Golang util.SucceedsWithin函数代码示例

// TestReplicateRange verifies basic replication functionality by creating two stores
// and a range, replicating the range to the second store, and reading its data there.
func TestReplicateRange(t *testing.T) {
	defer leaktest.AfterTest(t)
	mtc := multiTestContext{}
	mtc.Start(t, 2)
	defer mtc.Stop()

	// Issue a command on the first node before replicating.
	incArgs, incResp := incrementArgs([]byte("a"), 5, 1, mtc.stores[0].StoreID())
	if err := mtc.stores[0].ExecuteCmd(context.Background(), proto.Call{Args: incArgs, Reply: incResp}); err != nil {
		t.Fatal(err)
	}

	rng, err := mtc.stores[0].GetRange(1)
	if err != nil {
		t.Fatal(err)
	}

	if err := rng.ChangeReplicas(proto.ADD_REPLICA,
		proto.Replica{
			NodeID:  mtc.stores[1].Ident.NodeID,
			StoreID: mtc.stores[1].Ident.StoreID,
		}); err != nil {
		t.Fatal(err)
	}
	// Verify no intent remains on range descriptor key.
	key := keys.RangeDescriptorKey(rng.Desc().StartKey)
	desc := proto.RangeDescriptor{}
	if ok, err := engine.MVCCGetProto(mtc.stores[0].Engine(), key, mtc.stores[0].Clock().Now(), true, nil, &desc); !ok || err != nil {
		t.Fatalf("fetching range descriptor yielded %t, %s", ok, err)
	}
	// Verify that in time, no intents remain on meta addressing
	// keys, and that range descriptor on the meta records is correct.
	util.SucceedsWithin(t, 1*time.Second, func() error {
		meta2 := keys.RangeMetaKey(proto.KeyMax)
		meta1 := keys.RangeMetaKey(meta2)
		for _, key := range []proto.Key{meta2, meta1} {
			metaDesc := proto.RangeDescriptor{}
			if ok, err := engine.MVCCGetProto(mtc.stores[0].Engine(), key, mtc.stores[0].Clock().Now(), true, nil, &metaDesc); !ok || err != nil {
				return util.Errorf("failed to resolve %s", key)
			}
			if !reflect.DeepEqual(metaDesc, desc) {
				return util.Errorf("descs not equal: %+v != %+v", metaDesc, desc)
			}
		}
		return nil
	})

	// Verify that the same data is available on the replica.
	util.SucceedsWithin(t, 1*time.Second, func() error {
		getArgs, getResp := getArgs([]byte("a"), 1, mtc.stores[1].StoreID())
		getArgs.ReadConsistency = proto.INCONSISTENT
		if err := mtc.stores[1].ExecuteCmd(context.Background(), proto.Call{Args: getArgs, Reply: getResp}); err != nil {
			return util.Errorf("failed to read data")
		}
		if v := mustGetInteger(getResp.Value); v != 5 {
			return util.Errorf("failed to read correct data: %d", v)
		}
		return nil
	})
}

// TestReplicateRange verifies basic replication functionality by creating two stores
// and a range, replicating the range to the second store, and reading its data there.
func TestReplicateRange(t *testing.T) {
	defer leaktest.AfterTest(t)
	mtc := startMultiTestContext(t, 2)
	defer mtc.Stop()

	// Issue a command on the first node before replicating.
	incArgs := incrementArgs([]byte("a"), 5)
	if _, err := client.SendWrapped(rg1(mtc.stores[0]), nil, &incArgs); err != nil {
		t.Fatal(err)
	}

	rng, err := mtc.stores[0].GetReplica(1)
	if err != nil {
		t.Fatal(err)
	}

	if err := rng.ChangeReplicas(roachpb.ADD_REPLICA,
		roachpb.ReplicaDescriptor{
			NodeID:  mtc.stores[1].Ident.NodeID,
			StoreID: mtc.stores[1].Ident.StoreID,
		}, rng.Desc()); err != nil {
		t.Fatal(err)
	}
	// Verify no intent remains on range descriptor key.
	key := keys.RangeDescriptorKey(rng.Desc().StartKey)
	desc := roachpb.RangeDescriptor{}
	if ok, err := engine.MVCCGetProto(mtc.stores[0].Engine(), key, mtc.stores[0].Clock().Now(), true, nil, &desc); !ok || err != nil {
		t.Fatalf("fetching range descriptor yielded %t, %s", ok, err)
	}
	// Verify that in time, no intents remain on meta addressing
	// keys, and that range descriptor on the meta records is correct.
	util.SucceedsWithin(t, 1*time.Second, func() error {
		meta2 := keys.Addr(keys.RangeMetaKey(roachpb.RKeyMax))
		meta1 := keys.Addr(keys.RangeMetaKey(meta2))
		for _, key := range []roachpb.RKey{meta2, meta1} {
			metaDesc := roachpb.RangeDescriptor{}
			if ok, err := engine.MVCCGetProto(mtc.stores[0].Engine(), key.AsRawKey(), mtc.stores[0].Clock().Now(), true, nil, &metaDesc); !ok || err != nil {
				return util.Errorf("failed to resolve %s", key.AsRawKey())
			}
			if !reflect.DeepEqual(metaDesc, desc) {
				return util.Errorf("descs not equal: %+v != %+v", metaDesc, desc)
			}
		}
		return nil
	})

	// Verify that the same data is available on the replica.
	util.SucceedsWithin(t, replicaReadTimeout, func() error {
		getArgs := getArgs([]byte("a"))
		if reply, err := client.SendWrappedWith(rg1(mtc.stores[1]), nil, roachpb.Header{
			ReadConsistency: roachpb.INCONSISTENT,
		}, &getArgs); err != nil {
			return util.Errorf("failed to read data: %s", err)
		} else if e, v := int64(5), mustGetInt(reply.(*roachpb.GetResponse).Value); v != e {
			return util.Errorf("failed to read correct data: expected %d, got %d", e, v)
		}
		return nil
	})
}

// TestStoreZoneUpdateAndRangeSplit verifies that modifying the zone
// configuration changes range max bytes and Range.maybeSplit() takes
// max bytes into account when deciding whether to enqueue a range for
// splitting. It further verifies that the range is in fact split on
// exceeding zone's RangeMaxBytes.
func TestStoreZoneUpdateAndRangeSplit(t *testing.T) {
	defer leaktest.AfterTest(t)
	store, stopper := createTestStore(t)
	config.TestingSetupZoneConfigHook(stopper)
	defer stopper.Stop()

	maxBytes := int64(1 << 16)
	// Set max bytes.
	descID := uint32(keys.MaxReservedDescID + 1)
	config.TestingSetZoneConfig(descID, &config.ZoneConfig{RangeMaxBytes: maxBytes})

	// Trigger gossip callback.
	if err := store.Gossip().AddInfoProto(gossip.KeySystemConfig, &config.SystemConfig{}, 0); err != nil {
		t.Fatal(err)
	}

	// Wait for the range to be split along table boundaries.
	originalRange := store.LookupReplica(roachpb.RKey(keys.UserTableDataMin), nil)
	var rng *storage.Replica
	util.SucceedsWithin(t, splitTimeout, func() error {
		rng = store.LookupReplica(keys.MakeTablePrefix(descID), nil)
		if rng.RangeID == originalRange.RangeID {
			return util.Errorf("expected new range created by split")
		}
		return nil
	})

	// Check range's max bytes settings.
	if rng.GetMaxBytes() != maxBytes {
		t.Fatalf("range max bytes mismatch, got: %d, expected: %d", rng.GetMaxBytes(), maxBytes)
	}

	// Make sure the second range goes to the end.
	if !roachpb.RKeyMax.Equal(rng.Desc().EndKey) {
		t.Fatalf("second range has split: %+v", rng.Desc())
	}

	// Look in the range after prefix we're writing to.
	fillRange(store, rng.RangeID, keys.MakeTablePrefix(descID), maxBytes, t)

	// Verify that the range is in fact split (give it a few seconds for very
	// slow test machines).
	var newRng *storage.Replica
	util.SucceedsWithin(t, splitTimeout, func() error {
		newRng = store.LookupReplica(keys.MakeTablePrefix(descID+1), nil)
		if newRng.RangeID == rng.RangeID {
			return util.Errorf("range has not yet split")
		}
		return nil
	})

	// Make sure the new range goes to the end.
	if !roachpb.RKeyMax.Equal(newRng.Desc().EndKey) {
		t.Fatalf("second range has split: %+v", rng.Desc())
	}
}

// TestStoreZoneUpdateAndRangeSplit verifies that modifying the zone
// configuration changes range max bytes and Range.maybeSplit() takes
// max bytes into account when deciding whether to enqueue a range for
// splitting. It further verifies that the range is in fact split on
// exceeding zone's RangeMaxBytes.
func TestStoreZoneUpdateAndRangeSplit(t *testing.T) {
	defer leaktest.AfterTest(t)
	store, stopper := createTestStore(t)
	config.TestingSetupZoneConfigHook(stopper)
	defer stopper.Stop()

	maxBytes := int64(1 << 16)
	// Set max bytes.
	descID := uint32(keys.MaxReservedDescID + 1)
	config.TestingSetZoneConfig(descID, &config.ZoneConfig{RangeMaxBytes: maxBytes})

	// Trigger gossip callback.
	if err := store.Gossip().AddInfoProto(gossip.KeySystemConfig, &config.SystemConfig{}, 0); err != nil {
		t.Fatal(err)
	}

	tableBoundary := keys.MakeTablePrefix(descID)

	{
		var rng *storage.Replica

		// Wait for the range to be split along table boundaries.
		expectedRSpan := roachpb.RSpan{Key: roachpb.RKey(tableBoundary), EndKey: roachpb.RKeyMax}
		util.SucceedsWithin(t, splitTimeout, func() error {
			rng = store.LookupReplica(tableBoundary, nil)
			if actualRSpan := rng.Desc().RSpan(); !actualRSpan.Equal(expectedRSpan) {
				return util.Errorf("expected range %s to span %s", rng, expectedRSpan)
			}
			return nil
		})

		// Check range's max bytes settings.
		if actualMaxBytes := rng.GetMaxBytes(); actualMaxBytes != maxBytes {
			t.Fatalf("range %s max bytes mismatch, got: %d, expected: %d", rng, actualMaxBytes, maxBytes)
		}

		// Look in the range after prefix we're writing to.
		fillRange(store, rng.RangeID, tableBoundary, maxBytes, t)
	}

	// Verify that the range is in fact split.
	util.SucceedsWithin(t, splitTimeout, func() error {
		rng := store.LookupReplica(keys.MakeTablePrefix(descID+1), nil)
		rngDesc := rng.Desc()
		rngStart, rngEnd := rngDesc.StartKey, rngDesc.EndKey
		if rngStart.Equal(tableBoundary) || !rngEnd.Equal(roachpb.RKeyMax) {
			return util.Errorf("range %s has not yet split", rng)
		}
		return nil
	})
}

// TestReplicaGCQueueDropReplica verifies that a removed replica is
// immediately cleaned up.
func TestReplicaGCQueueDropReplicaDirect(t *testing.T) {
	defer leaktest.AfterTest(t)
	mtc := &multiTestContext{}
	const numStores = 3
	rangeID := roachpb.RangeID(1)

	// In this test, the Replica on the second Node is removed, and the test
	// verifies that that Node adds this Replica to its RangeGCQueue. However,
	// the queue does a consistent lookup which will usually be read from
	// Node 1. Hence, if Node 1 hasn't processed the removal when Node 2 has,
	// no GC will take place since the consistent RangeLookup hits the first
	// Node. We use the TestingCommandFilter to make sure that the second Node
	// waits for the first.
	storage.TestingCommandFilter = func(id roachpb.StoreID, args roachpb.Request, _ roachpb.Header) error {
		et, ok := args.(*roachpb.EndTransactionRequest)
		if !ok || id != 2 {
			return nil
		}
		rct := et.InternalCommitTrigger.GetChangeReplicasTrigger()
		if rct == nil || rct.ChangeType != roachpb.REMOVE_REPLICA {
			return nil
		}
		util.SucceedsWithin(t, time.Second, func() error {
			r, err := mtc.stores[0].GetReplica(rangeID)
			if err != nil {
				return err
			}
			if i, _ := r.Desc().FindReplica(2); i >= 0 {
				return errors.New("expected second node gone from first node's known replicas")
			}
			return nil
		})
		return nil
	}

	defer func() { storage.TestingCommandFilter = nil }()

	mtc.Start(t, numStores)
	defer mtc.Stop()

	mtc.replicateRange(rangeID, 1, 2)
	mtc.unreplicateRange(rangeID, 1)

	// Make sure the range is removed from the store.
	util.SucceedsWithin(t, 10*time.Second, func() error {
		if _, err := mtc.stores[1].GetReplica(rangeID); !testutils.IsError(err, "range .* was not found") {
			return util.Errorf("expected range removal")
		}
		return nil
	})
}

// TestClientDisconnectRedundant verifies that the gossip server
// will drop an outgoing client connection that is already an
// inbound client connection of another node.
func TestClientDisconnectRedundant(t *testing.T) {
	defer leaktest.AfterTest(t)
	local, remote, stopper := startGossip(t)
	defer stopper.Stop()
	// startClient requires locks are held, so acquire here.
	local.mu.Lock()
	remote.mu.Lock()

	rAddr := remote.is.NodeAddr
	lAddr := local.is.NodeAddr
	local.startClient(rAddr, stopper)
	remote.startClient(lAddr, stopper)
	local.mu.Unlock()
	remote.mu.Unlock()
	local.manage(stopper)
	remote.manage(stopper)
	util.SucceedsWithin(t, 10*time.Second, func() error {
		// Check which of the clients is connected to the other.
		ok1 := local.findClient(func(c *client) bool { return c.addr.String() == rAddr.String() }) != nil
		ok2 := remote.findClient(func(c *client) bool { return c.addr.String() == lAddr.String() }) != nil
		// We expect node 1 to disconnect; if both are still connected,
		// it's possible that node 1 gossiped before node 2 connected, in
		// which case we have to gossip from node 1 to trigger the
		// disconnect redundant client code.
		if ok1 && ok2 {
			if err := local.AddInfo("local-key", nil, time.Second); err != nil {
				t.Fatal(err)
			}
		} else if !ok1 && ok2 && verifyServerMaps(local, 1) && verifyServerMaps(remote, 0) {
			return nil
		}
		return errors.New("local client to remote not yet closed as redundant")
	})
}

// TestRemoveRangeWithoutGC ensures that we do not panic when a
// replica has been removed but not yet GC'd (and therefore
// does not have an active raft group).
func TestRemoveRangeWithoutGC(t *testing.T) {
	defer leaktest.AfterTest(t)

	mtc := startMultiTestContext(t, 2)
	defer mtc.Stop()
	// Disable the GC queue and move the range from store 0 to 1.
	mtc.stores[0].DisableReplicaGCQueue(true)
	const rangeID roachpb.RangeID = 1
	mtc.replicateRange(rangeID, 1)
	mtc.unreplicateRange(rangeID, 0)

	// Wait for store 0 to process the removal.
	util.SucceedsWithin(t, time.Second, func() error {
		rep, err := mtc.stores[0].GetReplica(rangeID)
		if err != nil {
			return err
		}
		desc := rep.Desc()
		if len(desc.Replicas) != 1 {
			return util.Errorf("range has %d replicas", len(desc.Replicas))
		}
		return nil
	})

	// The replica's data is still on disk even though the Replica
	// object is removed.
	var desc roachpb.RangeDescriptor
	descKey := keys.RangeDescriptorKey(roachpb.RKeyMin)
	if ok, err := engine.MVCCGetProto(mtc.stores[0].Engine(), descKey,
		mtc.stores[0].Clock().Now(), true, nil, &desc); err != nil {
		t.Fatal(err)
	} else if !ok {
		t.Fatal("expected range descriptor to be present")
	}

	// Stop and restart the store to reset the replica's raftGroup
	// pointer to nil. As long as the store has not been restarted it
	// can continue to use its last known replica ID.
	mtc.stopStore(0)
	mtc.restartStore(0)
	// Turn off the GC queue to ensure that the replica is deleted at
	// startup instead of by the scanner. This is not 100% guaranteed
	// since the scanner could have already run at this point, but it
	// should be enough to prevent us from accidentally relying on the
	// scanner.
	mtc.stores[0].DisableReplicaGCQueue(true)

	// The Replica object is not recreated.
	if _, err := mtc.stores[0].GetReplica(rangeID); err == nil {
		t.Fatalf("expected replica to be missing")
	}

	// And the data is no longer on disk.
	if ok, err := engine.MVCCGetProto(mtc.stores[0].Engine(), descKey,
		mtc.stores[0].Clock().Now(), true, nil, &desc); err != nil {
		t.Fatal(err)
	} else if ok {
		t.Fatal("expected range descriptor to be absent")
	}
}

// checkGossip fetches the gossip infoStore from each node and invokes the given
// function. The test passes if the function returns 0 for every node,
// retrying for up to the given duration.
func checkGossip(t *testing.T, l *localcluster.Cluster, d time.Duration,
	f checkGossipFunc) {
	util.SucceedsWithin(t, d, func() error {
		select {
		case <-stopper:
			t.Fatalf("interrupted")
			return nil
		case e := <-l.Events:
			if log.V(1) {
				log.Infof("%+v", e)
			}
			return fmt.Errorf("event: %+v", e)
		case <-time.After(1 * time.Second):
		}

		for i, node := range l.Nodes {
			var m map[string]interface{}
			if err := node.GetJSON("", "/_status/gossip/local", &m); err != nil {
				return err
			}
			infos := m["infos"].(map[string]interface{})
			if err := f(infos); err != nil {
				return util.Errorf("node %d: %s", i, err)
			}
		}

		return nil
	})
}

// TestMetricsRecording verifies that Node statistics are periodically recorded
// as time series data.
func TestMetricsRecording(t *testing.T) {
	defer leaktest.AfterTest(t)
	tsrv := &TestServer{}
	tsrv.Ctx = NewTestContext()
	tsrv.Ctx.MetricsFrequency = 5 * time.Millisecond
	if err := tsrv.Start(); err != nil {
		t.Fatal(err)
	}
	defer tsrv.Stop()

	checkTimeSeriesKey := func(now int64, keyName string) error {
		key := ts.MakeDataKey(keyName, "", ts.Resolution10s, now)
		data := &proto.InternalTimeSeriesData{}
		return tsrv.db.GetProto(key, data)
	}

	// Verify that metrics for the current timestamp are recorded. This should
	// be true very quickly.
	util.SucceedsWithin(t, time.Second, func() error {
		now := tsrv.Clock().PhysicalNow()
		if err := checkTimeSeriesKey(now, "cr.store.livebytes.1"); err != nil {
			return err
		}
		if err := checkTimeSeriesKey(now, "cr.node.sys.allocbytes.1"); err != nil {
			return err
		}
		return nil
	})
}

func TestBuildInfo(t *testing.T) {
	c := StartCluster(t)
	defer c.AssertAndStop(t)

	checkGossip(t, c, 20*time.Second, hasPeers(c.NumNodes()))

	util.SucceedsWithin(t, 10*time.Second, func() error {
		select {
		case <-stopper:
			t.Fatalf("interrupted")
			return nil
		default:
		}
		var r struct {
			BuildInfo map[string]string
		}
		if err := getJSON(c.URL(0), "/_status/details/local", &r); err != nil {
			return err
		}
		for _, key := range []string{"goVersion", "tag", "time", "dependencies"} {
			if val, ok := r.BuildInfo[key]; !ok {
				t.Errorf("build info missing for \"%s\"", key)
			} else if val == "" {
				t.Errorf("build info not set for \"%s\"", key)
			}
		}
		return nil
	})
}

// TestClientDisallowMultipleConns verifies that the server disallows
// multiple connections from the same client node ID.
func TestClientDisallowMultipleConns(t *testing.T) {
	defer leaktest.AfterTest(t)
	stopper := stop.NewStopper()
	defer stopper.Stop()
	local := startGossip(1, stopper, t)
	remote := startGossip(2, stopper, t)
	local.mu.Lock()
	remote.mu.Lock()
	rAddr := remote.is.NodeAddr
	// Start two clients from local to remote. RPC client cache is
	// disabled via the context, so we'll start two different outgoing
	// connections.
	local.startClient(rAddr, stopper)
	local.startClient(rAddr, stopper)
	local.mu.Unlock()
	remote.mu.Unlock()
	local.manage()
	remote.manage()
	util.SucceedsWithin(t, 10*time.Second, func() error {
		// Verify that the remote server has only a single incoming
		// connection and the local server has only a single outgoing
		// connection.
		local.mu.Lock()
		remote.mu.Lock()
		outgoing := local.outgoing.len()
		incoming := remote.incoming.len()
		local.mu.Unlock()
		remote.mu.Unlock()
		if outgoing == 1 && incoming == 1 && verifyServerMaps(local, 0) && verifyServerMaps(remote, 1) {
			return nil
		}
		return util.Errorf("incorrect number of incoming (%d) or outgoing (%d) connections", incoming, outgoing)
	})
}

// TestStoreRangeSplitWithMaxBytesUpdate tests a scenario where a new
// zone config that updates the max bytes is set and triggers a range
// split.
func TestStoreRangeSplitWithMaxBytesUpdate(t *testing.T) {
	defer leaktest.AfterTest(t)
	store, stopper := createTestStore(t)
	config.TestingSetupZoneConfigHook(stopper)
	defer stopper.Stop()

	origRng := store.LookupReplica(roachpb.RKeyMin, nil)

	// Set max bytes.
	maxBytes := int64(1 << 16)
	config.TestingSetZoneConfig(1000, &config.ZoneConfig{RangeMaxBytes: maxBytes})

	// Trigger gossip callback.
	if err := store.Gossip().AddInfoProto(gossip.KeySystemConfig, &config.SystemConfig{}, 0); err != nil {
		t.Fatal(err)
	}

	// Verify that the range is split and the new range has the correct max bytes.
	util.SucceedsWithin(t, time.Second, func() error {
		newRng := store.LookupReplica(keys.MakeTablePrefix(1000), nil)
		if newRng.Desc().RangeID == origRng.Desc().RangeID {
			return util.Errorf("expected new range created by split")
		}
		if newRng.GetMaxBytes() != maxBytes {
			return util.Errorf("expected %d max bytes for the new range, but got %d",
				maxBytes, newRng.GetMaxBytes())
		}
		return nil
	})
}

func TestBuildInfo(t *testing.T) {
	if *numLocal == 0 {
		t.Skip("skipping since not run against local cluster")
	}
	l := cluster.CreateLocal(1, 1, *logDir, stopper) // intentionally using a local cluster
	l.Start()
	defer l.AssertAndStop(t)

	checkGossip(t, l, 20*time.Second, hasPeers(l.NumNodes()))

	util.SucceedsWithin(t, 10*time.Second, func() error {
		select {
		case <-stopper:
			t.Fatalf("interrupted")
			return nil
		case <-time.After(200 * time.Millisecond):
		}
		var r struct {
			BuildInfo map[string]string
		}
		if err := l.Nodes[0].GetJSON("", "/_status/details/local", &r); err != nil {
			return err
		}
		for _, key := range []string{"goVersion", "tag", "time", "dependencies"} {
			if val, ok := r.BuildInfo[key]; !ok {
				t.Errorf("build info missing for \"%s\"", key)
			} else if val == "" {
				t.Errorf("build info not set for \"%s\"", key)
			}
		}
		return nil
	})
}

// checkGossip fetches the gossip infoStore from each node and invokes the given
// function. The test passes if the function returns 0 for every node,
// retrying for up to the given duration.
func checkGossip(t *testing.T, c cluster.Cluster, d time.Duration,
	f checkGossipFunc) {
	util.SucceedsWithin(t, d, func() error {
		select {
		case <-stopper:
			t.Fatalf("interrupted")
			return nil
		case <-time.After(1 * time.Second):
		}

		for i := 0; i < c.NumNodes(); i++ {
			var m map[string]interface{}
			if err := getJSON(c.URL(i), "/_status/gossip/local", &m); err != nil {
				return err
			}
			infos, ok := m["infos"].(map[string]interface{})
			if !ok {
				return errors.New("no infos yet")
			}
			if err := f(infos); err != nil {
				return util.Errorf("node %d: %s", i, err)
			}
		}

		return nil
	})
}

// TestScannerTiming verifies that ranges are scanned, regardless
// of how many, to match scanInterval.
func TestScannerTiming(t *testing.T) {
	defer leaktest.AfterTest(t)
	const count = 3
	const runTime = 100 * time.Millisecond
	const maxError = 7500 * time.Microsecond
	durations := []time.Duration{
		15 * time.Millisecond,
		25 * time.Millisecond,
	}
	for i, duration := range durations {
		util.SucceedsWithin(t, 10*time.Second, func() error {
			ranges := newTestRangeSet(count, t)
			q := &testQueue{}
			s := newReplicaScanner(duration, 0, ranges)
			s.AddQueues(q)
			mc := hlc.NewManualClock(0)
			clock := hlc.NewClock(mc.UnixNano)
			stopper := stop.NewStopper()
			s.Start(clock, stopper)
			time.Sleep(runTime)
			stopper.Stop()

			avg := s.avgScan()
			log.Infof("%d: average scan: %s", i, avg)
			if avg.Nanoseconds()-duration.Nanoseconds() > maxError.Nanoseconds() ||
				duration.Nanoseconds()-avg.Nanoseconds() > maxError.Nanoseconds() {
				return util.Errorf("expected %s, got %s: exceeds max error of %s", duration, avg, maxError)
			}
			return nil
		})
	}
}