improve rollup reporting

internal/report/snapshots.go

@@ -6,6 +6,7 @@ import (
 	"database/sql"
 	"fmt"
 	"log/slog"
+	"strconv"
 	"strings"
 	"time"
 	"vctp/db"
@@ -187,6 +188,63 @@ ORDER BY snapshot_time DESC, table_name DESC
 	return records, rows.Err()
 }
 
+func ListSnapshotsByRange(ctx context.Context, database db.Database, snapshotType string, start time.Time, end time.Time) ([]SnapshotRecord, error) {
+	dbConn := database.DB()
+	driver := strings.ToLower(dbConn.DriverName())
+
+	startUnix := start.Unix()
+	endUnix := end.Unix()
+
+	var rows *sqlx.Rows
+	var err error
+
+	switch driver {
+	case "sqlite":
+		rows, err = dbConn.QueryxContext(ctx, `
+SELECT table_name, snapshot_time, snapshot_type
+FROM snapshot_registry
+WHERE snapshot_type = ?
+  AND snapshot_time >= ?
+  AND snapshot_time < ?
+ORDER BY snapshot_time ASC, table_name ASC
+`, snapshotType, startUnix, endUnix)
+	case "pgx", "postgres":
+		rows, err = dbConn.QueryxContext(ctx, `
+SELECT table_name, snapshot_time, snapshot_type
+FROM snapshot_registry
+WHERE snapshot_type = $1
+  AND snapshot_time >= $2
+  AND snapshot_time < $3
+ORDER BY snapshot_time ASC, table_name ASC
+`, snapshotType, startUnix, endUnix)
+	default:
+		return nil, fmt.Errorf("unsupported driver for listing snapshots: %s", driver)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	records := make([]SnapshotRecord, 0)
+	for rows.Next() {
+		var (
+			tableName    string
+			snapshotTime int64
+			recordType   string
+		)
+		if err := rows.Scan(&tableName, &snapshotTime, &recordType); err != nil {
+			return nil, err
+		}
+		records = append(records, SnapshotRecord{
+			TableName:    tableName,
+			SnapshotTime: time.Unix(snapshotTime, 0),
+			SnapshotType: recordType,
+		})
+	}
+	return records, rows.Err()
+}
+
 func FormatSnapshotLabel(snapshotType string, snapshotTime time.Time, tableName string) string {
 	switch snapshotType {
 	case "hourly":
@@ -214,6 +272,23 @@ func CreateTableReport(logger *slog.Logger, Database db.Database, ctx context.Co
 		return nil, fmt.Errorf("no columns found for table %s", tableName)
 	}
 
+	humanizeTimes := strings.HasPrefix(tableName, "inventory_daily_summary_") || strings.HasPrefix(tableName, "inventory_monthly_summary_")
+	type columnSpec struct {
+		Name        string
+		SourceIndex int
+		Humanize    bool
+	}
+	specs := make([]columnSpec, 0, len(columns)+2)
+	for i, columnName := range columns {
+		specs = append(specs, columnSpec{Name: columnName, SourceIndex: i})
+		if humanizeTimes && columnName == "CreationTime" {
+			specs = append(specs, columnSpec{Name: "CreationTimeReadable", SourceIndex: i, Humanize: true})
+		}
+		if humanizeTimes && columnName == "DeletionTime" {
+			specs = append(specs, columnSpec{Name: "DeletionTimeReadable", SourceIndex: i, Humanize: true})
+		}
+	}
+
 	query := fmt.Sprintf(`SELECT * FROM %s`, tableName)
 	orderBy := snapshotOrderBy(columns)
 	if orderBy != "" {
@@ -240,12 +315,12 @@ func CreateTableReport(logger *slog.Logger, Database db.Database, ctx context.Co
 		logger.Error("Error setting document properties", "error", err, "sheet_name", sheetName)
 	}
 
-	for i, columnName := range columns {
+	for i, spec := range specs {
 		cell := fmt.Sprintf("%s1", string(rune('A'+i)))
-		xlsx.SetCellValue(sheetName, cell, columnName)
+		xlsx.SetCellValue(sheetName, cell, spec.Name)
 	}
 
-	if endCell, err := excelize.CoordinatesToCellName(len(columns), 1); err == nil {
+	if endCell, err := excelize.CoordinatesToCellName(len(specs), 1); err == nil {
 		filterRange := "A1:" + endCell
 		if err := xlsx.AutoFilter(sheetName, filterRange, nil); err != nil {
 			logger.Error("Error setting autofilter", "error", err)
@@ -269,9 +344,14 @@ func CreateTableReport(logger *slog.Logger, Database db.Database, ctx context.Co
 		if err != nil {
 			return nil, err
 		}
-		for colIndex, value := range values {
+		for colIndex, spec := range specs {
 			cell := fmt.Sprintf("%s%d", string(rune('A'+colIndex)), rowIndex)
-			xlsx.SetCellValue(sheetName, cell, normalizeCellValue(value))
+			value := values[spec.SourceIndex]
+			if spec.Humanize {
+				xlsx.SetCellValue(sheetName, cell, formatEpochHuman(value))
+			} else {
+				xlsx.SetCellValue(sheetName, cell, normalizeCellValue(value))
+			}
 		}
 		rowIndex++
 	}
@@ -410,3 +490,37 @@ func normalizeCellValue(value interface{}) interface{} {
 		return v
 	}
 }
+
+func formatEpochHuman(value interface{}) string {
+	var epoch int64
+	switch v := value.(type) {
+	case nil:
+		return ""
+	case int64:
+		epoch = v
+	case int32:
+		epoch = int64(v)
+	case int:
+		epoch = int64(v)
+	case float64:
+		epoch = int64(v)
+	case []byte:
+		parsed, err := strconv.ParseInt(string(v), 10, 64)
+		if err != nil {
+			return ""
+		}
+		epoch = parsed
+	case string:
+		parsed, err := strconv.ParseInt(v, 10, 64)
+		if err != nil {
+			return ""
+		}
+		epoch = parsed
+	default:
+		return ""
+	}
+	if epoch <= 0 {
+		return ""
+	}
+	return time.Unix(epoch, 0).Local().Format("Mon 02 Jan 2006 15:04:05 MST")
+}

internal/settings/settings.go

@@ -36,6 +36,7 @@ type SettingsYML struct {
 		VcenterInventoryPollingSeconds   int      `yaml:"vcenter_inventory_polling_seconds"`
 		VcenterInventorySnapshotSeconds  int      `yaml:"vcenter_inventory_snapshot_seconds"`
 		VcenterInventoryAggregateSeconds int      `yaml:"vcenter_inventory_aggregate_seconds"`
+		HourlySnapshotConcurrency        int      `yaml:"hourly_snapshot_concurrency"`
 		HourlySnapshotMaxAgeDays         int      `yaml:"hourly_snapshot_max_age_days"`
 		DailySnapshotMaxAgeMonths        int      `yaml:"daily_snapshot_max_age_months"`
 		SnapshotCleanupCron              string   `yaml:"snapshot_cleanup_cron"`

internal/tasks/inventorySnapshots.go

@@ -5,7 +5,10 @@ import (
 	"database/sql"
 	"fmt"
 	"log/slog"
+	"strconv"
 	"strings"
+	"sync"
+	"sync/atomic"
 	"time"
 	"vctp/db/queries"
 	"vctp/internal/report"
@@ -63,124 +66,33 @@ func (c *CronTask) RunVcenterSnapshotHourly(ctx context.Context, logger *slog.Lo
 	// reload settings in case vcenter list has changed
 	c.Settings.ReadYMLSettings()
 
+	var wg sync.WaitGroup
+	var errCount int64
+	concurrencyLimit := c.Settings.Values.Settings.HourlySnapshotConcurrency
+	var sem chan struct{}
+	if concurrencyLimit > 0 {
+		sem = make(chan struct{}, concurrencyLimit)
+	}
 	for _, url := range c.Settings.Values.Settings.VcenterAddresses {
-		c.Logger.Debug("connecting to vcenter for hourly snapshot", "url", url)
-		vc := vcenter.New(c.Logger, c.VcCreds)
-		if err := vc.Login(url); err != nil {
-			c.Logger.Error("unable to connect to vcenter for hourly snapshot", "error", err, "url", url)
-			continue
+		url := url
+		if sem != nil {
+			sem <- struct{}{}
 		}
-
-		vcVms, err := vc.GetAllVmReferences()
-		if err != nil {
-			c.Logger.Error("unable to get VMs from vcenter", "error", err, "url", url)
-			vc.Logout()
-			continue
-		}
-		canDetectMissing := len(vcVms) > 0
-		if !canDetectMissing {
-			c.Logger.Warn("no VMs returned from vcenter; skipping missing VM detection", "url", url)
-		}
-
-		inventoryRows, err := c.Database.Queries().GetInventoryByVcenter(ctx, url)
-		if err != nil {
-			c.Logger.Error("unable to query inventory table", "error", err, "url", url)
-			vc.Logout()
-			continue
-		}
-
-		inventoryByVmID := make(map[string]queries.Inventory, len(inventoryRows))
-		for _, inv := range inventoryRows {
-			if inv.VmId.Valid {
-				inventoryByVmID[inv.VmId.String] = inv
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			if sem != nil {
+				defer func() { <-sem }()
 			}
-		}
-
-		presentSnapshots := make(map[string]inventorySnapshotRow, len(vcVms))
-		totals := snapshotTotals{}
-		for _, vm := range vcVms {
-			if strings.HasPrefix(vm.Name(), "vCLS-") {
-				continue
+			if err := c.captureHourlySnapshotForVcenter(ctx, startTime, tableName, url); err != nil {
+				atomic.AddInt64(&errCount, 1)
+				c.Logger.Error("hourly snapshot failed", "error", err, "url", url)
 			}
-
-			vmObj, err := vc.ConvertObjToMoVM(vm)
-			if err != nil {
-				c.Logger.Error("failed to read VM details", "vm_id", vm.Reference().Value, "error", err)
-				continue
-			}
-			if vmObj.Config != nil && vmObj.Config.Template {
-				continue
-			}
-
-			var inv *queries.Inventory
-			if existing, ok := inventoryByVmID[vm.Reference().Value]; ok {
-				existingCopy := existing
-				inv = &existingCopy
-			}
-
-			row, err := snapshotFromVM(vmObj, vc, startTime, inv)
-			if err != nil {
-				c.Logger.Error("unable to build snapshot for VM", "vm_id", vm.Reference().Value, "error", err)
-				continue
-			}
-			row.IsPresent = "TRUE"
-			presentSnapshots[vm.Reference().Value] = row
-
-			totals.VmCount++
-			totals.VcpuTotal += nullInt64ToInt(row.VcpuCount)
-			totals.RamTotal += nullInt64ToInt(row.RamGB)
-			totals.DiskTotal += nullFloat64ToFloat(row.ProvisionedDisk)
-		}
-
-		for _, row := range presentSnapshots {
-			if err := insertDailyInventoryRow(ctx, dbConn, tableName, row); err != nil {
-				c.Logger.Error("failed to insert hourly snapshot", "error", err, "vm_id", row.VmId.String)
-			}
-		}
-
-		if !canDetectMissing {
-			vc.Logout()
-			continue
-		}
-
-		for _, inv := range inventoryRows {
-			if strings.HasPrefix(inv.Name, "vCLS-") {
-				continue
-			}
-			vmID := inv.VmId.String
-			if vmID != "" {
-				if _, ok := presentSnapshots[vmID]; ok {
-					continue
-				}
-			}
-
-			row := snapshotFromInventory(inv, startTime)
-			row.IsPresent = "FALSE"
-			if !row.DeletionTime.Valid {
-				deletionTime := startTime.Unix()
-				row.DeletionTime = sql.NullInt64{Int64: deletionTime, Valid: true}
-				if err := c.Database.Queries().InventoryMarkDeleted(ctx, queries.InventoryMarkDeletedParams{
-					DeletionTime:   row.DeletionTime,
-					VmId:           inv.VmId,
-					DatacenterName: inv.Datacenter,
-				}); err != nil {
-					c.Logger.Warn("failed to mark inventory record deleted", "error", err, "vm_id", row.VmId.String)
-				}
-			}
-			if err := insertDailyInventoryRow(ctx, dbConn, tableName, row); err != nil {
-				c.Logger.Error("failed to insert missing VM snapshot", "error", err, "vm_id", row.VmId.String)
-			}
-		}
-
-		vc.Logout()
-
-		c.Logger.Info("Hourly snapshot summary",
-			"vcenter", url,
-			"vm_count", totals.VmCount,
-			"vcpu_total", totals.VcpuTotal,
-			"ram_total_gb", totals.RamTotal,
-			"disk_total_gb", totals.DiskTotal,
-		)
+		}()
+	}
+	wg.Wait()
+	if errCount > 0 {
+		return fmt.Errorf("hourly snapshot failed for %d vcenter(s)", errCount)
 	}
 
 	c.Logger.Debug("Finished hourly vcenter snapshot")
@@ -190,10 +102,8 @@ func (c *CronTask) RunVcenterSnapshotHourly(ctx context.Context, logger *slog.Lo
 // RunVcenterDailyAggregate summarizes hourly snapshots into a daily summary table.
 func (c *CronTask) RunVcenterDailyAggregate(ctx context.Context, logger *slog.Logger) error {
 	targetTime := time.Now().Add(-time.Minute)
-	sourceTable, err := hourlyInventoryTableName(targetTime)
-	if err != nil {
-		return err
-	}
+	dayStart := time.Date(targetTime.Year(), targetTime.Month(), targetTime.Day(), 0, 0, 0, 0, targetTime.Location())
+	dayEnd := dayStart.AddDate(0, 0, 1)
 	summaryTable, err := dailySummaryTableName(targetTime)
 	if err != nil {
 		return err
@@ -206,13 +116,38 @@ func (c *CronTask) RunVcenterDailyAggregate(ctx context.Context, logger *slog.Lo
 	if err := report.EnsureSnapshotRegistry(ctx, c.Database); err != nil {
 		return err
 	}
+	if rowsExist, err := tableHasRows(ctx, dbConn, summaryTable); err != nil {
+		return err
+	} else if rowsExist {
+		c.Logger.Debug("Daily summary already exists, skipping aggregation", "summary_table", summaryTable)
+		return nil
+	}
 
-	currentTotals, err := snapshotTotalsForTable(ctx, dbConn, sourceTable)
+	hourlySnapshots, err := report.ListSnapshotsByRange(ctx, c.Database, "hourly", dayStart, dayEnd)
 	if err != nil {
-		c.Logger.Warn("unable to calculate daily totals", "error", err, "table", sourceTable)
+		return err
+	}
+	if len(hourlySnapshots) == 0 {
+		return fmt.Errorf("no hourly snapshot tables found for %s", dayStart.Format("2006-01-02"))
+	}
+
+	hourlyTables := make([]string, 0, len(hourlySnapshots))
+	for _, snapshot := range hourlySnapshots {
+		hourlyTables = append(hourlyTables, snapshot.TableName)
+	}
+	unionQuery := buildUnionQuery(hourlyTables, []string{
+		`"InventoryId"`, `"Name"`, `"Vcenter"`, `"VmId"`, `"EventKey"`, `"CloudId"`, `"CreationTime"`,
+		`"DeletionTime"`, `"ResourcePool"`, `"VmType"`, `"Datacenter"`, `"Cluster"`, `"Folder"`,
+		`"ProvisionedDisk"`, `"VcpuCount"`, `"RamGB"`, `"IsTemplate"`, `"PoweredOn"`,
+		`"SrmPlaceholder"`, `"VmUuid"`, `"IsPresent"`,
+	})
+
+	currentTotals, err := snapshotTotalsForUnion(ctx, dbConn, unionQuery)
+	if err != nil {
+		c.Logger.Warn("unable to calculate daily totals", "error", err, "date", dayStart.Format("2006-01-02"))
 	} else {
 		c.Logger.Info("Daily snapshot totals",
-			"table", sourceTable,
+			"date", dayStart.Format("2006-01-02"),
 			"vm_count", currentTotals.VmCount,
 			"vcpu_total", currentTotals.VcpuTotal,
 			"ram_total_gb", currentTotals.RamTotal,
@@ -220,15 +155,27 @@ func (c *CronTask) RunVcenterDailyAggregate(ctx context.Context, logger *slog.Lo
 		)
 	}
 
-	prevTable, _ := hourlyInventoryTableName(targetTime.AddDate(0, 0, -1))
-	if prevTable != "" && tableExists(ctx, dbConn, prevTable) {
-		prevTotals, err := snapshotTotalsForTable(ctx, dbConn, prevTable)
+	prevStart := dayStart.AddDate(0, 0, -1)
+	prevEnd := dayStart
+	prevSnapshots, err := report.ListSnapshotsByRange(ctx, c.Database, "hourly", prevStart, prevEnd)
+	if err == nil && len(prevSnapshots) > 0 {
+		prevTables := make([]string, 0, len(prevSnapshots))
+		for _, snapshot := range prevSnapshots {
+			prevTables = append(prevTables, snapshot.TableName)
+		}
+		prevUnion := buildUnionQuery(prevTables, []string{
+			`"InventoryId"`, `"Name"`, `"Vcenter"`, `"VmId"`, `"EventKey"`, `"CloudId"`, `"CreationTime"`,
+			`"DeletionTime"`, `"ResourcePool"`, `"VmType"`, `"Datacenter"`, `"Cluster"`, `"Folder"`,
+			`"ProvisionedDisk"`, `"VcpuCount"`, `"RamGB"`, `"IsTemplate"`, `"PoweredOn"`,
+			`"SrmPlaceholder"`, `"VmUuid"`, `"IsPresent"`,
+		})
+		prevTotals, err := snapshotTotalsForUnion(ctx, dbConn, prevUnion)
 		if err != nil {
-			c.Logger.Warn("unable to calculate previous day totals", "error", err, "table", prevTable)
+			c.Logger.Warn("unable to calculate previous day totals", "error", err, "date", prevStart.Format("2006-01-02"))
 		} else {
 			c.Logger.Info("Daily snapshot comparison",
-				"current_table", sourceTable,
-				"previous_table", prevTable,
+				"current_date", dayStart.Format("2006-01-02"),
+				"previous_date", prevStart.Format("2006-01-02"),
 				"vm_delta", currentTotals.VmCount-prevTotals.VmCount,
 				"vcpu_delta", currentTotals.VcpuTotal-prevTotals.VcpuTotal,
 				"ram_delta_gb", currentTotals.RamTotal-prevTotals.RamTotal,
@@ -262,22 +209,24 @@ SELECT
     / NULLIF(SUM(CASE WHEN "IsPresent" = 'TRUE' THEN 1 ELSE 0 END), 0) AS "PoolSilverPct",
   100.0 * SUM(CASE WHEN "IsPresent" = 'TRUE' AND LOWER("ResourcePool") = 'gold' THEN 1 ELSE 0 END)
     / NULLIF(SUM(CASE WHEN "IsPresent" = 'TRUE' THEN 1 ELSE 0 END), 0) AS "PoolGoldPct"
-FROM %s
+FROM (
+%s
+) snapshots
 GROUP BY
   "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
   "ResourcePool", "VmType", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
   "RamGB", "IsTemplate", "PoweredOn", "SrmPlaceholder", "VmUuid";
-`, summaryTable, sourceTable)
+`, summaryTable, unionQuery)
 
 	if _, err := dbConn.ExecContext(ctx, insertQuery); err != nil {
-		c.Logger.Error("failed to aggregate daily inventory", "error", err, "source_table", sourceTable)
+		c.Logger.Error("failed to aggregate daily inventory", "error", err, "date", dayStart.Format("2006-01-02"))
 		return err
 	}
-	if err := report.RegisterSnapshot(ctx, c.Database, "daily", summaryTable, targetTime); err != nil {
+	if err := report.RegisterSnapshot(ctx, c.Database, "daily", summaryTable, dayStart); err != nil {
 		c.Logger.Warn("failed to register daily snapshot", "error", err, "table", summaryTable)
 	}
 
-	c.Logger.Debug("Finished daily inventory aggregation", "source_table", sourceTable, "summary_table", summaryTable)
+	c.Logger.Debug("Finished daily inventory aggregation", "summary_table", summaryTable)
 	return nil
 }
 
@@ -287,13 +236,18 @@ func (c *CronTask) RunVcenterMonthlyAggregate(ctx context.Context, logger *slog.
 	firstOfThisMonth := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
 	targetMonth := firstOfThisMonth.AddDate(0, -1, 0)
 
-	monthPrefix := fmt.Sprintf("inventory_hourly_%s", targetMonth.Format("200601"))
-	dailyTables, err := report.ListTablesByPrefix(ctx, c.Database, monthPrefix)
+	if err := report.EnsureSnapshotRegistry(ctx, c.Database); err != nil {
+		return err
+	}
+
+	monthStart := time.Date(targetMonth.Year(), targetMonth.Month(), 1, 0, 0, 0, 0, targetMonth.Location())
+	monthEnd := monthStart.AddDate(0, 1, 0)
+	dailySnapshots, err := report.ListSnapshotsByRange(ctx, c.Database, "hourly", monthStart, monthEnd)
 	if err != nil {
 		return err
 	}
-	if len(dailyTables) == 0 {
-		return fmt.Errorf("no daily snapshot tables found for %s", targetMonth.Format("2006-01"))
+	if len(dailySnapshots) == 0 {
+		return fmt.Errorf("no hourly snapshot tables found for %s", targetMonth.Format("2006-01"))
 	}
 
 	monthlyTable, err := monthlySummaryTableName(targetMonth)
@@ -305,10 +259,17 @@ func (c *CronTask) RunVcenterMonthlyAggregate(ctx context.Context, logger *slog.
 	if err := ensureMonthlySummaryTable(ctx, dbConn, monthlyTable); err != nil {
 		return err
 	}
-	if err := report.EnsureSnapshotRegistry(ctx, c.Database); err != nil {
+	if rowsExist, err := tableHasRows(ctx, dbConn, monthlyTable); err != nil {
 		return err
+	} else if rowsExist {
+		c.Logger.Debug("Monthly summary already exists, skipping aggregation", "summary_table", monthlyTable)
+		return nil
 	}
 
+	dailyTables := make([]string, 0, len(dailySnapshots))
+	for _, snapshot := range dailySnapshots {
+		dailyTables = append(dailyTables, snapshot.TableName)
+	}
 	unionQuery := buildUnionQuery(dailyTables, []string{
 		`"InventoryId"`, `"Name"`, `"Vcenter"`, `"VmId"`, `"EventKey"`, `"CloudId"`, `"CreationTime"`,
 		`"DeletionTime"`, `"ResourcePool"`, `"VmType"`, `"Datacenter"`, `"Cluster"`, `"Folder"`,
@@ -398,7 +359,7 @@ func (c *CronTask) RunSnapshotCleanup(ctx context.Context, logger *slog.Logger)
 		if strings.HasPrefix(table, "inventory_daily_summary_") {
 			continue
 		}
-		tableDate, ok := parseSnapshotDate(table, "inventory_hourly_", "2006010215")
+		tableDate, ok := parseSnapshotDate(table, "inventory_hourly_", "epoch")
 		if !ok {
 			continue
 		}
@@ -446,7 +407,7 @@ func (c *CronTask) RunSnapshotCleanup(ctx context.Context, logger *slog.Logger)
 }
 
 func hourlyInventoryTableName(t time.Time) (string, error) {
-	return safeTableName(fmt.Sprintf("inventory_hourly_%s", t.Format("2006010215")))
+	return safeTableName(fmt.Sprintf("inventory_hourly_%d", t.Unix()))
 }
 
 func dailySummaryTableName(t time.Time) (string, error) {
@@ -617,6 +578,13 @@ func parseSnapshotDate(table string, prefix string, layout string) (time.Time, b
 		return time.Time{}, false
 	}
 	suffix := strings.TrimPrefix(table, prefix)
+	if layout == "epoch" {
+		epoch, err := strconv.ParseInt(suffix, 10, 64)
+		if err != nil {
+			return time.Time{}, false
+		}
+		return time.Unix(epoch, 0), true
+	}
 	parsed, err := time.Parse(layout, suffix)
 	if err != nil {
 		return time.Time{}, false
@@ -636,6 +604,21 @@ func dropSnapshotTable(ctx context.Context, dbConn *sqlx.DB, table string) error
 	return err
 }
 
+func tableHasRows(ctx context.Context, dbConn *sqlx.DB, table string) (bool, error) {
+	if _, err := safeTableName(table); err != nil {
+		return false, err
+	}
+	query := fmt.Sprintf(`SELECT 1 FROM %s LIMIT 1`, table)
+	var exists int
+	if err := dbConn.GetContext(ctx, &exists, query); err != nil {
+		if err == sql.ErrNoRows {
+			return false, nil
+		}
+		return false, err
+	}
+	return true, nil
+}
+
 type snapshotTotals struct {
 	VmCount   int64
 	VcpuTotal int64
@@ -938,6 +921,128 @@ VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);
 	return err
 }
 
+func (c *CronTask) captureHourlySnapshotForVcenter(ctx context.Context, startTime time.Time, tableName string, url string) error {
+	c.Logger.Debug("connecting to vcenter for hourly snapshot", "url", url)
+	vc := vcenter.New(c.Logger, c.VcCreds)
+	if err := vc.Login(url); err != nil {
+		return fmt.Errorf("unable to connect to vcenter: %w", err)
+	}
+	defer vc.Logout()
+
+	vcVms, err := vc.GetAllVmReferences()
+	if err != nil {
+		return fmt.Errorf("unable to get VMs from vcenter: %w", err)
+	}
+	canDetectMissing := len(vcVms) > 0
+	if !canDetectMissing {
+		c.Logger.Warn("no VMs returned from vcenter; skipping missing VM detection", "url", url)
+	}
+
+	inventoryRows, err := c.Database.Queries().GetInventoryByVcenter(ctx, url)
+	if err != nil {
+		return fmt.Errorf("unable to query inventory table: %w", err)
+	}
+
+	inventoryByVmID := make(map[string]queries.Inventory, len(inventoryRows))
+	for _, inv := range inventoryRows {
+		if inv.VmId.Valid {
+			inventoryByVmID[inv.VmId.String] = inv
+		}
+	}
+
+	dbConn := c.Database.DB()
+	presentSnapshots := make(map[string]inventorySnapshotRow, len(vcVms))
+	totals := snapshotTotals{}
+	for _, vm := range vcVms {
+		if strings.HasPrefix(vm.Name(), "vCLS-") {
+			continue
+		}
+
+		vmObj, err := vc.ConvertObjToMoVM(vm)
+		if err != nil {
+			c.Logger.Error("failed to read VM details", "vm_id", vm.Reference().Value, "error", err)
+			continue
+		}
+		if vmObj.Config != nil && vmObj.Config.Template {
+			continue
+		}
+
+		var inv *queries.Inventory
+		if existing, ok := inventoryByVmID[vm.Reference().Value]; ok {
+			existingCopy := existing
+			inv = &existingCopy
+		}
+
+		row, err := snapshotFromVM(vmObj, vc, startTime, inv)
+		if err != nil {
+			c.Logger.Error("unable to build snapshot for VM", "vm_id", vm.Reference().Value, "error", err)
+			continue
+		}
+		row.IsPresent = "TRUE"
+		presentSnapshots[vm.Reference().Value] = row
+
+		totals.VmCount++
+		totals.VcpuTotal += nullInt64ToInt(row.VcpuCount)
+		totals.RamTotal += nullInt64ToInt(row.RamGB)
+		totals.DiskTotal += nullFloat64ToFloat(row.ProvisionedDisk)
+	}
+
+	for _, row := range presentSnapshots {
+		if err := insertDailyInventoryRow(ctx, dbConn, tableName, row); err != nil {
+			c.Logger.Error("failed to insert hourly snapshot", "error", err, "vm_id", row.VmId.String)
+		}
+	}
+
+	if !canDetectMissing {
+		c.Logger.Info("Hourly snapshot summary",
+			"vcenter", url,
+			"vm_count", totals.VmCount,
+			"vcpu_total", totals.VcpuTotal,
+			"ram_total_gb", totals.RamTotal,
+			"disk_total_gb", totals.DiskTotal,
+		)
+		return nil
+	}
+
+	for _, inv := range inventoryRows {
+		if strings.HasPrefix(inv.Name, "vCLS-") {
+			continue
+		}
+		vmID := inv.VmId.String
+		if vmID != "" {
+			if _, ok := presentSnapshots[vmID]; ok {
+				continue
+			}
+		}
+
+		row := snapshotFromInventory(inv, startTime)
+		row.IsPresent = "FALSE"
+		if !row.DeletionTime.Valid {
+			deletionTime := startTime.Unix()
+			row.DeletionTime = sql.NullInt64{Int64: deletionTime, Valid: true}
+			if err := c.Database.Queries().InventoryMarkDeleted(ctx, queries.InventoryMarkDeletedParams{
+				DeletionTime:   row.DeletionTime,
+				VmId:           inv.VmId,
+				DatacenterName: inv.Datacenter,
+			}); err != nil {
+				c.Logger.Warn("failed to mark inventory record deleted", "error", err, "vm_id", row.VmId.String)
+			}
+		}
+		if err := insertDailyInventoryRow(ctx, dbConn, tableName, row); err != nil {
+			c.Logger.Error("failed to insert missing VM snapshot", "error", err, "vm_id", row.VmId.String)
+		}
+	}
+
+	c.Logger.Info("Hourly snapshot summary",
+		"vcenter", url,
+		"vm_count", totals.VmCount,
+		"vcpu_total", totals.VcpuTotal,
+		"ram_total_gb", totals.RamTotal,
+		"disk_total_gb", totals.DiskTotal,
+	)
+	return nil
+}
+
 func boolStringFromInterface(value interface{}) string {
 	switch v := value.(type) {
 	case nil:

src/vctp.yml

@@ -15,6 +15,7 @@ settings:
   vcenter_inventory_polling_seconds: 7200
   vcenter_inventory_snapshot_seconds: 3600
   vcenter_inventory_aggregate_seconds: 86400
+  hourly_snapshot_concurrency: 0
   hourly_snapshot_max_age_days: 60
   daily_snapshot_max_age_months: 12
   snapshot_cleanup_cron: "30 2 * * *"