vitessio/vitess · error

failed to convert server-id: %v

Error message

failed to convert server-id: %v

What it means

ReadMycnf requires a server-id in the parsed config; the string is fetched via lookupWithDefault and parsed with strconv.ParseUint(base 10, 32 bits). If parsing fails (missing handled earlier, so this fires on non-numeric or out-of-range values), this error wraps the cause.

Source

Thrown at go/vt/mysqlctl/mycnf.go:210

		}
		line = bytes.TrimSpace(line)

		parts = bytes.Split(line, []byte("="))
		if len(parts) < 2 {
			continue
		}
		lval = normKey(parts[0])
		rval = string(bytes.TrimSpace(parts[1]))
		mycnf.mycnfMap[lval] = rval
	}

	serverIDStr, err := mycnf.lookupWithDefault("server-id", "")
	if err != nil {
		return nil, err
	}
	serverID, err := strconv.ParseUint(serverIDStr, 10, 32)
	if err != nil {
		return nil, fmt.Errorf("failed to convert server-id: %v", err)
	}
	mycnf.ServerID = uint32(serverID)

	port, err := mycnf.lookupInt("port")
	if err != nil {
		return nil, err
	}
	mycnf.MysqlPort = port

	mapping := map[string]*string{
		"datadir":                   &mycnf.DataDir,
		"innodb_data_home_dir":      &mycnf.InnodbDataHomeDir,
		"innodb_log_group_home_dir": &mycnf.InnodbLogGroupHomeDir,
		"socket":                    &mycnf.SocketFile,
		"general_log_file":          &mycnf.GeneralLogPath,
		"log-error":                 &mycnf.ErrorLogPath,
		"slow-query-log-file":       &mycnf.SlowLogPath,
		"relay-log":                 &mycnf.RelayLogPath,

View on GitHub (pinned to 01a25a7d17)

Solutions

1. Set server-id to an integer between 1 and 4294967295 in my.cnf.
2. Convert any hex or oversized server-id values to a valid 32-bit decimal.
3. Ensure each replica has a unique server-id in that range before re-running.

Example fix

// before
server-id = 0b9f3a1c-... (uuid)
// after
server-id = 623

v := getCnfValue("server-id")
id, err := strconv.ParseUint(v, 10, 32)
if err != nil { return fmt.Errorf("server-id %q not a uint32: %w", v, err) }
if id == 0 { return errors.New("server-id must be >= 1") }

mycnf, err := mysqlctl.ReadMycnf(path)
if err != nil {
	if strings.Contains(err.Error(), "server-id") { /* fix server-id in config */ }
	return err
}

When it happens

Trigger: ReadMycnf encountering a server-id that is non-numeric or exceeds uint32 (max 4294967295), e.g. a UUID-based server_id from MariaDB configs or a negative value.

Common situations: Copying server-id from MySQL 8.0's UUID-derived values; typos like 'server-id = 0x10' (hex not accepted); value larger than 32 bits from automated generators.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• cannot perform backup without my.cnf, please restart vttable
• value for key '%v' not set and no default value set
• failed to convert %s: %v
• invalid key:value pair
• Last_SQL_Error: ${LastSQL_Error}, Last_IO_Error: ${LastIO_Er

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/b9b0e4e28d9b0386. Report an issue: GitHub.