cayleygraph/cayley · error

could not retrieve maxIdleConnections from options: %v

Error message

could not retrieve maxIdleConnections from options: %v

What it means

connect reads the "maxidleconnections" integer option via graph.Options.IntKey (default -1). A non-integer value makes IntKey fail and connect wraps it as "could not retrieve maxIdleConnections from options". Reached via Init or New.

Source

Thrown at graph/sql/quadstore.go:128

	sizes   *lru.Cache
	noSizes bool

	mu    sync.RWMutex
	nodes int64
	quads int64
}

func connect(addr string, flavor string, opts graph.Options) (*sql.DB, error) {
	maxOpenConnections, err := opts.IntKey("maxopenconnections", -1)

	if err != nil {
		return nil, fmt.Errorf("could not retrieve maxopenconnections from options: %v", err)
	}

	maxIdleConnections, err := opts.IntKey("maxidleconnections", -1)

	if err != nil {
		return nil, fmt.Errorf("could not retrieve maxIdleConnections from options: %v", err)
	}

	connMaxLifetime, err := opts.StringKey("connmaxlifetime", "")

	if err != nil {
		return nil, fmt.Errorf("could not retrieve connmaxlifetime from options: %v", err)
	}

	var connDuration time.Duration
	if connMaxLifetime != "" {
		connDuration, err = time.ParseDuration(connMaxLifetime)

		if err != nil {
			return nil, fmt.Errorf("couldn't parse connmaxlifetime string: %v", err)
		}
	}

	// TODO(barakmich): Parse options for more friendly addr

View on GitHub (pinned to 81dcd7d73e)

Solutions

1. Provide "maxidleconnections" as an integer, or omit the key to use the default.
2. Read the wrapped underlying error to confirm the parse failure.
3. Sanitize config loading so numeric fields aren't delivered as strings.

Example fix

// before
{"maxidleconnections": "five"}
// after
{"maxidleconnections": 5}

if v, ok := opts["maxidleconnections"]; ok {
    if _, err := strconv.Atoi(fmt.Sprint(v)); err != nil {
        return fmt.Errorf("maxidleconnections must be an integer, got %v", v)
    }
}

qs, err := quadstore.New(addr, opts)
if err != nil {
    if strings.Contains(err.Error(), "maxIdleConnections") {
        // correct the option and retry
    }
}

When it happens

Trigger: New/Init call where opts contains "maxidleconnections" with a non-integer value (string, bool, nested value).

Common situations: Misquoted or mistyped values in a database config file; environment-variable-driven configs that pass raw strings; typo producing a value of the wrong type in the Options map.

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

• could not retrieve maxopenconnections from options: %v
• could not retrieve connmaxlifetime from options: %v
• couldn't parse connmaxlifetime string: %v
• Invalid %s parameter type from config: %T
• could not open config file %q: %v

AI-assisted analysis of cayleygraph/cayley@81dcd7d73e (2026-09-06). Data as JSON: /api/errors/62aea67a1a105ba3. Report an issue: GitHub.