[8.x](backport #41179) x-pack/filebeat/input/entityanalytics/provider/activedirectory: don't publish unmodified updates

CHANGELOG.next.asciidoc

@@ -166,6 +166,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Fix a bug in Salesforce input to only handle responses with 200 status code {pull}41015[41015]
 - Fixed failed job handling and removed false-positive error logs in the GCS input. {pull}41142[41142]
 - Bump github.com/elastic/go-sfdc dependency used by x-pack/filebeat/input/salesforce. {pull}41192[41192]
+- Improve modification time handling for entities and entity deletion logic in the Active Directory entityanalytics input. {pull}41179[41179]
 
 *Heartbeat*
 

x-pack/filebeat/input/entityanalytics/provider/activedirectory/activedirectory.go

@@ -130,16 +130,20 @@ func (p *adInput) Run(inputCtx v2.Context, store *kvstore.Store, client beat.Cli
 	p.cfg.UserAttrs = withMandatory(p.cfg.UserAttrs, "distinguishedName", "whenChanged")
 	p.cfg.GrpAttrs = withMandatory(p.cfg.GrpAttrs, "distinguishedName", "whenChanged")
 
+	var (
+		last time.Time
+		err  error
+	)
 	for {
 		select {
 		case <-inputCtx.Cancelation.Done():
 			if !errors.Is(inputCtx.Cancelation.Err(), context.Canceled) {
 				return inputCtx.Cancelation.Err()
 			}
 			return nil
-		case <-syncTimer.C:
-			start := time.Now()
-			if err := p.runFullSync(inputCtx, store, client); err != nil {
+		case start := <-syncTimer.C:
+			last, err = p.runFullSync(inputCtx, store, client)
+			if err != nil {
 				p.logger.Errorw("Error running full sync", "error", err)
 				p.metrics.syncError.Inc()
 			}
@@ -157,9 +161,9 @@ func (p *adInput) Run(inputCtx v2.Context, store *kvstore.Store, client beat.Cli
 			}
 			updateTimer.Reset(p.cfg.UpdateInterval)
 			p.logger.Debugf("Next update expected at: %v", time.Now().Add(p.cfg.UpdateInterval))
-		case <-updateTimer.C:
-			start := time.Now()
-			if err := p.runIncrementalUpdate(inputCtx, store, client); err != nil {
+		case start := <-updateTimer.C:
+			last, err = p.runIncrementalUpdate(inputCtx, store, last, client)
+			if err != nil {
 				p.logger.Errorw("Error running incremental update", "error", err)
 				p.metrics.updateError.Inc()
 			}
@@ -192,13 +196,13 @@ outer:
 // identities from Azure Active Directory, enrich users with group memberships,
 // and publishes all known users (regardless if they have been modified) to the
 // given beat.Client.
-func (p *adInput) runFullSync(inputCtx v2.Context, store *kvstore.Store, client beat.Client) error {
+func (p *adInput) runFullSync(inputCtx v2.Context, store *kvstore.Store, client beat.Client) (time.Time, error) {
 	p.logger.Debugf("Running full sync...")
 
 	p.logger.Debugf("Opening new transaction...")
 	state, err := newStateStore(store)
 	if err != nil {
-		return fmt.Errorf("unable to begin transaction: %w", err)
+		return time.Time{}, fmt.Errorf("unable to begin transaction: %w", err)
 	}
 	p.logger.Debugf("Transaction opened")
 	defer func() { // If commit is successful, call to this close will be no-op.
@@ -210,48 +214,89 @@ func (p *adInput) runFullSync(inputCtx v2.Context, store *kvstore.Store, client
 
 	ctx := ctxtool.FromCanceller(inputCtx.Cancelation)
 	p.logger.Debugf("Starting fetch...")
-	_, err = p.doFetchUsers(ctx, state, true)
+	users, err := p.doFetchUsers(ctx, state, true)
 	if err != nil {
-		return err
+		return time.Time{}, err
 	}
 
-	if len(state.users) != 0 {
-		tracker := kvstore.NewTxTracker(ctx)
-
-		start := time.Now()
-		p.publishMarker(start, start, inputCtx.ID, true, client, tracker)
-		for _, u := range state.users {
-			p.publishUser(u, state, inputCtx.ID, client, tracker)
+	if len(users) != 0 || state.len() != 0 {
+		// Active Directory does not have a notion of deleted users
+		// beyond absence from the directory, so compare found users
+		// with users already known by the state store and if any
+		// are in the store but not returned in the previous fetch,
+		// mark them as deleted and publish the deletion. We do not
+		// have the time of the deletion, so use now.
+		if state.len() != 0 {
+			found := make(map[string]bool)
+			for _, u := range users {
+				found[u.ID] = true
+			}
+			deleted := make(map[string]*User)
+			now := time.Now()
+			state.forEach(func(u *User) {
+				if u.State == Deleted {
+					// We have already seen that this is deleted
+					// so we do not need to publish again. The
+					// user will be deleted from the store when
+					// the state is closed.
+					return
+				}
+				if found[u.ID] {
+					// We have the user, so we do not need to
+					// mark it as deleted.
+					return
+				}
+				// This modifies the state store's copy since u
+				// is a pointer held by the state store map.
+				u.State = Deleted
+				u.WhenChanged = now
+				deleted[u.ID] = u
+			})
+			for _, u := range deleted {
+				users = append(users, u)
+			}
+		}
+		if len(users) != 0 {
+			var tracker *kvstore.TxTracker
+			start := time.Now()
+			p.publishMarker(start, start, inputCtx.ID, true, client, tracker)
+			tracker = kvstore.NewTxTracker(ctx)
+			for _, u := range users {
+				p.publishUser(u, state, inputCtx.ID, client, tracker)
+			}
+			end := time.Now()
+			p.publishMarker(end, end, inputCtx.ID, false, client, tracker)
+			tracker.Wait()
 		}
-
-		end := time.Now()
-		p.publishMarker(end, end, inputCtx.ID, false, client, tracker)
-
-		tracker.Wait()
 	}
 
 	if ctx.Err() != nil {
-		return ctx.Err()
+		return time.Time{}, ctx.Err()
 	}
 
-	state.lastSync = time.Now()
+	// state.whenChanged is modified by the call to doFetchUsers to be
+	// the latest modification time for all of the users that have been
+	// collected in that call. This will not include any of the deleted
+	// users since they were not collected.
+	latest := state.whenChanged
+	state.lastSync = latest
 	err = state.close(true)
 	if err != nil {
-		return fmt.Errorf("unable to commit state: %w", err)
+		return time.Time{}, fmt.Errorf("unable to commit state: %w", err)
 	}
 
-	return nil
+	return latest, nil
 }
 
 // runIncrementalUpdate will run an incremental update. The process is similar
 // to full synchronization, except only users which have changed (newly
 // discovered, modified, or deleted) will be published.
-func (p *adInput) runIncrementalUpdate(inputCtx v2.Context, store *kvstore.Store, client beat.Client) error {
+func (p *adInput) runIncrementalUpdate(inputCtx v2.Context, store *kvstore.Store, last time.Time, client beat.Client) (time.Time, error) {
 	p.logger.Debugf("Running incremental update...")
 
 	state, err := newStateStore(store)
 	if err != nil {
-		return fmt.Errorf("unable to begin transaction: %w", err)
+		return last, fmt.Errorf("unable to begin transaction: %w", err)
 	}
 	defer func() { // If commit is successful, call to this close will be no-op.
 		closeErr := state.close(false)
@@ -263,62 +308,37 @@ func (p *adInput) runIncrementalUpdate(inputCtx v2.Context, store *kvstore.Store
 	ctx := ctxtool.FromCanceller(inputCtx.Cancelation)
 	updatedUsers, err := p.doFetchUsers(ctx, state, false)
 	if err != nil {
-		return err
+		return last, err
 	}
 
-	var tracker *kvstore.TxTracker
-	if len(updatedUsers) != 0 || state.len() != 0 {
-		// Active Directory does not have a notion of deleted users
-		// beyond absence from the directory, so compare found users
-		// with users already known by the state store and if any
-		// are in the store but not returned in the previous fetch,
-		// mark them as deleted and publish the deletion. We do not
-		// have the time of the deletion, so use now.
-		if state.len() != 0 {
-			found := make(map[string]bool)
-			for _, u := range updatedUsers {
-				found[u.ID] = true
-			}
-			deleted := make(map[string]*User)
-			now := time.Now()
-			state.forEach(func(u *User) {
-				if u.State == Deleted || found[u.ID] {
-					return
-				}
-				// This modifies the state store's copy since u
-				// is a pointer held by the state store map.
-				u.State = Deleted
-				u.WhenChanged = now
-				deleted[u.ID] = u
-			})
-			for _, u := range deleted {
-				updatedUsers = append(updatedUsers, u)
-			}
-		}
-		if len(updatedUsers) != 0 {
-			tracker = kvstore.NewTxTracker(ctx)
-			for _, u := range updatedUsers {
-				p.publishUser(u, state, inputCtx.ID, client, tracker)
-			}
-			tracker.Wait()
+	if len(updatedUsers) != 0 {
+		tracker := kvstore.NewTxTracker(ctx)
+		for _, u := range updatedUsers {
+			p.publishUser(u, state, inputCtx.ID, client, tracker)
 		}
+		tracker.Wait()
 	}
 
 	if ctx.Err() != nil {
-		return ctx.Err()
+		return last, ctx.Err()
 	}
 
-	state.lastUpdate = time.Now()
+	// state.whenChanged is modified by the call to doFetchUsers to be
+	// the latest modification time for all of the users that have been
+	// collected in that call.
+	latest := state.whenChanged
+	state.lastUpdate = latest
 	if err = state.close(true); err != nil {
-		return fmt.Errorf("unable to commit state: %w", err)
+		return last, fmt.Errorf("unable to commit state: %w", err)
 	}
 
-	return nil
+	return latest, nil
 }
 
 // doFetchUsers handles fetching user identities from Active Directory. If
 // fullSync is true, then any existing whenChanged will be ignored, forcing a
-// full synchronization from Active Directory.
+// full synchronization from Active Directory. The whenChanged time of state
+// is modified to be the time stamp of the latest User.WhenChanged value.
 // Returns a set of modified users by ID.
 func (p *adInput) doFetchUsers(ctx context.Context, state *stateStore, fullSync bool) ([]*User, error) {
 	var since time.Time
@@ -332,31 +352,14 @@ func (p *adInput) doFetchUsers(ctx context.Context, state *stateStore, fullSync
 		return nil, err
 	}
 
-	var (
-		users       []*User
-		whenChanged time.Time
-	)
-	if fullSync {
-		for _, u := range entries {
-			state.storeUser(u)
-			if u.WhenChanged.After(whenChanged) {
-				whenChanged = u.WhenChanged
-			}
+	users := make([]*User, 0, len(entries))
+	for _, u := range entries {
+		users = append(users, state.storeUser(u))
+		if u.WhenChanged.After(state.whenChanged) {
+			state.whenChanged = u.WhenChanged
 		}
-	} else {
-		users = make([]*User, 0, len(entries))
-		for _, u := range entries {
-			users = append(users, state.storeUser(u))
-			if u.WhenChanged.After(whenChanged) {
-				whenChanged = u.WhenChanged
-			}
-		}
-		p.logger.Debugf("processed %d users from API", len(users))
 	}
-	if whenChanged.After(state.whenChanged) {
-		state.whenChanged = whenChanged
-	}
-
+	p.logger.Debugf("processed %d users from API", len(users))
 	return users, nil
 }
 

x-pack/filebeat/input/entityanalytics/provider/activedirectory/statestore.go

@@ -170,6 +170,13 @@ func (s *stateStore) close(commit bool) (err error) {
 	}
 
 	for key, value := range s.users {
+		if value.State == Deleted {
+			err = s.tx.Delete(usersBucket, []byte(key))
+			if err != nil {
+				return fmt.Errorf("unable to delete user %q from state: %w", key, err)
+			}
+			continue
+		}
 		err = s.tx.Set(usersBucket, []byte(key), value)
 		if err != nil {
 			return fmt.Errorf("unable to save user %q to state: %w", key, err)