Method registerInstance

ring/basic_lifecycler.go:313–371

registerInstance registers the instance in the ring. The initial state and set of tokens depends on the OnRingInstanceRegister() delegate function.

(ctx context.Context)

// registerInstance registers the instance in the ring. The initial state and set of tokens
// depends on the OnRingInstanceRegister() delegate function.
func (l *BasicLifecycler) registerInstance(ctx context.Context) error {
	var instanceDesc InstanceDesc

	err := l.store.CAS(ctx, l.ringKey, func(in interface{}) (out interface{}, retry bool, err error) {
		ringDesc := GetOrCreateRingDesc(in)

		var exists bool
		instanceDesc, exists = ringDesc.Ingesters[l.cfg.ID]
		if exists {
			level.Info(l.logger).Log("msg", "instance found in the ring", "instance", l.cfg.ID, "ring", l.ringName, "state", instanceDesc.GetState(), "tokens", len(instanceDesc.GetTokens()), "registered_at", instanceDesc.GetRegisteredAt().String(), "last_heartbeat_at", instanceDesc.GetLastHeartbeatAt().String())
		} else {
			level.Info(l.logger).Log("msg", "instance not found in the ring", "instance", l.cfg.ID, "ring", l.ringName)
		}

		// We call the delegate to get the desired state right after the initialization.
		state, tokens := l.delegate.OnRingInstanceRegister(l, *ringDesc, exists, l.cfg.ID, instanceDesc)

		// Ensure tokens are sorted.
		sort.Sort(tokens)

		// If the instance didn't already exist, then we can safely set the registered timestamp to "now",
		// otherwise we have to honor the previous value (even if it was zero, because means it was unknown
		// but it's definitely not "now").
		var registeredAt time.Time
		if exists {
			registeredAt = instanceDesc.GetRegisteredAt()
		} else {
			registeredAt = time.Now()
		}

		readOnly, readOnlyUpdatedTimestamp := instanceDesc.GetReadOnlyState()
		if readOnlyUpdatedTimestamp.IsZero() {
			// Store the zero timestamp as 0 in the ring, not as -62135596800.
			readOnlyUpdatedTimestamp = time.Unix(0, 0)
		}
		// Always overwrite the instance in the ring (even if already exists) because some properties
		// may have changed (stated, tokens, zone, address) and even if they didn't the heartbeat at
		// least did.
		instanceDesc = ringDesc.AddIngester(l.cfg.ID, l.cfg.Addr, l.cfg.Zone, tokens, state, registeredAt, readOnly, readOnlyUpdatedTimestamp, l.cfg.Versions)
		return ringDesc, true, nil
	})

	if err != nil {
		return err
	}

	l.currState.Lock()
	l.currInstanceDesc = &instanceDesc
	l.currState.Unlock()

	// Initialize the read-only metric to reflect the current state after registration.
	if instanceDesc.ReadOnly {
		l.metrics.readOnly.Set(1)
	} else {
		l.metrics.readOnly.Set(0)
	}

	return nil