thanos-io/thanos · warning

ErrParseKeyInt

ErrParseKeyInt

Error message

failed to parse integer in key

What it means

For subrange cache keys ("subrange:name:start:end"), ParseBucketCacheKey parses the 3rd and 4th fields with strconv.ParseInt. If either start or end is not a valid base-10 64-bit integer, ErrParseKeyInt is returned, meaning the key is structurally right but numerically malformed.

Solutions

1. Validate that the start/end segments parse as int64 before calling ParseBucketCacheKey and skip invalid entries.
2. Clear the cache backend of corrupted or truncated keys.
3. Check whether the cache backend truncates or mangles long keys and raise its limits.
4. Fix any custom producer emitting non-integer offsets.

Example fix

// before
ck, err := cachekey.ParseBucketCacheKey(key)
// after
parts := strings.Split(key, ":")
if len(parts) >= 4 {
    if _, e1 := strconv.ParseInt(parts[2], 10, 64); e1 != nil {
        return nil, nil // skip bad subrange key
    }
}
ck, err := cachekey.ParseBucketCacheKey(key)

parts := strings.Split(key, ":")
if len(parts) >= 4 {
    if _, err := strconv.ParseInt(parts[2], 10, 64); err != nil {
        return nil, fmt.Errorf("bad start %q", parts[2])
    }
    if _, err := strconv.ParseInt(parts[3], 10, 64); err != nil {
        return nil, fmt.Errorf("bad end %q", parts[3])
    }
}

ck, err := cachekey.ParseBucketCacheKey(key)
if errors.Is(err, cachekey.ErrParseKeyInt) {
    logger.Debug("corrupted subrange key, skipping", "key", key)
    continue
}

When it happens

Trigger: ParseBucketCacheKey called with a subrange key whose start or end field is non-numeric or out of int64 range, e.g. "subrange:obj:abc:def" or "subrange:obj:99999999999999999999:200".

Common situations: Corrupted cache entries in memcached/redis; hand-written keys in tooling or tests; truncation of keys by a cache backend with key length limits.

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.

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• ErrInvalidBucketCacheKeyFormat
• ErrInvalidBucketCacheKeyVerb
• errObjNotFound
• failed to get object attributes
• fetching range [ , ]: caching key for offset not found

AI-assisted analysis of thanos-io/thanos@35b8b99117 (2026-09-07). Data as JSON: /api/errors/a4add6984be4a95a. Report an issue: GitHub.

Appendix: source

Thrown at pkg/store/cache/cachekey/cachekey.go:16

// Copyright (c) The Thanos Authors.
// Licensed under the Apache License 2.0.

package cachekey

import (
	"strconv"
	"strings"

	"github.com/pkg/errors"
)

var (
	ErrInvalidBucketCacheKeyFormat = errors.New("key has invalid format")
	ErrInvalidBucketCacheKeyVerb   = errors.New("key has invalid verb")
	ErrParseKeyInt                 = errors.New("failed to parse integer in key")
)

// VerbType is the type of operation whose result has been stored in the caching bucket's cache.
type VerbType string

const (
	ExistsVerb        VerbType = "exists"
	ContentVerb       VerbType = "content"
	IterVerb          VerbType = "iter"
	IterRecursiveVerb VerbType = "iter-recursive"
	AttributesVerb    VerbType = "attrs"
	SubrangeVerb      VerbType = "subrange"
)

type BucketCacheKey struct {
	Verb                    VerbType
	Name                    string
	Start                   int64

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