googleapis/mcp-toolbox · error

failed to open connection: %w

Error message

failed to open connection: %w

What it means

sqlx.Open (via the Trino driver) failed in initTrinoConnectionPool — the DSN built from host/port/user/credentials/catalog/schema was rejected or the Trino coordinator was unreachable.

Source

Thrown at internal/sources/trino/trino.go:197

		return nil, fmt.Errorf("unable to get logger from ctx: %s", err)
	}

	if disableSslVerification {
		logger.WarnContext(ctx, "SSL verification is disabled for trino source %s. This is an insecure setting and should not be used in production.\n", name)
		tr := &http.Transport{
			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
		}
		client := &http.Client{Transport: tr}
		clientName := fmt.Sprintf("insecure_trino_client_%s", name)
		if err := trinogo.RegisterCustomClient(clientName, client); err != nil {
			return nil, fmt.Errorf("failed to register custom client: %w", err)
		}
		dsn = fmt.Sprintf("%s&custom_client=%s", dsn, clientName)
	}

	db, err := sql.Open("trino", dsn)
	if err != nil {
		return nil, fmt.Errorf("failed to open connection: %w", err)
	}

	// Configure connection pool
	db.SetMaxOpenConns(10)
	db.SetMaxIdleConns(5)
	db.SetConnMaxLifetime(time.Hour)

	return db, nil
}

func buildTrinoDSN(host, port, user, password, catalog, schema, queryTimeout, accessToken string, kerberosEnabled, sslEnabled bool, sslCertPath, sslCert string) (string, error) {
	// Build query parameters
	query := url.Values{}
	query.Set("catalog", catalog)
	query.Set("schema", schema)
	if queryTimeout != "" {
		query.Set("queryTimeout", queryTimeout)
	}

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Verify host, port, credentials, catalog and schema in the config
2. Confirm Trino coordinator reachability and TLS settings
3. Check Kerberos/access-token configuration if enabled

When it happens

Trigger: Thrown at internal/sources/trino/trino.go:197 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/31b2cd121f847343. Report an issue: GitHub.