jaegertracing/jaeger · error

failed to check if index exists: %w

Error message

failed to check if index exists: %w

What it means

Returned by IndicesClient.IndexExists when the HEAD request against an index fails with anything other than a 404 ResponseError. 404 maps to (false, nil) — index absent. Any other failure becomes this wrapped error, meaning the existence probe itself could not be completed.

Source

Thrown at internal/storage/elasticsearch/esclient/index_client.go:243

		return false, fmt.Errorf("failed to check if alias exists: %w", err)
	}
	return true, nil
}

// IndexExists check whether an index exists or not
func (i *IndicesClient) IndexExists(ctx context.Context, index string) (bool, error) {
	_, err := i.request(ctx, elasticRequest{
		endpoint: index,
		method:   http.MethodHead,
	})
	if err != nil {
		var responseError ResponseError
		if errors.As(err, &responseError) {
			if responseError.StatusCode == http.StatusNotFound {
				return false, nil
			}
		}
		return false, fmt.Errorf("failed to check if index exists: %w", err)
	}
	return true, nil
}

func (*IndicesClient) aliasesString(aliases []Alias) string {
	var builder strings.Builder
	for _, alias := range aliases {
		fmt.Fprintf(&builder, "[index: %s, alias: %s],", alias.Index, alias.Name)
	}
	concatAliases := builder.String()
	return strings.Trim(concatAliases, ",")
}

func (i *IndicesClient) aliasAction(ctx context.Context, action string, aliases []Alias) error {
	actions := []map[string]any{}

	for _, alias := range aliases {
		options := map[string]any{

View on GitHub (pinned to 806f444784)

Solutions

1. Verify connectivity and credentials (curl -I the index URL); 401/403 point at auth config
2. Treat as 'probe failed' — do not assume the index is missing; retry before creating it
3. Check cluster health and load-balancer behavior for 5xx responses
4. Unwrap the %w chain to identify the transport cause

Example fix

// before
ok, err := client.IndexExists(ctx, "jaeger-span-000001")
if err != nil { return err }
// after
ok, err := client.IndexExists(ctx, "jaeger-span-000001")
if err != nil {
    return fmt.Errorf("cannot determine index existence, not bootstrapping: %w", err)
}

// pre-flight auth + connectivity
resp, err := http.Get(esURL + "/_cluster/health")
if err != nil || resp.StatusCode != 200 {
    return fmt.Errorf("ES not reachable")
}

var respErr esclient.ResponseError
isAuthProblem := func(err error) bool {
    var re esclient.ResponseError
    return errors.As(err, &re) && (re.StatusCode == 401 || re.StatusCode == 403)
}

ok, err := client.IndexExists(ctx, index)
if err != nil {
    var respErr esclient.ResponseError
    if errors.As(err, &respErr) {
        return fmt.Errorf("index probe rejected, status=%d", respErr.StatusCode)
    }
    return retryable(err) // never bootstrap indices on a failed probe
}

When it happens

Trigger: HEAD /<index> fails without a 404 ResponseError: network outage, timeout, canceled context, or non-404 HTTP errors (401 unauthorized, 503 unavailable) not wrapped as ResponseError.

Common situations: Bad ES credentials during first-time setup; ES down while Jaeger decides whether to bootstrap indices; proxy returning HTML error pages that defeat ResponseError parsing.

Related errors

• failed to delete indices: %w
• failed to resolve backend version: %w
• failed to create index: %w
• failed to create aliases: %w
• failed to delete aliases: %w

AI-assisted analysis of jaegertracing/jaeger@806f444784 (2026-09-01). Data as JSON: /api/errors/83ac226da97948fd. Report an issue: GitHub.