gastownhall/beads · warning

flush: failed to list databases: %w

Error message

flush: failed to list databases: %w

What it means

FlushWorkingSet wraps a failure of the 'SHOW DATABASES' query with this message after a successful ping, meaning the connection dropped or the server rejected the query mid-flush. The caller treats the whole flush as failed (best-effort; the stop proceeds with a warning), so uncommitted working-set changes may be lost for that shutdown.

Source

Thrown at internal/doltserver/doltserver.go:1588

		Port: port,
		User: "root",
	}.String()
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		return fmt.Errorf("flush: failed to open connection: %w", err)
	}
	defer db.Close()
	db.SetMaxOpenConns(1)
	db.SetConnMaxLifetime(10 * time.Second)

	if err := db.PingContext(ctx); err != nil {
		return fmt.Errorf("flush: server not reachable: %w", err)
	}

	// List all databases, skipping system databases
	rows, err := db.QueryContext(ctx, "SHOW DATABASES")
	if err != nil {
		return fmt.Errorf("flush: failed to list databases: %w", err)
	}
	var databases []string
	for rows.Next() {
		var name string
		if err := rows.Scan(&name); err != nil {
			continue
		}
		// Skip Dolt system databases
		if name == "information_schema" || name == "mysql" || name == "performance_schema" {
			continue
		}
		databases = append(databases, name)
	}
	_ = rows.Close()

	if len(databases) == 0 {
		return nil
	}

View on GitHub (pinned to 71377f2769)

Solutions

1. Retry bd dolt stop — the error is often transient if the server was mid-restart
2. Confirm only one bd process is managing the server (avoid concurrent stop/start from other terminals or CI jobs)
3. Check the dolt server log for engine errors or connection kills at the failure time
4. If on a remote server, verify network stability (a dropped connection between ping and query produces exactly this error)
5. As a fallback, run explicit dolt commits (cd <data-dir> && dolt add -A && dolt commit -m 'manual flush') to protect uncommitted work

Example fix

// before: concurrent stop/start kills the flush connection
// $ (terminal A) bd dolt stop &  (terminal B) bd dolt restart
// after: serialize server lifecycle operations
// $ bd dolt restart   # single command handles flush + stop + start

// Sanity-check the connection is still usable before the flush queries
conn, err := net.DialTimeout("tcp", net.JoinHostPort(host, strconv.Itoa(port)), 2*time.Second)
if err != nil {
    return fmt.Errorf("server unreachable on %s:%d; aborting flush", host, port)
}
conn.Close()

err := doltserver.FlushWorkingSet(host, port)
if err != nil && strings.Contains(err.Error(), "failed to list databases") {
    // transient drop (restart/limits): one retry, then log and continue best-effort
    time.Sleep(time.Second)
    if err := doltserver.FlushWorkingSet(host, port); err != nil {
        log.Printf("warning: flush failed after retry: %v", err)
    }
}

When it happens

Trigger: db.QueryContext(ctx, "SHOW DATABASES") errors after the ping succeeded: the connection died between ping and query (server restart/crash in that window), the server killed the connection (max connections, idle timeout misconfig), or Dolt returned an engine error enumerating databases.

Common situations: Server being concurrently restarted by another bd process during shutdown; connection-limit exhaustion on a shared server; flaky network to a remote shared server; Dolt version-specific errors on SHOW DATABASES.

Related errors

• ensure global db: failed to create %s: %w
• flush: failed to open connection: %w
• flush: server not reachable: %w
• failed to open server connection: %w
• failed to begin transaction: %w

AI-assisted analysis of gastownhall/beads@71377f2769 (2026-08-30). Data as JSON: /api/errors/23c43d3c9088b889. Report an issue: GitHub.