Method waitBeforeJoining

ring/lifecycler.go:865–909

(ctx context.Context)

}

func (i *Lifecycler) waitBeforeJoining(ctx context.Context) error {
	if !i.tokenGenerator.CanJoinEnabled() {
		return nil
	}

	level.Info(i.logger).Log("msg", "waiting to be able to join the ring", "ring", i.RingName, "id", i.cfg.ID, "timeout", i.canJoinTimeout)

	ctxWithTimeout, cancel := context.WithTimeout(ctx, i.canJoinTimeout)
	defer cancel()
	retries := backoff.New(ctxWithTimeout, backoff.Config{
		MinBackoff: 1 * time.Second,
		MaxBackoff: 1 * time.Second,
		MaxRetries: 0,
	})

	var lastError error
	for ; retries.Ongoing(); retries.Wait() {
		var desc interface{}
		desc, lastError = i.KVStore.Get(ctxWithTimeout, i.RingKey)
		if lastError != nil {
			lastError = errors.Wrap(lastError, "error getting the ring from the KV store")
			continue
		}

		ringDesc, ok := desc.(*Desc)
		if !ok || ringDesc == nil {
			lastError = fmt.Errorf("no ring returned from the KV store")
			continue
		}
		lastError = i.tokenGenerator.CanJoin(ringDesc.GetIngesters())
		if lastError == nil {
			level.Info(i.logger).Log("msg", "it is now possible to join the ring", "ring", i.RingName, "id", i.cfg.ID, "retries", retries.NumRetries())
			return nil
		}
	}

	if lastError == nil {
		lastError = retries.Err()
	}
	level.Warn(i.logger).Log("msg", "there was a problem while checking whether this instance could join the ring - will continue anyway", "ring", i.RingName, "id", i.cfg.ID, "err", lastError)

	// Return error only in case the parent context has been cancelled.
	// In all other cases, we just want to swallow the error and move on.
	return ctx.Err()
}

// autoJoin selects random tokens & moves state to targetState
func (i *Lifecycler) autoJoin(ctx context.Context, targetState InstanceState) error {