thanos-io/thanos · error

get tenant appendable

Error message

get tenant appendable

What it means

Error from Thanos receive Writer.Write: the multi-TSDB could not return an Appendable for the given tenant (multiTSDB.TenantAppendable failed). This usually means the tenant is unknown/not allowed, the tenant ID is invalid, or the per-tenant TSDB cannot be opened/created.

Solutions

1. Check the wrapped cause to see if it is tenant validation or TSDB open failure.
2. Verify the tenant ID against the receive --receive.tenant-header / allowed tenants config and fix the sender's header value.
3. Ensure the TSDB data directory is writable and has disk space.
4. Confirm the multiTSDB was initialized with the tenant (hashrings/replication config) before writes.

Example fix

// before: arbitrary tenant from header
tenant := r.Header.Get("X-Scope-OrgID") // "foo bar" (invalid)
// after: validate against allowlist
if !allowedTenants[tenant] { http.Error(w, "unknown tenant", 400); return }

if tenant == "" || !validTenantRegex.MatchString(tenant) {
    return errors.New("invalid or missing tenant ID")
}
if !allowedTenants[tenant] { return fmt.Errorf("tenant %q not allowed", tenant) }

if err := writer.Write(ctx, tenant, series); err != nil {
    if strings.Contains(err.Error(), "get tenant appendable") {
        // reject request with 400/404, do not retry against same tenant
    }
}

When it happens

Trigger: Writer.Write called with a tenantID for which TenantAppendable returns an error - e.g. tenant not matching allowed tenants configuration, illegal tenant label characters, or failure opening/creating the tenant's TSDB directory.

Common situations: Remote-write senders using a tenant header (e.g. thanos tenant: X-Scope-OrgID) that isn't in the receiver's allowed list; typo'd tenant IDs; disk/permission problems preventing per-tenant TSDB creation.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• get appender
• commit samples
• add series
• start remote write agent db
• open TSDB

AI-assisted analysis of thanos-io/thanos@35b8b99117 (2026-09-07). Data as JSON: /api/errors/05dc17c1d16dfee9. Report an issue: GitHub.

Appendix: source

Thrown at pkg/receive/writer.go:79

}

func NewWriter(logger log.Logger, multiTSDB TenantStorage, opts *WriterOptions) *Writer {
	if opts == nil {
		opts = &WriterOptions{}
	}
	return &Writer{
		logger:    logger,
		multiTSDB: multiTSDB,
		opts:      opts,
	}
}

func (r *Writer) Write(ctx context.Context, tenantID string, wreq []prompb.TimeSeries) error {
	tLogger := log.With(r.logger, "tenant", tenantID)

	s, err := r.multiTSDB.TenantAppendable(tenantID)
	if err != nil {
		return errors.Wrap(err, "get tenant appendable")
	}

	app, err := s.Appender(ctx)
	if err == tsdb.ErrNotReady {
		return err
	}
	if err != nil {
		return errors.Wrap(err, "get appender")
	}
	getRef := app.(storage.GetRef)
	var (
		ref          storage.SeriesRef
		errorTracker writeErrorTracker
	)
	app = &ReceiveAppender{
		tLogger:        tLogger,
		tooFarInFuture: r.opts.TooFarInFutureTimeWindow,
		Appender:       app,

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