gastownhall/beads · error

failed to ping server: %w

Error message

failed to ping server: %w

What it means

After opening the connection, runDoltServerDiagnostics pings the Dolt SQL server with a 30-second timeout (db.PingContext). Failure to establish/verify a live connection is wrapped with this message and the underlying driver error.

Source

Thrown at cmd/bd/doctor/perf_dolt.go:146

		TLS:      tls,
	}.String()

	// Measure connection time
	start := time.Now()
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		return fmt.Errorf("failed to open MySQL connection: %w", err)
	}
	defer db.Close()

	// Set connection pool settings
	db.SetMaxOpenConns(5)
	db.SetMaxIdleConns(2)

	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()
	if err := db.PingContext(ctx); err != nil {
		return fmt.Errorf("failed to ping server: %w", err)
	}
	metrics.ConnectionTime = time.Since(start).Milliseconds()

	// Run all diagnostics
	return runDoltDiagnosticQueries(ctx, db, metrics)
}

// runDoltDiagnosticQueries runs the diagnostic queries and populates metrics
func runDoltDiagnosticQueries(ctx context.Context, db *sql.DB, metrics *DoltPerfMetrics) error {
	// Get issue counts
	if err := db.QueryRowContext(ctx, "SELECT COUNT(*) FROM issues").Scan(&metrics.TotalIssues); err != nil {
		return fmt.Errorf("failed to count issues: %w", err)
	}

	if err := db.QueryRowContext(ctx, "SELECT COUNT(*) FROM issues WHERE status != 'closed'").Scan(&metrics.OpenIssues); err != nil {
		metrics.OpenIssues = -1 // Mark as unavailable
	}

View on GitHub (pinned to 71377f2769)

Solutions

1. Confirm dolt sql-server is running and reachable (nc -zv host port)
2. Fix credentials/DSN if the driver reports access denied
3. Increase timeout or check server load/logs if the 30s context deadline is exceeded

Example fix

// before
ctx, _ := context.WithTimeout(context.Background(), 30*time.Second)
// after
if !serverReachable(host, port) { startDoltServer() }
ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)

conn, err := net.DialTimeout("tcp", addr, 2*time.Second); if err != nil { /* server down — start it */ }

if err != nil && strings.Contains(err.Error(), "failed to ping server") {
    // inspect driver error: refused vs access denied vs timeout
    var mysqlErr *mysql.MySQLError
    if errors.As(errors.Unwrap(err), &mysqlErr) { /* handle by code */ }
}

When it happens

Trigger: db.PingContext(ctx) fails: server not listening on host:port (connection refused), auth rejected, TLS mismatch, or the 30s timeout expires on a hung/overloaded server.

Common situations: dolt sql-server stopped between the running-check and connect; wrong credentials in DSN; firewall/Docker networking blocking the port; server overloaded so handshake exceeds 30s.

Understand the failure class

Background: ECONNREFUSED and "connection refused" / "could not connect to server" errors: what they mean and how to fix them — this error's family across 44 libraries.

Related errors

• server not reachable: %w
• dolt server connection failed: %w
• dolt sql-server is not running on %s:%d; start it with 'bd d
• failed to open MySQL connection: %w
• ensure global db: server not reachable: %w

AI-assisted analysis of gastownhall/beads@71377f2769 (2026-08-30). Data as JSON: /api/errors/04642966691e0ddc. Report an issue: GitHub.