What causes "parsing TTL: %w" in grafana/k6?

Fix options.dns.ttl to a single valid duration or '0'/'inf'

parsing TTL: %w

Error message

parsing TTL: %w

What it means

Intermediate wrap in newResolver: the k6types-based parseTTL helper rejected the dns.ttl string from options. It appears inside the chain 'newResolver(...): parsing TTL: invalid DNS TTL: <value>' whenever a new browser page/context is created, pointing squarely at the test's DNS configuration.

Source

Thrown at internal/js/modules/k6/browser/common/network_manager.go:169

		"connectionaborted":    network.ErrorReasonConnectionAborted,
		"connectionclosed":     network.ErrorReasonConnectionClosed,
		"connectionfailed":     network.ErrorReasonConnectionFailed,
		"connectionrefused":    network.ErrorReasonConnectionRefused,
		"connectionreset":      network.ErrorReasonConnectionReset,
		"internetdisconnected": network.ErrorReasonInternetDisconnected,
		"namenotresolved":      network.ErrorReasonNameNotResolved,
		"timedout":             network.ErrorReasonTimedOut,
		"failed":               network.ErrorReasonFailed,
	}
}

// Returns a new Resolver.
// Copied with minor changes from
// https://github.com/grafana/k6/blob/fb70bc6f3d3f22a40e65f32deea3cea1b6d70a76/js/runner.go#L459
func newResolver(conf k6types.DNSConfig) (k6netext.Resolver, error) {
	ttl, err := parseTTL(conf.TTL.String)
	if err != nil {
		return nil, fmt.Errorf("parsing TTL: %w", err)
	}

	dnsSel := conf.Select
	if !dnsSel.Valid {
		dnsSel = k6types.DefaultDNSConfig().Select
	}
	dnsPol := conf.Policy
	if !dnsPol.Valid {
		dnsPol = k6types.DefaultDNSConfig().Policy
	}
	return k6netext.NewResolver(
		net.LookupIP, ttl, dnsSel.DNSSelect, dnsPol.DNSPolicy), nil
}

// Parse a string representation of TTL to time.Duration.
// Copied from https://github.com/grafana/k6/blob/fb70bc6f3d3f22a40e65f32deea3cea1b6d70a76/js/runner.go#L479
func parseTTL(ttlS string) (time.Duration, error) {
	ttl := time.Duration(0)

View on GitHub (pinned to 93accf6570)

Solutions

Fix options.dns.ttl to a single valid duration or '0'/'inf'
Check overridden config sources: --config file, K6_DNS_TTL env var, cloud-originated options
Rule out list syntax ('1m,5m') which is unsupported here
Re-run with a minimal script to confirm the dns block is the culprit

Example fix

# before
K6_DNS_TTL='1m,5m' k6 run script.js

# after
K6_DNS_TTL='1m' k6 run script.js

Defensive patterns

Strategy: validation

Validate before calling

const m = /newResolver\(.*parsing TTL: invalid DNS TTL: (.+)/.exec(err.message);
if (m) throw new Error(`fix options.dns.ttl: '${m[1]}' is not 0|inf|<duration>`);

Type guard

function isValidTtl(v) {
  return v === '0' || v === 'inf' || /^\d+(\.\d+)?(ms|s|m|h)$/.test(v);
}

Prevention

Audit --config files and K6_DNS_TTL in CI for list syntax
Unit-check option generation when templating scripts
Note empty ttl is valid (default applied); lists are not

When it happens

Trigger: Browser page creation with options.dns.ttl set to a string that is not '0', 'inf', empty, or parseable by ParseExtendedDuration (typos, unknown units, negative values, comma-separated lists).

Common situations: Copy-pasted options from k6 HTTP tests using TTL lists; CI injecting options via --config or environment (K6_DNS_TTL) with a bad value; unit mismatch after editing '600s' to '10m' style values by hand.

Related errors

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/56ecfb38ea415d36. Report an issue: GitHub.