Example #1
0
// TestGossipStorageCleanup verifies that bad resolvers are purged
// from the bootstrap info after gossip has successfully connected.
func TestGossipStorageCleanup(t *testing.T) {
	defer leaktest.AfterTest(t)()
	stopper := stop.NewStopper()
	defer stopper.Stop()

	const numNodes = 3
	network := simulation.NewNetwork(stopper, numNodes, false)

	const notReachableAddr = "localhost:0"
	const invalidAddr = "10.0.0.1000:3333333"
	// Set storage for each of the nodes.
	addresses := make(unresolvedAddrSlice, len(network.Nodes))
	stores := make([]testStorage, len(network.Nodes))
	for i, n := range network.Nodes {
		addresses[i] = util.MakeUnresolvedAddr(n.Addr().Network(), n.Addr().String())
		// Pre-add an invalid address to each gossip storage.
		if err := stores[i].WriteBootstrapInfo(&gossip.BootstrapInfo{
			Addresses: []util.UnresolvedAddr{
				util.MakeUnresolvedAddr("tcp", network.Nodes[(i+1)%numNodes].Addr().String()), // node i+1 address
				util.MakeUnresolvedAddr("tcp", notReachableAddr),                              // unreachable address
				util.MakeUnresolvedAddr("tcp", invalidAddr),                                   // invalid address
			},
		}); err != nil {
			t.Fatal(err)
		}
		if err := n.Gossip.SetStorage(&stores[i]); err != nil {
			t.Fatal(err)
		}
		n.Gossip.SetStallInterval(1 * time.Millisecond)
		n.Gossip.SetBootstrapInterval(1 * time.Millisecond)
	}

	// Wait for the gossip network to connect.
	network.RunUntilFullyConnected()

	// Let the gossip network continue running in the background without the
	// simulation cycler preventing it from operating.
	for _, node := range network.Nodes {
		node.Gossip.EnableSimulationCycler(false)
	}

	// Wait long enough for storage to get the expected number of
	// addresses and no pending cleanups.
	testutils.SucceedsSoon(t, func() error {
		for i := range stores {
			p := &stores[i]
			if expected, actual := len(network.Nodes)-1 /* -1 is ourself */, p.Len(); expected != actual {
				return errors.Errorf("expected %v, got %v (info: %#v)", expected, actual, p.Info().Addresses)
			}
			for _, addr := range p.Info().Addresses {
				if addr.String() == invalidAddr {
					return errors.Errorf("node %d still needs bootstrap cleanup", i)
				}
			}
		}
		return nil
	})
}
Example #2
0
func main() {
	// Seed the random number generator for non-determinism across
	// multiple runs.
	randutil.SeedForTests()

	if f := flag.Lookup("alsologtostderr"); f != nil {
		fmt.Println("Starting simulation. Add -alsologtostderr to see progress.")
	}
	flag.Parse()

	dirName, err := ioutil.TempDir("", "gossip-simulation-")
	if err != nil {
		log.Fatalf(context.TODO(), "could not create temporary directory for gossip simulation output: %s", err)
	}

	// Simulation callbacks to run the simulation for cycleCount
	// cycles. At each cycle % outputEvery, a dot file showing the
	// state of the network graph is output.
	nodeCount := 3
	switch *size {
	case "tiny":
		// Use default parameters.
	case "small":
		nodeCount = 10
	case "medium":
		nodeCount = 25
	case "large":
		nodeCount = 50
	case "huge":
		nodeCount = 100
	case "ginormous":
		nodeCount = 250
	default:
		log.Fatalf(context.TODO(), "unknown simulation size: %s", *size)
	}

	edgeSet := make(map[string]edge)

	stopper := stop.NewStopper()
	defer stopper.Stop()

	n := simulation.NewNetwork(stopper, nodeCount, true)
	n.SimulateNetwork(
		func(cycle int, network *simulation.Network) bool {
			// Output dot graph.
			dotFN := fmt.Sprintf("%s/sim-cycle-%03d.dot", dirName, cycle)
			_, quiescent := outputDotFile(dotFN, cycle, network, edgeSet)
			// Run until network has quiesced.
			return !quiescent
		},
	)

	// Output instructions for viewing graphs.
	fmt.Printf("To view simulation graph output run (you must install graphviz):\n\nfor f in %s/*.dot ; do circo $f -Tpng -o $f.png ; echo $f.png ; done\n", dirName)
}
Example #3
0
// TestConvergence verifies a 10 node gossip network converges within
// a fixed number of simulation cycles. It's really difficult to
// determine the right number for cycles because different things can
// happen during a single cycle, depending on how much CPU time is
// available. Eliminating this variability by getting more
// synchronization primitives in place for the simulation is possible,
// though two attempts so far have introduced more complexity into the
// actual production gossip code than seems worthwhile for a unittest.
func TestConvergence(t *testing.T) {
	defer leaktest.AfterTest(t)()
	stopper := stop.NewStopper()
	defer stopper.Stop()

	network := simulation.NewNetwork(stopper, 10, true)

	const maxCycles = 100
	if connectedCycle := network.RunUntilFullyConnected(); connectedCycle > maxCycles {
		log.Warningf(context.TODO(), "expected a fully-connected network within %d cycles; took %d",
			maxCycles, connectedCycle)
	}
}
Example #4
0
// TestGossipStorage verifies that a gossip node can join the cluster
// using the bootstrap hosts in a gossip.Storage object.
func TestGossipStorage(t *testing.T) {
	defer leaktest.AfterTest(t)()
	stopper := stop.NewStopper()
	defer stopper.Stop()

	network := simulation.NewNetwork(stopper, 3, true)

	// Set storage for each of the nodes.
	addresses := make(unresolvedAddrSlice, len(network.Nodes))
	stores := make([]testStorage, len(network.Nodes))
	for i, n := range network.Nodes {
		addresses[i] = util.MakeUnresolvedAddr(n.Addr().Network(), n.Addr().String())
		if err := n.Gossip.SetStorage(&stores[i]); err != nil {
			t.Fatal(err)
		}
	}

	// Wait for the gossip network to connect.
	network.RunUntilFullyConnected()

	// Wait long enough for storage to get the expected number of addresses.
	testutils.SucceedsSoon(t, func() error {
		for i := range stores {
			p := &stores[i]

			if expected, actual := len(network.Nodes)-1 /* -1 is ourself */, p.Len(); expected != actual {
				return errors.Errorf("expected %v, got %v (info: %#v)", expected, actual, p.Info().Addresses)
			}
		}
		return nil
	})

	for i := range stores {
		p := &stores[i]

		if !p.isRead() {
			t.Errorf("%d: expected read from storage", i)
		}
		if !p.isWrite() {
			t.Errorf("%d: expected write from storage", i)
		}

		p.Lock()
		gotAddresses := unresolvedAddrSlice(p.info.Addresses)
		sort.Sort(gotAddresses)
		var expectedAddresses unresolvedAddrSlice
		for j, addr := range addresses {
			if i != j { // skip node's own address
				expectedAddresses = append(expectedAddresses, addr)
			}
		}
		sort.Sort(expectedAddresses)

		// Verify all gossip addresses are written to each persistent store.
		if !reflect.DeepEqual(gotAddresses, expectedAddresses) {
			t.Errorf("%d: expected addresses: %s, got: %s", i, expectedAddresses, gotAddresses)
		}
		p.Unlock()
	}

	// Create an unaffiliated gossip node with only itself as a resolver,
	// leaving it no way to reach the gossip network.
	node, err := network.CreateNode()
	if err != nil {
		t.Fatal(err)
	}
	node.Gossip.SetBootstrapInterval(1 * time.Millisecond)

	r, err := resolver.NewResolverFromAddress(node.Addr())
	if err != nil {
		t.Fatal(err)
	}
	node.Gossip.SetResolvers([]resolver.Resolver{r})
	if err := network.StartNode(node); err != nil {
		t.Fatal(err)
	}

	// Wait for a bit to ensure no connection.
	select {
	case <-time.After(10 * time.Millisecond):
		// expected outcome...
	case <-node.Gossip.Connected:
		t.Fatal("unexpectedly connected to gossip")
	}

	// Give the new node storage with info established from a node
	// in the established network.
	var ts2 testStorage
	if err := stores[0].ReadBootstrapInfo(&ts2.info); err != nil {
		t.Fatal(err)
	}
	if err := node.Gossip.SetStorage(&ts2); err != nil {
		t.Fatal(err)
	}

	network.SimulateNetwork(func(cycle int, network *simulation.Network) bool {
		if cycle > 1000 {
			t.Fatal("failed to connect to gossip")
		}
		select {
		case <-node.Gossip.Connected:
			return false
		default:
			return true
		}
	})

	testutils.SucceedsSoon(t, func() error {
		if expected, actual := len(network.Nodes)-1 /* -1 is ourself */, ts2.Len(); expected != actual {
			return errors.Errorf("expected %v, got %v (info: %#v)", expected, actual, ts2.Info().Addresses)
		}
		return nil
	})
}