Introduce eventual consistent project modification date update (#1239)

Handles optimistic locking exceptions in case of massive concurrent project resource access.

Author: sven1103

project-management-infrastructure/src/main/java/life/qbic/projectmanagement/infrastructure/project/ProjectRepositoryImpl.java

@@ -99,17 +99,11 @@ public Optional<Project> find(ProjectId projectId) {
   }
 
   /**
-   * Updates the lastModified time of the project. Does not check credentials, as the jobrunner
-   * needs to call it. 
-   * <p>
-   * <b>Use with care!</b>
-   * @param projectId  the id of the project to update
-   * @param modifiedOn the Instant object denoting the time the project was updated
+   * Saves a project to the repository.
+   * @param project the project to save persistently
+   * @since 1.11.1
    */
-  @Override
-  public void unsafeUpdateLastModified(ProjectId projectId, Instant modifiedOn) {
-    var project = projectRepo.findById(projectId).orElseThrow(ProjectNotFoundException::new);
-    project.setLastModified(modifiedOn);
+  public void save(Project project) {
     projectRepo.save(project);
   }
 

project-management/src/main/java/life/qbic/projectmanagement/application/ProjectInformationService.java

@@ -2,7 +2,9 @@
 
 import static java.util.function.Predicate.not;
 
+import java.time.Duration;
 import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
@@ -23,6 +25,7 @@
 import life.qbic.projectmanagement.domain.model.project.ProjectObjective;
 import life.qbic.projectmanagement.domain.model.project.ProjectTitle;
 import life.qbic.projectmanagement.domain.repository.ProjectRepository;
+import org.hibernate.dialect.lock.OptimisticEntityLockException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.security.core.Authentication;
@@ -204,7 +207,54 @@ public void removeFunding(ProjectId projectId) {
     projectRepository.update(project);
   }
 
-  public void updateModifiedDate(ProjectId projectID, Instant modifiedOn) {
-    projectRepository.unsafeUpdateLastModified(projectID, modifiedOn);
+  public void updateModifiedDate(ProjectId projectID, Instant modifiedOn) throws ProjectNotFoundException {
+    // The update might fail due to an optimistic locking exception (concurrent access of other processes)
+    // To address this, the update is tried until it will eventually not throw the locking exception anymore.
+    // This approach naively assumes, that the locked resource will be released eventually again by the other process.
+    var attempt = 1;
+    var project = projectRepository.find(projectID).orElseThrow(() -> new ProjectNotFoundException("Project with not found: %s".formatted(projectID)));
+    while(true) {
+      try {
+        tryToUpdateModifiedDate(project, modifiedOn);
+        return;
+      } catch (OptimisticEntityLockException e) {
+        log.debug("Optimistic lock exception occurred while updating modified date for project " + projectID);
+      }
+      try {
+        Thread.sleep(calcBase2Duration(attempt));
+      } catch (InterruptedException e) {
+        log.error("Interrupted while updating modified date for project " + projectID);
+        // We try one last time
+        tryToUpdateModifiedDate(project, modifiedOn);
+        Thread.currentThread().interrupt();
+      }
+      attempt++;
+    }
+  }
+  /*
+  Will only update the last modified date in case the passed instant is newer then the
+  the already stored one in the project.
+   */
+  private void tryToUpdateModifiedDate(Project project, Instant modifiedOn) throws OptimisticEntityLockException {
+    if (project.getLastModified() == null) {
+      project.setLastModified(modifiedOn);
+    }
+    if (project.getLastModified().isAfter(modifiedOn)) {
+      // Nothing to do if the passed instant is before the already stored one
+      return;
+    }
+    project.setLastModified(modifiedOn);
+    projectRepository.save(project);
   }
+
+  private static Duration calcBase2Duration(int attempt) {
+    return Duration.of((long) Math.pow(2.0, attempt) * 100, ChronoUnit.MILLIS);
+  }
+
+  public class ProjectNotFoundException extends RuntimeException {
+    public ProjectNotFoundException(String message) {
+      super(message);
+    }
+  }
+
 }

project-management/src/main/java/life/qbic/projectmanagement/domain/repository/ProjectRepository.java

@@ -1,6 +1,5 @@
 package life.qbic.projectmanagement.domain.repository;
 
-import java.time.Instant;
 import java.util.Optional;
 import life.qbic.projectmanagement.domain.model.project.Project;
 import life.qbic.projectmanagement.domain.model.project.ProjectCode;
@@ -17,7 +16,7 @@
 public interface ProjectRepository {
 
   /**
-   * Saves a {@link Project} entity permanently.
+   * Adds a {@link Project} entity permanently and sets access rights according to the logged in user.
    *
    * @param project the project to store
    * @since 1.0.0
@@ -32,6 +31,13 @@ public interface ProjectRepository {
    */
   void update(Project project);
 
+  /**
+   * Saves a project to the repository
+   * @param project the project to save
+   * @since 1.11.1
+   */
+  void save(Project project);
+
   /**
    * Searches for a project that contain the provided project code
    *
@@ -43,8 +49,6 @@ public interface ProjectRepository {
 
   Optional<Project> find(ProjectId projectId);
 
-  void unsafeUpdateLastModified(ProjectId projectId, Instant modifiedOn);
-
   /**
    * Is thrown if a project that should be created already exists, as denoted by the project id
    */