Example #1
0
// processLoop processes the entries in the queue until the provided
// stopper signals exit.
//
// TODO(spencer): current load should factor into replica processing timer.
func (bq *baseQueue) processLoop(clock *hlc.Clock, stopper *stop.Stopper) {
	stopper.RunWorker(func() {
		defer func() {
			bq.mu.Lock()
			bq.mu.stopped = true
			bq.mu.Unlock()
			log.FinishEventLog(bq.ctx)
		}()

		// nextTime is initially nil; we don't start any timers until the queue
		// becomes non-empty.
		var nextTime <-chan time.Time

		immediately := make(chan time.Time)
		close(immediately)

		for {
			select {
			// Exit on stopper.
			case <-stopper.ShouldStop():
				return

			// Incoming signal sets the next time to process if there were previously
			// no replicas in the queue.
			case <-bq.incoming:
				if nextTime == nil {
					// When a replica is added, wake up immediately. This is mainly
					// to facilitate testing without unnecessary sleeps.
					nextTime = immediately

					// In case we're in a test, still block on the impl.
					bq.impl.timer()
				}
			// Process replicas as the timer expires.
			case <-nextTime:
				repl := bq.pop()
				if repl != nil {
					if stopper.RunTask(func() {
						if err := bq.processReplica(repl, clock); err != nil {
							// Maybe add failing replica to purgatory if the queue supports it.
							bq.maybeAddToPurgatory(repl, err, clock, stopper)
						}
					}) != nil {
						return
					}
				}
				if bq.Length() == 0 {
					nextTime = nil
				} else {
					nextTime = time.After(bq.impl.timer())
				}
			}
		}
	})
}
Example #2
0
// New creates an instance of a gossip node.
func New(
	ctx context.Context,
	rpcContext *rpc.Context,
	grpcServer *grpc.Server,
	resolvers []resolver.Resolver,
	stopper *stop.Stopper,
	registry *metric.Registry,
) *Gossip {
	ctx = log.WithEventLog(ctx, "gossip", "gossip")
	g := &Gossip{
		ctx:               ctx,
		Connected:         make(chan struct{}),
		rpcContext:        rpcContext,
		server:            newServer(ctx, stopper, registry),
		outgoing:          makeNodeSet(minPeers, metric.NewGauge(MetaConnectionsOutgoingGauge)),
		bootstrapping:     map[string]struct{}{},
		disconnected:      make(chan *client, 10),
		stalledCh:         make(chan struct{}, 1),
		stallInterval:     defaultStallInterval,
		bootstrapInterval: defaultBootstrapInterval,
		cullInterval:      defaultCullInterval,
		nodeDescs:         map[roachpb.NodeID]*roachpb.NodeDescriptor{},
		resolverAddrs:     map[util.UnresolvedAddr]resolver.Resolver{},
		bootstrapAddrs:    map[util.UnresolvedAddr]struct{}{},
	}
	stopper.AddCloser(stop.CloserFn(func() {
		log.FinishEventLog(ctx)
	}))

	registry.AddMetric(g.outgoing.gauge)
	g.clientsMu.breakers = map[string]*circuit.Breaker{}
	log.Infof(g.ctx, "initial resolvers: %s", resolvers)
	g.SetResolvers(resolvers)

	g.mu.Lock()
	// Add ourselves as a SystemConfig watcher.
	g.mu.is.registerCallback(KeySystemConfig, g.updateSystemConfig)
	// Add ourselves as a node descriptor watcher.
	g.mu.is.registerCallback(MakePrefixPattern(KeyNodeIDPrefix), g.updateNodeAddress)
	g.mu.Unlock()

	RegisterGossipServer(grpcServer, g.server)
	return g
}