, then do not shut down the server.
-        }
 
         logger.info("All workers have already shutdown. Shutting down the Controller..");
         Application.gentleAppShutdown();

src/main/java/eu/openaire/urls_controller/controllers/ShutdownController.java

@@ -2,6 +2,7 @@ package eu.openaire.urls_controller.controllers;
 
 import eu.openaire.urls_controller.models.WorkerInfo;
 import eu.openaire.urls_controller.services.ShutdownService;
+import eu.openaire.urls_controller.util.GenericUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -97,10 +98,7 @@ public class ShutdownController {
             return ResponseEntity.badRequest().body(errorMsg);
         }
 
-        String remoteAddr = request.getHeader("X-FORWARDED-FOR");
-        if ( remoteAddr == null || remoteAddr.isEmpty() )
-            remoteAddr = request.getRemoteAddr();
-
+        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 the IP: " + workerInfo.getWorkerIP());
             return ResponseEntity.status(HttpStatus.FORBIDDEN).build();

src/main/java/eu/openaire/urls_controller/controllers/UrlsController.java

@@ -5,6 +5,7 @@ import eu.openaire.urls_controller.models.WorkerInfo;
 import eu.openaire.urls_controller.payloads.requests.WorkerReport;
 import eu.openaire.urls_controller.services.UrlsService;
 import eu.openaire.urls_controller.util.FileUtils;
+import eu.openaire.urls_controller.util.GenericUtils;
 import eu.openaire.urls_controller.util.ParquetFileUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -103,9 +104,7 @@ public class UrlsController {
             logger.error("The \"HttpServletRequest\" is null!");
             return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
         }
-        String remoteAddr = request.getHeader("X-FORWARDED-FOR");
-        if ( (remoteAddr == null) || remoteAddr.isEmpty() )
-            remoteAddr = request.getRemoteAddr();
+        String remoteAddr = GenericUtils.getRequestorAddress(request);
 
         WorkerInfo workerInfo = workersInfoMap.get(workerId);
         if ( workerInfo != null ) { // This worker has already been identified.

src/main/java/eu/openaire/urls_controller/services/ShutdownServiceImpl.java

@@ -1,6 +1,7 @@
 package eu.openaire.urls_controller.services;
 
 import eu.openaire.urls_controller.controllers.UrlsController;
+import eu.openaire.urls_controller.util.GenericUtils;
 import eu.openaire.urls_controller.util.UriBuilder;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -27,9 +28,7 @@ public class ShutdownServiceImpl implements ShutdownService {
             logger.error(initMsg + "The \"HttpServletRequest\" is null!");
             return ResponseEntity.internalServerError().build();
         }
-        String remoteAddr = request.getHeader("X-FORWARDED-FOR");
-        if ( remoteAddr == null || remoteAddr.isEmpty() )
-            remoteAddr = request.getRemoteAddr();
+        String remoteAddr = GenericUtils.getRequestorAddress(request);
 
         //  In case the Controller is running inside a docker container, and we want to send the "shutdownServiceRequest" from the terminal (with curl), without entering inside the container,
         //  then the request will appear coming from a local IP (192.168.X.Y), instead of localhost.

src/main/java/eu/openaire/urls_controller/util/GenericUtils.java

@@ -1,5 +1,6 @@
 package eu.openaire.urls_controller.util;
 
+import javax.servlet.http.HttpServletRequest;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 
@@ -30,4 +31,13 @@ public class GenericUtils {
         return sb.toString();
     }
 
+
+    public static String getRequestorAddress(HttpServletRequest request)
+    {
+        String remoteAddr = request.getHeader("X-FORWARDED-FOR");   // This retrieves the original IP address, if the request passes through a proxy server.
+        if ( remoteAddr == null )
+            remoteAddr = request.getRemoteAddr();
+        return remoteAddr;
+    }
+
 }