What causes "base_sleep_time_ms must be non-negative" in t8y2/dbx?

Set base_sleep_time_ms to a non-negative value (e.g. 100-1000ms is typical)

base_sleep_time_ms must be non-negative

Error message

base_sleep_time_ms must be non-negative

What it means

openClient validates retry tuning parameters; base_sleep_time_ms seeds the exponential backoff between ZooKeeper connection retries and must be >= 0. A negative pointer-dereferenced value is rejected with this error.

Source

Thrown at agents/drivers/zookeeper/connection.go:166

func openClient(config connectionConfig) (*clientSession, error) {
	if hasTLSOptions(config) {
		return nil, errors.New("ZooKeeper TLS is not supported")
	}
	authScheme := resolveAuthScheme(config)
	if authScheme != defaultAuthScheme && authScheme != saslDigestAuthScheme {
		return nil, fmt.Errorf("Unsupported auth_scheme %q; expected %q or %q", authScheme, defaultAuthScheme, saslDigestAuthScheme)
	}
	if authScheme == saslDigestAuthScheme {
		if strings.TrimSpace(config.Username) == "" {
			return nil, errors.New(`username is required when auth_scheme = "sasl_digest"`)
		}
		if config.Password == "" {
			return nil, errors.New(`password is required when auth_scheme = "sasl_digest"`)
		}
	}
	if config.BaseSleepTimeMS != nil && *config.BaseSleepTimeMS < 0 {
		return nil, errors.New("base_sleep_time_ms must be non-negative")
	}
	if config.MaxRetries != nil && *config.MaxRetries < 0 {
		return nil, errors.New("max_retries must be non-negative")
	}
	maxBufferSize, err := resolveMaxBufferSize(config)
	if err != nil {
		return nil, err
	}

	target, err := parseConnectTarget(connectionString(config))
	if err != nil {
		return nil, err
	}
	connectionTimeout := millisecondsOrDefault(config.ConnectionTimeoutMS, defaultConnectionTimeout)
	probeTimeout := minDuration(defaultProbeTimeout, connectionTimeout)
	if err := requireReachableServer(target.Servers, probeTimeout); err != nil {
		return nil, err
	}

View on GitHub (pinned to c0390bff16)

Solutions

Set base_sleep_time_ms to a non-negative value (e.g. 100-1000ms is typical)
Leave base_sleep_time_ms unset (nil) to use the driver default
Audit the code computing the value for underflow/sign errors
Remember max_retries retries use roughly base * 2^attempt backoff

Example fix

// before
base := -1 // sentinel for "auto"
cfg := connectionConfig{BaseSleepTimeMS: &base}
// after
cfg := connectionConfig{} // leave nil to use the default backoff

Defensive patterns

Strategy: validation

Validate before calling

if cfg.BaseSleepTimeMS != nil && *cfg.BaseSleepTimeMS < 0 {
    return errors.New("base_sleep_time_ms must be non-negative")
}

Try / catch

_, err := openClient(cfg)
if err != nil && strings.Contains(err.Error(), "base_sleep_time_ms") {
    return fmt.Errorf("fix retry backoff config: %w", err)
}

Prevention

Clamp computed backoff values with max(0, v) before assigning
Leave BaseSleepTimeMS nil to use driver defaults unless tuning is deliberate
Never use negative numbers as sentinels for 'auto' in this config
Unit-test config parsing for sign and unit (ms vs s) mistakes

When it happens

Trigger: connectionConfig.BaseSleepTimeMS is a non-nil pointer to a negative integer when connect or testConnection calls openClient.

Common situations: Computed backoff value accidentally negative (e.g. subtraction underflow); YAML/JSON numeric parse producing a negative; confusing ms with seconds and entering a sentinel negative for 'auto'.

Understand the failure class

Background: "Invalid configuration value" and "Unsupported/Unknown setting value" errors: why libraries reject your config strings, numbers, and types — this error's family across 30 libraries.

Related errors

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/208f59ad8eb13cf8. Report an issue: GitHub.