benbjohnson/litestream · error

populate table %s: %w

Error message

populate table %s: %w

What it means

populateDatabase wraps a failure from populateTable for a given test table in this error. After creating tables, each table is filled with rowsPerTable rows in batches; any failure inside populateTable (transaction begin, prepare, insert, commit) is surfaced here with the table name. The remaining tables are not populated and the command exits.

Source

Thrown at cmd/litestream-test/populate.go:143

	totalRows := int(targetBytes / int64(c.RowSize))
	rowsPerTable := totalRows / c.TableCount
	if rowsPerTable == 0 {
		rowsPerTable = 1
	}

	slog.Info("Populating database",
		"target_bytes", targetBytes,
		"total_rows", totalRows,
		"rows_per_table", rowsPerTable,
	)

	startTime := time.Now()
	for tableIdx := 0; tableIdx < c.TableCount; tableIdx++ {
		tableName := fmt.Sprintf("test_table_%d", tableIdx)

		if err := c.populateTable(ctx, db, tableName, rowsPerTable); err != nil {
			return fmt.Errorf("populate table %s: %w", tableName, err)
		}

		currentSize, _ := getDatabaseSize(c.DB)
		progress := float64(currentSize) / float64(targetBytes) * 100
		slog.Info("Progress",
			"table", tableName,
			"current_size_mb", currentSize/1024/1024,
			"progress_percent", fmt.Sprintf("%.1f", progress),
		)

		if currentSize >= targetBytes {
			break
		}
	}

	duration := time.Since(startTime)
	finalSize, _ := getDatabaseSize(c.DB)

View on GitHub (pinned to 4ed7a308f6)

Solutions

1. Inspect the wrapped cause (the insert/commit/begin error) to find the root failure.
2. Check free disk space; SQLite writes fail with SQLITE_FULL when out of space.
3. Reduce target size or RowSize to fit available disk.
4. Ensure no competing process holds a write lock during population.

Example fix

// before
err := c.populateTable(ctx, db, tableName, rowsPerTable) // opaque failure
// after
err := c.populateTable(ctx, db, tableName, rowsPerTable)
if err != nil {
    slog.Error("populate failed", "table", tableName, "cause", errors.Unwrap(err))
}

// preflight: disk space and lock check before population
if fi, err := os.Stat(filepath.Dir(c.DB)); err != nil {
    return fmt.Errorf("db dir unavailable: %w", err)
}
// verify no other writer holds the db
if conn, err := os.OpenFile(c.DB, os.O_RDWR, 0); err != nil {
    return fmt.Errorf("db not writable: %w", err)
} else {
    conn.Close()
}

if err := c.populateTable(ctx, db, tableName, rowsPerTable); err != nil {
    if errors.Is(err, sqlite.ErrBusy) || strings.Contains(err.Error(), "SQLITE_BUSY") {
        time.Sleep(time.Second)
        return c.populateTable(ctx, db, tableName, rowsPerTable) // retry once
    }
    return fmt.Errorf("populate table %s: %w", tableName, err)
}

When it happens

Trigger: populateTable returns an error for table test_table_%d: the batch insert transaction fails to begin, the INSERT statement fails to prepare or execute, or the commit fails. The original cause is available via errors.Unwrap.

Common situations: Disk filling mid-population on a large target size; context cancellation surfacing through a failing database call; locked database from a concurrent reader (e.g. litestream or a monitoring query).

Related errors

• open database: %w
• open database: %w
• set journal mode: %w
• create table %s: %w
• begin transaction: %w

AI-assisted analysis of benbjohnson/litestream@4ed7a308f6 (2026-09-06). Data as JSON: /api/errors/e588bd7dce63f974. Report an issue: GitHub.