prometheus/node_exporter · error

could not parse expected integer value for

Error message

could not parse expected integer value for %q

What it means

parsePoolObjsetFile parses an objset kstat file in 'key: type: value' format. When the type is 'uint64' it parses parts[2] with strconv.ParseUint; on failure it returns this error naming the kstat.zfs.misc.objset.<key>. Unlike the pool parser, it does not wrap the underlying parse error, so the cause must be inferred from the named key.

Solutions

1. Check the named objset key's value in the procfs/fixture file and make it a valid unsigned integer
2. Add %w wrapping of the ParseUint error to ease diagnosis
3. Ensure lines follow 'name: uint64: <int>' format exactly
4. Refresh fixtures from a live system

Example fix

// before
return fmt.Errorf("could not parse expected integer value for %q", key)
// after
return fmt.Errorf("could not parse expected integer value for %q: %w", key, err)

parts := strings.Split(strings.TrimSpace(lineStr), " ")
if len(parts) == 3 && parts[1] == "uint64" {
    if _, err := strconv.ParseUint(parts[2], 10, 64); err != nil {
        // skip line; not a parseable uint64 value
    }
}

if err := c.parsePoolObjsetFile(f, pool, ds, handler); err != nil {
    if strings.Contains(err.Error(), "did not parse a single") || strings.Contains(err.Error(), "could not parse") {
        c.logger.Warn("objset parse issue", "err", err)
        return nil
    }
    return err
}

When it happens

Trigger: An objset line whose declared type is uint64 has a third field that is empty or non-numeric (e.g. '-'), so strconv.ParseUint fails during updatePoolStats.

Common situations: Fixture files with placeholder values; ZFS versions emitting non-numeric placeholders for some objset stats; line-format drift where the value column moved.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• could not parse expected integer value for
• did not parse a single
• ZFS / ZFS statistics are not available
• failed to parse /proc/net/dev
• interrupts empty

AI-assisted analysis of prometheus/node_exporter@17ddd77c59 (2026-09-07). Data as JSON: /api/errors/aa40a3039839b455. Report an issue: GitHub.

Appendix: source

Thrown at collector/zfs_linux.go:326

			continue
		}

		if !parseLine || len(parts) < 3 {
			continue
		}
		if parts[0] == "dataset_name" {
			zpoolPathElements := strings.Split(zpoolPath, "/")
			pathLen := len(zpoolPathElements)
			zpoolName = zpoolPathElements[pathLen-2]
			datasetName = line[strings.Index(line, parts[2]):]
			continue
		}

		if parts[1] == kstatDataUint64 {
			key := fmt.Sprintf("kstat.zfs.misc.objset.%s", parts[0])
			value, err := strconv.ParseUint(parts[2], 10, 64)
			if err != nil {
				return fmt.Errorf("could not parse expected integer value for %q", key)
			}
			handler(zpoolName, datasetName, zfsSysctl(key), value)
		}
	}
	if !parseLine {
		return fmt.Errorf("did not parse a single %s %s metric", zpoolName, datasetName)
	}

	return scanner.Err()
}

func (c *zfsCollector) parsePoolStateFile(reader io.Reader, zpoolPath string, handler func(string, string, uint64)) error {
	scanner := bufio.NewScanner(reader)
	scanner.Scan()

	actualStateName, err := scanner.Text(), scanner.Err()
	if err != nil {
		return err

View on GitHub (pinned to 17ddd77c59)