Method stopping

ring/lifecycler.go:622–676

Shutdown the lifecycle. It will: - send chunks to another ingester, if it can. - otherwise, flush chunks to the chunk store. - remove config from Consul.

(runningError error)

// - otherwise, flush chunks to the chunk store.
// - remove config from Consul.
func (i *Lifecycler) stopping(runningError error) error {
	if runningError != nil {
		// previously lifecycler just called os.Exit (from loop method)...
		// now it stops more gracefully, but also without doing any cleanup
		level.Error(i.logger).Log("msg", "lifecycler loop() exited with error", "err", runningError)
		return runningError
	}

	heartbeatTickerStop, heartbeatTickerChan := newDisableableTicker(i.cfg.HeartbeatPeriod)
	defer heartbeatTickerStop()

	// Mark ourselved as Leaving so no more samples are send to us.
	err := i.changeState(context.Background(), LEAVING)
	if err != nil {
		level.Error(i.logger).Log("msg", "failed to set state to LEAVING", "ring", i.RingName, "err", err)
	}

	// Do the transferring / flushing on a background goroutine so we can continue
	// to heartbeat to consul.
	done := make(chan struct{})
	go func() {
		i.processShutdown(context.Background())
		close(done)
	}()

heartbeatLoop:
	for {
		select {
		case <-heartbeatTickerChan:
			i.lifecyclerMetrics.consulHeartbeats.Inc()
			if err := i.updateConsul(context.Background()); err != nil {
				level.Error(i.logger).Log("msg", "failed to write to the KV store, sleeping", "ring", i.RingName, "err", err)
			}

		case <-done:
			break heartbeatLoop
		}
	}

	if i.ShouldUnregisterOnShutdown() {
		if err := i.unregister(context.Background()); err != nil {
			return errors.Wrapf(err, "failed to unregister from the KV store, ring: %s", i.RingName)
		}
		level.Info(i.logger).Log("msg", "instance removed from the KV store", "ring", i.RingName)
	}

	if i.cfg.TokensFilePath != "" && i.ClearTokensOnShutdown() {
		if err := os.Remove(i.cfg.TokensFilePath); err != nil {
			return errors.Wrapf(err, "failed to delete tokens file %s", i.cfg.TokensFilePath)
		}
		level.Info(i.logger).Log("msg", "removed tokens file from disk", "path", i.cfg.TokensFilePath)
	}

	return nil
}

// initRing is the first thing we do when we start. It:
// - adds an ingester entry to the ring