- Add a scheduling job to delete assignments older than 7 days. These may be left behind when the worker throws a "SocketTimeoutException" before it can receive the assignments and process them. No workerReport gets created for those assignments.

- Improve some log-messages.
- Code polishing.

src/main/java/eu/openaire/urls_controller/UrlsControllerApplication.java

@@ -31,9 +31,9 @@ import java.util.concurrent.TimeUnit;
 
 @SpringBootApplication
 @EnableScheduling
-public class Application {
+public class UrlsControllerApplication {
 
-    private static final Logger logger = LoggerFactory.getLogger(Application.class);
+    private static final Logger logger = LoggerFactory.getLogger(UrlsControllerApplication.class);
 
     @Autowired
     HikariDataSource hikariDataSource;
@@ -42,7 +42,7 @@ public class Application {
 
 
     public static void main(String[] args) {
-        context = SpringApplication.run(Application.class, args);
+        context = SpringApplication.run(UrlsControllerApplication.class, args);
     }
 
     @Bean

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

@@ -2,7 +2,7 @@ package eu.openaire.urls_controller.components;
 
 import com.google.gson.Gson;
 import com.google.gson.JsonSyntaxException;
-import eu.openaire.urls_controller.Application;
+import eu.openaire.urls_controller.UrlsControllerApplication;
 import eu.openaire.urls_controller.configuration.DatabaseConnector;
 import eu.openaire.urls_controller.controllers.BulkImportController;
 import eu.openaire.urls_controller.controllers.ShutdownController;
@@ -24,10 +24,7 @@ import org.springframework.stereotype.Component;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Date;
-import java.util.List;
-import java.util.Set;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
@@ -48,7 +45,7 @@ public class ScheduledTasks {
     UrlsServiceImpl urlsService;
 
     @Autowired
-    private Application application;
+    private UrlsControllerApplication urlsControllerApplication;
 
     private final StatsController statsController;
 
@@ -173,7 +170,7 @@ public class ScheduledTasks {
 
         // Any left-over worker-reports are kept to be retried next time the Controller starts.
 
-        application.gentleAppShutdown();
+        urlsControllerApplication.gentleAppShutdown();
     }
 
 
@@ -232,6 +229,25 @@ public class ScheduledTasks {
     }
 
 
+    @Scheduled(initialDelay = 604_800_000, fixedDelay = 604_800_000)  // Run every 7 days.
+    //@Scheduled(initialDelay = 1_200_000, fixedDelay = 1_200_000)    // Just for testing (every 1200 secs).
+    public void checkAndDeleteUnhandledAssignments()
+    {
+        // Remove the assignments having a "date" older than 7 days.
+
+        // For some reason, sometimes, the worker cannot receive the assignments in time.
+        // In this case, no job is created for those assignments nd no workerReport gets stored in storage.
+        // The assignments just remain in the table, and the urls cannot be rechecked.
+
+        Calendar calendar = Calendar.getInstance();
+        calendar.add(Calendar.DAY_OF_MONTH, -7);    // Subtract 7 days from current.
+
+        DatabaseConnector.databaseLock.lock();
+        urlsService.deleteAssignmentsWithOlderDate(calendar.getTimeInMillis());   // Any error-log is written inside.
+        DatabaseConnector.databaseLock.unlock();
+    }
+
+
     // Scheduled Metrics for Prometheus.
     // Prometheus scrapes for metrics usually every 15 seconds, but that is an extremely short time-period for DB-statistics.
 

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

@@ -212,7 +212,7 @@ public class UrlsServiceImpl implements UrlsService {
         else if ( assignmentsSize < assignmentsLimit )
             logger.warn("The retrieved results were fewer (" + assignmentsSize + ") than the \"assignmentsLimit\" (" + assignmentsLimit + "), for worker with id: " + workerId + ". Will increase the \"maxAttempts\" to " + maxAttemptsPerRecordAtomic.incrementAndGet() + ", for the next requests.");
 
-        logger.debug("Finished gathering " + assignmentsSize + " assignments for worker with id \"" + workerId + "\". Going to insert them into the \"assignment\" table and then return them to the worker.");
+        logger.debug("Finished gathering " + assignmentsSize + " assignments for worker with id \"" + workerId + "\". Going to insert them into the \"assignment\" table and then return them to the worker. | assignments_" + curAssignmentsBatchCounter);
 
         // Write the Assignment details to the assignment-table.
         String insertAssignmentsQuery = "insert into " + DatabaseConnector.databaseName + ".assignment \n select pubid, url, '" + workerId + "', " + curAssignmentsBatchCounter + ", " + timestampMillis
@@ -236,7 +236,7 @@ public class UrlsServiceImpl implements UrlsService {
 
         // We do not need to "merge" the parquet files for the "assignment" table here, since this happens every time we delete the assignments of a specific batch.
 
-        logger.debug("Finished inserting " + assignmentsSize + " assignments into the \"assignment\"-table.");
+        logger.debug("Finished inserting " + assignmentsSize + " assignments into the \"assignment\"-table. | curAssignmentsBatchCounter: " + curAssignmentsBatchCounter + " | worker: " + workerId);
 
         // Due to the fact that one publication with an id-url pair can be connected with multiple datasources, the results returned from the query may be duplicates.
         // So, we apply a post-processing step where we collect only one instance of each id-url pair and send it to the Worker.
@@ -410,9 +410,7 @@ public class UrlsServiceImpl implements UrlsService {
             return false;
         }
 
-        // For every "numOfWorkers" assignment-batches that go to workers, we merge the tables, once a workerReport comes in.
+        // For every "numOfWorkers" assignment-batches that get processed, we merge the "attempts" and "payload_aggregated" tables.
-        // After the first few increases of "assignmentsBatchCounter" until all workers get assignment-batches,
-        // there will always be a time when the counter will be just before the "golden-value" and then one workerReport has to be processed here and the counter will be incremented by one and signal the merging-time.
         if ( (currentNumOfWorkerReportsProcessed % UrlsController.numOfWorkers.get()) == 0 )    // The workersNum will not be zero!
             if ( ! mergeWorkerRelatedTables(curWorkerId, curReportAssignmentsCounter, hasAttemptParquetFileProblem, hasPayloadParquetFileProblem) )
                 // The "postReportResultToWorker()" was called inside.
@@ -508,11 +506,21 @@ public class UrlsServiceImpl implements UrlsService {
         // This will delete the rows of the "assignment" table which refer to the "givenAssignmentsBatchCounter".
         // As we have non-KUDU Impala tables, the Delete operation can only succeed through a "merge" operation of the rest of the data.
         // Only the rows referring to OTHER "givenAssignmentsBatchCounter" get stored in a temp-table, while the "assignment" table gets deleted. Then, the temp_table becomes the "assignment" table.
-        // We don't need to keep the assignment-info anymore, the "findAssignmentsQuery" checks the "payload" table for previously handled tasks.
+        // We don't need to keep the assignment-info forever, as the "findAssignmentsQuery" checks the "payload" table for previously handled tasks.
         return fileUtils.mergeParquetFiles("assignment", " WHERE assignments_batch_counter != ", givenAssignmentsBatchCounter);
     }
 
 
+    public String deleteAssignmentsWithOlderDate(long givenDate)
+    {
+        // This will delete the rows of the "assignment" table which are older than "givenDate".
+        // As we have non-KUDU Impala tables, the Delete operation can only succeed through a "merge" operation of the rest of the data.
+        // Only the rows referring to NEWER than "givenDate" get stored in a temp-table, while the "assignment" table gets deleted. Then, the temp_table becomes the "assignment" table.
+        // We don't need to keep the assignment-info forever, as the "findAssignmentsQuery" checks the "payload" table for previously handled tasks.
+        return fileUtils.mergeParquetFiles("assignment", " WHERE `date` >= ", givenDate);
+    }
+    
+
     private static final RestTemplate restTemplate = new RestTemplate();
 
     private boolean postReportResultToWorker(String workerId, long assignmentRequestCounter, String errorMsg)