benbjohnson/litestream · warning

get final size: %w

Error message

get final size: %w

What it means

At the end of shrinkDatabase, the final database size is measured with getDatabaseSize(c.DB) to compute the reduction percentage; failure is wrapped as `get final size: %w`. This is a pure filesystem/stat operation — all SQL work (deletes, checkpoint, vacuum) has already completed, so this error never means the shrink itself failed.

Source

Thrown at cmd/litestream-test/shrink.go:134

			"change_from_delete_mb", (sizeAfterDelete-sizeAfterCheckpoint)/1024/1024,
		)
	}

	if c.Vacuum {
		if err := c.runVacuum(db); err != nil {
			return fmt.Errorf("vacuum: %w", err)
		}

		sizeAfterVacuum, _ := getDatabaseSize(c.DB)
		slog.Info("Size after VACUUM",
			"size_mb", sizeAfterVacuum/1024/1024,
			"total_reduction_mb", (initialSize-sizeAfterVacuum)/1024/1024,
		)
	}

	finalSize, err := getDatabaseSize(c.DB)
	if err != nil {
		return fmt.Errorf("get final size: %w", err)
	}

	reductionPercent := float64(initialSize-finalSize) / float64(initialSize) * 100
	slog.Info("Shrink operation complete",
		"initial_size_mb", initialSize/1024/1024,
		"final_size_mb", finalSize/1024/1024,
		"reduction_percent", fmt.Sprintf("%.1f", reductionPercent),
	)

	return nil
}

func (c *ShrinkCommand) getTableList(db *sql.DB) ([]string, error) {
	rows, err := db.Query(`
		SELECT name FROM sqlite_master
		WHERE type='table'
		AND name NOT LIKE 'sqlite_%'
		AND name NOT LIKE 'load_test'

View on GitHub (pinned to 4ed7a308f6)

Solutions

1. Re-run to get a clean summary; the shrink work itself already succeeded
2. Verify with `ls -l <db>` / `du -h <db>` to get the final size manually
3. Prevent cleanup jobs from racing the tool (delay deletion until the process exits)
4. Inspect the wrapped inner error for the exact filesystem cause

// size can always be obtained manually if the tool's final stat fails:
// ls -l <db>  or  sqlite3 <db> 'PRAGMA page_count * page_size;'

if err := runShrink(args); err != nil {
    if strings.Contains(err.Error(), "get final size") {
        log.Printf("shrink completed but final measurement failed (non-fatal): %v", err)
        return nil // work is done; only reporting failed
    }
    return err
}

When it happens

Trigger: The database file vanished or became unreadable between the last operation and this final stat (external deletion, unmounted volume, permissions change); an OS error inside getDatabaseSize.

Common situations: Cleanup automation firing at job completion and deleting temp databases before the tool logs its summary; tests running on ephemeral storage that gets recycled; a hung NFS mount timing out on the final stat.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• get initial size: %w
• get size after delete: %w
• database does not exist: %w
• cannot access SQLite sidecar path: %w
• remove existing output path: %w

AI-assisted analysis of benbjohnson/litestream@4ed7a308f6 (2026-09-06). Data as JSON: /api/errors/09bc0603853ebe00. Report an issue: GitHub.