From e771b50b4ae69659f785e903011103bd248ce723 Mon Sep 17 00:00:00 2001
From: Markus Wieland <markus.wieland@sap.com>
Date: Wed, 1 Oct 2025 17:03:01 +0200
Subject: [PATCH 1/5] Refactor Nova API to unify migration retrieval methods
 and update sync logic

---
 internal/sync/openstack/nova/nova_api.go      |  15 +-
 internal/sync/openstack/nova/nova_api_test.go |  88 +++++------
 internal/sync/openstack/nova/nova_sync.go     | 147 +++---------------
 .../sync/openstack/nova/nova_sync_test.go     |   4 +-
 4 files changed, 63 insertions(+), 191 deletions(-)

diff --git a/internal/sync/openstack/nova/nova_api.go b/internal/sync/openstack/nova/nova_api.go
index 07afd29c..b339d584 100644
--- a/internal/sync/openstack/nova/nova_api.go
+++ b/internal/sync/openstack/nova/nova_api.go
@@ -32,8 +32,8 @@ type NovaAPI interface {
 	GetAllHypervisors(ctx context.Context) ([]Hypervisor, error)
 	// Get all nova flavors.
 	GetAllFlavors(ctx context.Context) ([]Flavor, error)
-	// Get all changed nova migrations since the timestamp.
-	GetChangedMigrations(ctx context.Context, changedSince *time.Time) ([]Migration, error)
+	// Get all nova migrations.
+	GetAllMigrations(ctx context.Context) ([]Migration, error)
 	// Get all aggregates.
 	GetAllAggregates(ctx context.Context) ([]Aggregate, error)
 }
@@ -226,10 +226,10 @@ func (api *novaAPI) GetAllFlavors(ctx context.Context) ([]Flavor, error) {
 	return data.Flavors, nil
 }
 
-// Get all changed Nova migrations.
-func (api *novaAPI) GetChangedMigrations(ctx context.Context, changedSince *time.Time) ([]Migration, error) {
+// Get all Nova migrations.
+func (api *novaAPI) GetAllMigrations(ctx context.Context) ([]Migration, error) {
 	label := Migration{}.TableName()
-	slog.Info("fetching nova data", "label", label, "changedSince", changedSince)
+	slog.Info("fetching nova data", "label", label)
 	// Note: currently we need to fetch this without gophercloud.
 	// See: https://github.com/gophercloud/gophercloud/pull/3244
 	if api.mon.PipelineRequestTimer != nil {
@@ -238,11 +238,6 @@ func (api *novaAPI) GetChangedMigrations(ctx context.Context, changedSince *time
 		defer timer.ObserveDuration()
 	}
 	initialURL := api.sc.Endpoint + "os-migrations"
-	// It is important to omit the changes-since parameter if it is nil.
-	// Otherwise Nova may return huge amounts of data since the beginning of time.
-	if changedSince != nil {
-		initialURL += "?changes-since=" + changedSince.Format(time.RFC3339)
-	}
 	var nextURL = &initialURL
 	var migrations []Migration
 	for nextURL != nil {
diff --git a/internal/sync/openstack/nova/nova_api_test.go b/internal/sync/openstack/nova/nova_api_test.go
index 26aca709..69a11ea8 100644
--- a/internal/sync/openstack/nova/nova_api_test.go
+++ b/internal/sync/openstack/nova/nova_api_test.go
@@ -191,60 +191,46 @@ func TestNovaAPI_GetAllFlavors(t *testing.T) {
 	}
 }
 
-func TestNovaAPI_GetChangedMigrations(t *testing.T) {
-	tests := []struct {
-		name string
-		time *time.Time
-	}{
-		{"nil", nil},
-		{"time", &time.Time{}},
-	}
-	for _, tt := range tests {
-		handler := func(w http.ResponseWriter, r *http.Request) {
-			if tt.time == nil {
-				// Check that the changes-since query parameter is not set.
-				if r.URL.Query().Get("changes-since") != "" {
-					t.Fatalf("expected no changes-since query parameter, got %s", r.URL.Query().Get("changes-since"))
-				}
-			} else {
-				if r.URL.Query().Get("changes-since") != tt.time.Format(time.RFC3339) {
-					t.Fatalf("expected changes-since query parameter to be %s, got %s", tt.time.Format(time.RFC3339), r.URL.Query().Get("changes-since"))
-				}
-			}
-			w.Header().Add("Content-Type", "application/json")
-			w.WriteHeader(http.StatusOK)
-			resp := struct {
-				Migrations []Migration `json:"migrations"`
-				Links      []struct {
-					Rel  string `json:"rel"`
-					Href string `json:"href"`
-				} `json:"migrations_links"`
-			}{
-				Migrations: []Migration{{ID: 1, SourceCompute: "host1", DestCompute: "host2", Status: "completed"}},
-			}
-			if err := json.NewEncoder(w).Encode(resp); err != nil {
-				t.Fatalf("failed to write response: %v", err)
-			}
+func TestNovaAPI_GetAllMigrations(t *testing.T) {
+	handler := func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Query().Get("changes-since") != "" {
+			t.Fatalf("expected no changes-since query parameter, got %s", r.URL.Query().Get("changes-since"))
 		}
-		server, k := setupNovaMockServer(handler)
-		defer server.Close()
+		w.Header().Add("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		resp := struct {
+			Migrations []Migration `json:"migrations"`
+			Links      []struct {
+				Rel  string `json:"rel"`
+				Href string `json:"href"`
+			} `json:"migrations_links"`
+		}{
+			Migrations: []Migration{{ID: 1, SourceCompute: "host1", DestCompute: "host2", Status: "completed"}},
+		}
+		if err := json.NewEncoder(w).Encode(resp); err != nil {
+			t.Fatalf("failed to write response: %v", err)
+		}
+	}
 
-		mon := sync.Monitor{}
-		conf := NovaConf{Availability: "public"}
+	server, k := setupNovaMockServer(handler)
+	defer server.Close()
 
-		api := NewNovaAPI(mon, k, conf).(*novaAPI)
-		api.Init(t.Context())
+	mon := sync.Monitor{}
+	conf := NovaConf{Availability: "public"}
 
-		ctx := t.Context()
-		migrations, err := api.GetChangedMigrations(ctx, tt.time)
-		if err != nil {
-			t.Fatalf("expected no error, got %v", err)
-		}
-		if len(migrations) != 1 {
-			t.Fatalf("expected 1 migration, got %d", len(migrations))
-		}
-		if migrations[0].ID != 1 || migrations[0].SourceCompute != "host1" || migrations[0].DestCompute != "host2" || migrations[0].Status != "completed" {
-			t.Errorf("unexpected migration data: %+v", migrations[0])
-		}
+	api := NewNovaAPI(mon, k, conf).(*novaAPI)
+	api.Init(t.Context())
+
+	ctx := t.Context()
+	migrations, err := api.GetAllMigrations(ctx)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
 	}
+	if len(migrations) != 1 {
+		t.Fatalf("expected 1 migration, got %d", len(migrations))
+	}
+	if migrations[0].ID != 1 || migrations[0].SourceCompute != "host1" || migrations[0].DestCompute != "host2" || migrations[0].Status != "completed" {
+		t.Errorf("unexpected migration data: %+v", migrations[0])
+	}
+
 }
diff --git a/internal/sync/openstack/nova/nova_sync.go b/internal/sync/openstack/nova/nova_sync.go
index 133a0c1a..494a19c4 100644
--- a/internal/sync/openstack/nova/nova_sync.go
+++ b/internal/sync/openstack/nova/nova_sync.go
@@ -5,7 +5,6 @@ package nova
 
 import (
 	"context"
-	"log/slog"
 	"slices"
 	"time"
 
@@ -15,24 +14,6 @@ import (
 	"github.com/go-gorp/gorp"
 )
 
-// Table to store which sync runs where performed and when.
-type novaSync struct {
-	// Name of the sync run.
-	Name string `db:"name"`
-	// Time when the sync run was performed.
-	Time time.Time `db:"time"`
-}
-
-// Table under which the nova sync will be stored.
-func (novaSync) TableName() string {
-	return "nova_sync"
-}
-
-// Indexes for the nova sync table.
-func (novaSync) Indexes() []db.Index {
-	return nil
-}
-
 // Syncer for OpenStack nova.
 type NovaSyncer struct {
 	// Database to store the nova objects in.
@@ -50,7 +31,7 @@ type NovaSyncer struct {
 // Init the OpenStack nova syncer.
 func (s *NovaSyncer) Init(ctx context.Context) {
 	s.API.Init(ctx)
-	tables := []*gorp.TableMap{s.DB.AddTable(novaSync{})}
+	tables := []*gorp.TableMap{}
 	// Only add the tables that are configured in the yaml conf.
 	if slices.Contains(s.Conf.Types, "servers") {
 		tables = append(tables, s.DB.AddTable(Server{}))
@@ -79,148 +60,62 @@ func (s *NovaSyncer) Init(ctx context.Context) {
 func (s *NovaSyncer) Sync(ctx context.Context) error {
 	// Only sync the objects that are configured in the yaml conf.
 	if slices.Contains(s.Conf.Types, "servers") {
-		changedServers, err := s.SyncAllServers(ctx)
+		allServers, err := s.SyncAllServers(ctx)
 		if err != nil {
 			return err
 		}
-		if len(changedServers) > 0 {
+		if len(allServers) > 0 {
 			go s.MqttClient.Publish(TriggerNovaServersSynced, "")
 		}
 	}
 	if slices.Contains(s.Conf.Types, "deleted_servers") {
-		changedDeletedServers, err := s.SyncDeletedServers(ctx)
+		deletedServers, err := s.SyncDeletedServers(ctx)
 		if err != nil {
 			return err
 		}
-		if len(changedDeletedServers) > 0 {
+		if len(deletedServers) > 0 {
 			go s.MqttClient.Publish(TriggerNovaDeletedServersSynced, "")
 		}
 	}
 	if slices.Contains(s.Conf.Types, "hypervisors") {
-		_, err := s.SyncAllHypervisors(ctx)
+		allHypervisors, err := s.SyncAllHypervisors(ctx)
 		if err != nil {
 			return err
 		}
-		go s.MqttClient.Publish(TriggerNovaHypervisorsSynced, "")
+		if len(allHypervisors) > 0 {
+			go s.MqttClient.Publish(TriggerNovaHypervisorsSynced, "")
+		}
 	}
 	if slices.Contains(s.Conf.Types, "flavors") {
-		changedFlavors, err := s.SyncAllFlavors(ctx)
+		allFlavors, err := s.SyncAllFlavors(ctx)
 		if err != nil {
 			return err
 		}
-		if len(changedFlavors) > 0 {
+		if len(allFlavors) > 0 {
 			go s.MqttClient.Publish(TriggerNovaFlavorsSynced, "")
 		}
 	}
 	if slices.Contains(s.Conf.Types, "migrations") {
-		changedMigrations, err := s.SyncChangedMigrations(ctx)
+		allMigrations, err := s.SyncAllMigrations(ctx)
 		if err != nil {
 			return err
 		}
-		if len(changedMigrations) > 0 {
+		if len(allMigrations) > 0 {
 			go s.MqttClient.Publish(TriggerNovaMigrationsSynced, "")
 		}
 	}
 	if slices.Contains(s.Conf.Types, "aggregates") {
-		changedAggregates, err := s.SyncAllAggregates(ctx)
+		allAggregates, err := s.SyncAllAggregates(ctx)
 		if err != nil {
 			return err
 		}
-		if len(changedAggregates) > 0 {
+		if len(allAggregates) > 0 {
 			go s.MqttClient.Publish(TriggerNovaAggregatesSynced, "")
 		}
 	}
 	return nil
 }
 
-// Check when the last sync run for a specific table was performed.
-// If there was no sync run, return nil.
-func (s *NovaSyncer) getLastSyncTime(tableName string) *time.Time {
-	// Check when the last sync run was performed, if there was one.
-	var lastSyncTime *time.Time
-	var lastSync novaSync
-	table := novaSync{}.TableName()
-	if err := s.DB.SelectOne(&lastSync, `
-		SELECT * FROM `+table+`
-		WHERE name = :name ORDER BY time DESC LIMIT 1
-	`, map[string]any{"name": tableName}); err == nil {
-		lastSyncTime = &lastSync.Time
-		slog.Info("last nova sync run", "time", lastSync.Time, "table", tableName)
-	} else {
-		slog.Info("no previous nova sync run", "table", tableName)
-	}
-	return lastSyncTime
-}
-
-// Store a new sync run in the database.
-func (s *NovaSyncer) setLastSyncTime(tableName string, time time.Time) {
-	if err := s.DB.Insert(&novaSync{Name: tableName, Time: time}); err != nil {
-		slog.Error("failed to insert nova sync", "error", err)
-	}
-}
-
-// Upsert nova objects into the database.
-func upsert[O any](s *NovaSyncer, objects []O, pk string, getpk func(O) string, tableName string) error {
-	nObjectsInDB := 0
-	q := "SELECT COUNT(*) FROM " + tableName
-	if err := s.DB.SelectOne(&nObjectsInDB, q); err != nil {
-		return err
-	}
-	var existingObjects []O
-	if nObjectsInDB > 0 && len(objects) > 0 {
-		// Check which objects only need to be updated instead of inserted.
-		// Using a contains query with the object ID:
-		q = "SELECT " + pk + " FROM " + tableName + " WHERE " + pk + " IN ("
-		for i, object := range objects {
-			if i > 0 {
-				q += ", "
-			}
-			q += "'" + getpk(object) + "'"
-		}
-		q += ")"
-		if _, err := s.DB.Select(&existingObjects, q); err != nil {
-			return err
-		}
-	}
-	existingObjectsByID := make(map[string]O, len(existingObjects))
-	for _, object := range existingObjects {
-		existingObjectsByID[getpk(object)] = object
-	}
-	tx, err := s.DB.Begin()
-	if err != nil {
-		return err
-	}
-	for _, object := range objects {
-		if _, ok := existingObjectsByID[getpk(object)]; ok {
-			if _, err := tx.Update(&object); err != nil {
-				return tx.Rollback()
-			}
-		} else {
-			if err := tx.Insert(&object); err != nil {
-				return tx.Rollback()
-			}
-		}
-	}
-	if err := tx.Commit(); err != nil {
-		slog.Error("failed to commit transaction", "error", err)
-	}
-	// Check how many objects we have in the database.
-	q = "SELECT COUNT(*) FROM " + tableName
-	var count int
-	if err := s.DB.SelectOne(&count, q); err != nil {
-		return err
-	}
-	if s.Mon.PipelineObjectsGauge != nil {
-		gauge := s.Mon.PipelineObjectsGauge.WithLabelValues(tableName)
-		gauge.Set(float64(count))
-	}
-	if s.Mon.PipelineRequestProcessedCounter != nil {
-		counter := s.Mon.PipelineRequestProcessedCounter.WithLabelValues(tableName)
-		counter.Inc()
-	}
-	return nil
-}
-
 // Sync all the active OpenStack servers into the database. (Includes ERROR, SHUTOFF, etc. state)
 func (s *NovaSyncer) SyncAllServers(ctx context.Context) ([]Server, error) {
 	allServers, err := s.API.GetAllServers(ctx)
@@ -285,20 +180,16 @@ func (s *NovaSyncer) SyncAllFlavors(ctx context.Context) ([]Flavor, error) {
 }
 
 // Sync the OpenStack migrations into the database.
-func (s *NovaSyncer) SyncChangedMigrations(ctx context.Context) ([]Migration, error) {
-	tableName := Migration{}.TableName()
-	updatedSyncTime := time.Now()
-	lastSyncTime := s.getLastSyncTime(tableName)
-	changedMigrations, err := s.API.GetChangedMigrations(ctx, lastSyncTime)
+func (s *NovaSyncer) SyncAllMigrations(ctx context.Context) ([]Migration, error) {
+	allMigrations, err := s.API.GetAllMigrations(ctx)
 	if err != nil {
 		return nil, err
 	}
-	err = upsert(s, changedMigrations, "uuid", func(m Migration) string { return m.UUID }, tableName)
+	err = db.ReplaceAll(s.DB, allMigrations...)
 	if err != nil {
 		return nil, err
 	}
-	s.setLastSyncTime(tableName, updatedSyncTime)
-	return changedMigrations, nil
+	return allMigrations, nil
 }
 
 func (s *NovaSyncer) SyncAllAggregates(ctx context.Context) ([]Aggregate, error) {
diff --git a/internal/sync/openstack/nova/nova_sync_test.go b/internal/sync/openstack/nova/nova_sync_test.go
index 30e917a7..a8244e69 100644
--- a/internal/sync/openstack/nova/nova_sync_test.go
+++ b/internal/sync/openstack/nova/nova_sync_test.go
@@ -48,7 +48,7 @@ func (m *mockNovaAPI) GetAllFlavors(ctx context.Context) ([]Flavor, error) {
 	return []Flavor{{ID: "1", Name: "flavor1"}}, nil
 }
 
-func (m *mockNovaAPI) GetChangedMigrations(ctx context.Context, t *time.Time) ([]Migration, error) {
+func (m *mockNovaAPI) GetAllMigrations(ctx context.Context) ([]Migration, error) {
 	return []Migration{{ID: 1}}, nil
 }
 
@@ -234,7 +234,7 @@ func TestNovaSyncer_SyncMigrations(t *testing.T) {
 
 	ctx := t.Context()
 	syncer.Init(ctx)
-	migrations, err := syncer.SyncChangedMigrations(ctx)
+	migrations, err := syncer.SyncAllMigrations(ctx)
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
 	}

From f1df803387fbc81a89cd2d324af23f0770cf239c Mon Sep 17 00:00:00 2001
From: Markus Wieland <markus.wieland@sap.com>
Date: Wed, 1 Oct 2025 17:07:36 +0200
Subject: [PATCH 2/5] Remove unnecessary newline in
 TestNovaAPI_GetAllMigrations

---
 internal/sync/openstack/nova/nova_api_test.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/internal/sync/openstack/nova/nova_api_test.go b/internal/sync/openstack/nova/nova_api_test.go
index 69a11ea8..3be154c3 100644
--- a/internal/sync/openstack/nova/nova_api_test.go
+++ b/internal/sync/openstack/nova/nova_api_test.go
@@ -232,5 +232,4 @@ func TestNovaAPI_GetAllMigrations(t *testing.T) {
 	if migrations[0].ID != 1 || migrations[0].SourceCompute != "host1" || migrations[0].DestCompute != "host2" || migrations[0].Status != "completed" {
 		t.Errorf("unexpected migration data: %+v", migrations[0])
 	}
-
 }

From 64540b6ec64db575a5b38a233d9e8b72591592fd Mon Sep 17 00:00:00 2001
From: Markus Wieland <markus.wieland@sap.com>
Date: Thu, 2 Oct 2025 11:16:24 +0200
Subject: [PATCH 3/5] Lint

---
 .../plugins/shared/vm_host_residency.sql      |  2 +-
 .../vmware/vrops_hostsystem_resolver.sql      |  2 +-
 .../vmware/vrops_project_noisiness.sql        |  2 +-
 internal/sync/openstack/nova/nova_api.go      |  4 ++
 internal/sync/openstack/nova/nova_sync.go     | 37 +++++++------------
 internal/sync/openstack/nova/nova_types.go    |  2 +-
 6 files changed, 21 insertions(+), 28 deletions(-)

diff --git a/internal/extractor/plugins/shared/vm_host_residency.sql b/internal/extractor/plugins/shared/vm_host_residency.sql
index 8ad5188f..9b95f3b0 100644
--- a/internal/extractor/plugins/shared/vm_host_residency.sql
+++ b/internal/extractor/plugins/shared/vm_host_residency.sql
@@ -21,7 +21,7 @@ WITH durations AS (
             )) AS BIGINT)
         ) AS duration
     FROM openstack_migrations AS migrations
-    LEFT JOIN openstack_servers_v2 AS servers ON servers.id = migrations.instance_uuid
+    LEFT JOIN openstack_servers AS servers ON servers.id = migrations.instance_uuid
     LEFT JOIN openstack_flavors_v2 AS flavors ON flavors.name = servers.flavor_name
 )
 SELECT
diff --git a/internal/extractor/plugins/vmware/vrops_hostsystem_resolver.sql b/internal/extractor/plugins/vmware/vrops_hostsystem_resolver.sql
index 8ab0a2c7..e2c6ad4b 100644
--- a/internal/extractor/plugins/vmware/vrops_hostsystem_resolver.sql
+++ b/internal/extractor/plugins/vmware/vrops_hostsystem_resolver.sql
@@ -3,5 +3,5 @@ SELECT DISTINCT
     m.hostsystem AS vrops_hostsystem,
     s.os_ext_srv_attr_host AS nova_compute_host
 FROM vrops_vm_metrics m
-LEFT JOIN openstack_servers_v2 s ON m.instance_uuid = s.id
+LEFT JOIN openstack_servers s ON m.instance_uuid = s.id
 WHERE s.os_ext_srv_attr_host IS NOT NULL;
diff --git a/internal/extractor/plugins/vmware/vrops_project_noisiness.sql b/internal/extractor/plugins/vmware/vrops_project_noisiness.sql
index 0b006779..334668b2 100644
--- a/internal/extractor/plugins/vmware/vrops_project_noisiness.sql
+++ b/internal/extractor/plugins/vmware/vrops_project_noisiness.sql
@@ -19,7 +19,7 @@ host_cpu_usage AS (
         s.tenant_id,
         h.service_host,
         AVG(p.avg_cpu) AS avg_cpu_of_project
-    FROM openstack_servers_v2 s
+    FROM openstack_servers s
     JOIN vrops_vm_metrics m ON s.id = m.instance_uuid
     JOIN projects_avg_cpu p ON s.tenant_id = p.tenant_id
     JOIN openstack_hypervisors h ON s.os_ext_srv_attr_hypervisor_hostname = h.hostname
diff --git a/internal/sync/openstack/nova/nova_api.go b/internal/sync/openstack/nova/nova_api.go
index b339d584..dfcfecee 100644
--- a/internal/sync/openstack/nova/nova_api.go
+++ b/internal/sync/openstack/nova/nova_api.go
@@ -110,6 +110,7 @@ func (api *novaAPI) GetAllServers(ctx context.Context) ([]Server, error) {
 }
 
 // Get all deleted Nova servers.
+// In SAP Cloud Infrastructure nova a deleted server is removed from the database after 3 weeks.
 func (api *novaAPI) GetDeletedServers(ctx context.Context, since time.Time) ([]DeletedServer, error) {
 	label := DeletedServer{}.TableName()
 
@@ -227,6 +228,9 @@ func (api *novaAPI) GetAllFlavors(ctx context.Context) ([]Flavor, error) {
 }
 
 // Get all Nova migrations.
+// Nova calls vm "instance" internally but via the api they are called "server".
+// Nova deletes migrations when a server (instance) is deleted (https://github.com/openstack/nova/blob/1508cb39a2b12ef2d4f706b9c303a744ce40e707/nova/db/main/api.py#L1337-L1358)
+// The nova fork of SAP Cloud Infrastructure does remove deleted migrations after 3 weeks.
 func (api *novaAPI) GetAllMigrations(ctx context.Context) ([]Migration, error) {
 	label := Migration{}.TableName()
 	slog.Info("fetching nova data", "label", label)
diff --git a/internal/sync/openstack/nova/nova_sync.go b/internal/sync/openstack/nova/nova_sync.go
index 494a19c4..e793e952 100644
--- a/internal/sync/openstack/nova/nova_sync.go
+++ b/internal/sync/openstack/nova/nova_sync.go
@@ -60,58 +60,46 @@ func (s *NovaSyncer) Init(ctx context.Context) {
 func (s *NovaSyncer) Sync(ctx context.Context) error {
 	// Only sync the objects that are configured in the yaml conf.
 	if slices.Contains(s.Conf.Types, "servers") {
-		allServers, err := s.SyncAllServers(ctx)
+		_, err := s.SyncAllServers(ctx)
 		if err != nil {
 			return err
 		}
-		if len(allServers) > 0 {
-			go s.MqttClient.Publish(TriggerNovaServersSynced, "")
-		}
+		go s.MqttClient.Publish(TriggerNovaServersSynced, "")
 	}
 	if slices.Contains(s.Conf.Types, "deleted_servers") {
-		deletedServers, err := s.SyncDeletedServers(ctx)
+		_, err := s.SyncDeletedServers(ctx)
 		if err != nil {
 			return err
 		}
-		if len(deletedServers) > 0 {
-			go s.MqttClient.Publish(TriggerNovaDeletedServersSynced, "")
-		}
+		go s.MqttClient.Publish(TriggerNovaDeletedServersSynced, "")
 	}
 	if slices.Contains(s.Conf.Types, "hypervisors") {
-		allHypervisors, err := s.SyncAllHypervisors(ctx)
+		_, err := s.SyncAllHypervisors(ctx)
 		if err != nil {
 			return err
 		}
-		if len(allHypervisors) > 0 {
-			go s.MqttClient.Publish(TriggerNovaHypervisorsSynced, "")
-		}
+		go s.MqttClient.Publish(TriggerNovaHypervisorsSynced, "")
 	}
 	if slices.Contains(s.Conf.Types, "flavors") {
-		allFlavors, err := s.SyncAllFlavors(ctx)
+		_, err := s.SyncAllFlavors(ctx)
 		if err != nil {
 			return err
 		}
-		if len(allFlavors) > 0 {
-			go s.MqttClient.Publish(TriggerNovaFlavorsSynced, "")
-		}
+		go s.MqttClient.Publish(TriggerNovaFlavorsSynced, "")
 	}
 	if slices.Contains(s.Conf.Types, "migrations") {
-		allMigrations, err := s.SyncAllMigrations(ctx)
+		_, err := s.SyncAllMigrations(ctx)
 		if err != nil {
 			return err
 		}
-		if len(allMigrations) > 0 {
-			go s.MqttClient.Publish(TriggerNovaMigrationsSynced, "")
-		}
+		go s.MqttClient.Publish(TriggerNovaMigrationsSynced, "")
 	}
 	if slices.Contains(s.Conf.Types, "aggregates") {
-		allAggregates, err := s.SyncAllAggregates(ctx)
+		_, err := s.SyncAllAggregates(ctx)
 		if err != nil {
 			return err
 		}
-		if len(allAggregates) > 0 {
-			go s.MqttClient.Publish(TriggerNovaAggregatesSynced, "")
-		}
+		go s.MqttClient.Publish(TriggerNovaAggregatesSynced, "")
 	}
 	return nil
 }
@@ -192,6 +180,7 @@ func (s *NovaSyncer) SyncAllMigrations(ctx context.Context) ([]Migration, error)
 	return allMigrations, nil
 }
 
+// Sync the OpenStack aggregates into the database.
 func (s *NovaSyncer) SyncAllAggregates(ctx context.Context) ([]Aggregate, error) {
 	allAggregates, err := s.API.GetAllAggregates(ctx)
 	if err != nil {
diff --git a/internal/sync/openstack/nova/nova_types.go b/internal/sync/openstack/nova/nova_types.go
index ed40cecd..f4fec89c 100644
--- a/internal/sync/openstack/nova/nova_types.go
+++ b/internal/sync/openstack/nova/nova_types.go
@@ -165,7 +165,7 @@ func (s *Server) MarshalJSON() ([]byte, error) {
 }
 
 // Table in which the openstack model is stored.
-func (Server) TableName() string { return "openstack_servers_v2" }
+func (Server) TableName() string { return "openstack_servers" }
 
 // Index for the openstack model.
 func (Server) Indexes() []db.Index { return nil }

From ba9368ed958f86b8e8b6c321b3a9a8cbdeb6f940 Mon Sep 17 00:00:00 2001
From: Markus Wieland <markus.wieland@sap.com>
Date: Thu, 2 Oct 2025 11:23:11 +0200
Subject: [PATCH 4/5] Made comments better

---
 internal/sync/openstack/nova/nova_api.go | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/internal/sync/openstack/nova/nova_api.go b/internal/sync/openstack/nova/nova_api.go
index dfcfecee..38649fe3 100644
--- a/internal/sync/openstack/nova/nova_api.go
+++ b/internal/sync/openstack/nova/nova_api.go
@@ -110,7 +110,11 @@ func (api *novaAPI) GetAllServers(ctx context.Context) ([]Server, error) {
 }
 
 // Get all deleted Nova servers.
-// In SAP Cloud Infrastructure nova a deleted server is removed from the database after 3 weeks.
+// Note on Nova terminology: Nova uses "instance" internally in its database and code,
+// but exposes these as "server" objects through the public API.
+// Server lifecycle and cleanup:
+// - In SAP Cloud Infrastructure's Nova fork, orphaned servers are purged after 3 weeks
+// - This means historical server data is limited to 3 weeks
 func (api *novaAPI) GetDeletedServers(ctx context.Context, since time.Time) ([]DeletedServer, error) {
 	label := DeletedServer{}.TableName()
 
@@ -227,10 +231,16 @@ func (api *novaAPI) GetAllFlavors(ctx context.Context) ([]Flavor, error) {
 	return data.Flavors, nil
 }
 
-// Get all Nova migrations.
-// Nova calls vm "instance" internally but via the api they are called "server".
-// Nova deletes migrations when a server (instance) is deleted (https://github.com/openstack/nova/blob/1508cb39a2b12ef2d4f706b9c303a744ce40e707/nova/db/main/api.py#L1337-L1358)
-// The nova fork of SAP Cloud Infrastructure does remove deleted migrations after 3 weeks.
+// Get all Nova migrations from the OpenStack API.
+//
+// Note on Nova terminology: Nova uses "instance" internally in its database and code,
+// but exposes these as "server" objects through the public API.
+//
+// Migration lifecycle and cleanup:
+//   - Migrations are automatically deleted when their associated server is deleted
+//     (see Nova source: https://github.com/openstack/nova/blob/1508cb39a2b12ef2d4f706b9c303a744ce40e707/nova/db/main/api.py#L1337-L1358)
+//   - In SAP Cloud Infrastructure's Nova fork, orphaned migrations are purged after 3 weeks
+//   - This means historical migration data has limited retention
 func (api *novaAPI) GetAllMigrations(ctx context.Context) ([]Migration, error) {
 	label := Migration{}.TableName()
 	slog.Info("fetching nova data", "label", label)

From b6b3a4690ef29e0b530de7589828e0432d4e7607 Mon Sep 17 00:00:00 2001
From: Markus Wieland <markus.wieland@sap.com>
Date: Thu, 2 Oct 2025 11:23:25 +0200
Subject: [PATCH 5/5] Fix comment indentation for server lifecycle notes in
 GetAllServers function

---
 internal/sync/openstack/nova/nova_api.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/internal/sync/openstack/nova/nova_api.go b/internal/sync/openstack/nova/nova_api.go
index 38649fe3..5552c821 100644
--- a/internal/sync/openstack/nova/nova_api.go
+++ b/internal/sync/openstack/nova/nova_api.go
@@ -113,8 +113,8 @@ func (api *novaAPI) GetAllServers(ctx context.Context) ([]Server, error) {
 // Note on Nova terminology: Nova uses "instance" internally in its database and code,
 // but exposes these as "server" objects through the public API.
 // Server lifecycle and cleanup:
-// - In SAP Cloud Infrastructure's Nova fork, orphaned servers are purged after 3 weeks
-// - This means historical server data is limited to 3 weeks
+//   - In SAP Cloud Infrastructure's Nova fork, orphaned servers are purged after 3 weeks
+//   - This means historical server data is limited to 3 weeks
 func (api *novaAPI) GetDeletedServers(ctx context.Context, since time.Time) ([]DeletedServer, error) {
 	label := DeletedServer{}.TableName()