aboutsummaryrefslogtreecommitdiffstats
path: root/integration_test/consensus_test.go
blob: 6bdc3dc92c818da85be861b12adc7b90aed9bba9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.

package integration

import (
    "context"
    "fmt"
    "sync"
    "testing"
    "time"

    "github.com/dexon-foundation/dexon-consensus/common"
    "github.com/dexon-foundation/dexon-consensus/core"
    "github.com/dexon-foundation/dexon-consensus/core/crypto"
    "github.com/dexon-foundation/dexon-consensus/core/db"
    "github.com/dexon-foundation/dexon-consensus/core/syncer"
    "github.com/dexon-foundation/dexon-consensus/core/test"
    "github.com/dexon-foundation/dexon-consensus/core/types"
    "github.com/dexon-foundation/dexon-consensus/core/utils"
    "github.com/stretchr/testify/suite"
)

// There is no scheduler in these tests, we need to wait a long period to make
// sure these tests are ok.
type ConsensusTestSuite struct {
    suite.Suite
}

// A round event handler to purge utils.NodeSetCache in test.Network.
func purgeHandlerGen(n *test.Network) func([]utils.RoundEventParam) {
    return func(evts []utils.RoundEventParam) {
        for _, e := range evts {
            if e.Reset == 0 {
                continue
            }
            n.PurgeNodeSetCache(e.Round + 1)
        }
    }
}

func govHandlerGen(
    round, reset uint64,
    g *test.Governance,
    doer func(*test.Governance)) func([]utils.RoundEventParam) {
    return func(evts []utils.RoundEventParam) {
        for _, e := range evts {
            if e.Round == round && e.Reset == reset {
                doer(g)
            }
        }
    }

}

type node struct {
    ID      types.NodeID
    con     *core.Consensus
    app     *test.App
    gov     *test.Governance
    rEvt    *utils.RoundEvent
    db      db.Database
    network *test.Network
    logger  common.Logger
}

func prohibitDKG(gov *test.Governance) {
    gov.Prohibit(test.StateAddDKGMasterPublicKey)
    gov.Prohibit(test.StateAddDKGFinal)
    gov.Prohibit(test.StateAddDKGComplaint)
}

func prohibitDKGExceptFinalize(gov *test.Governance) {
    gov.Prohibit(test.StateAddDKGMasterPublicKey)
    gov.Prohibit(test.StateAddDKGComplaint)
}

func unprohibitDKG(gov *test.Governance) {
    gov.Unprohibit(test.StateAddDKGMasterPublicKey)
    gov.Unprohibit(test.StateAddDKGFinal)
    gov.Unprohibit(test.StateAddDKGComplaint)
}

func (s *ConsensusTestSuite) setupNodes(
    dMoment time.Time,
    prvKeys []crypto.PrivateKey,
    seedGov *test.Governance) map[types.NodeID]*node {
    var (
        wg        sync.WaitGroup
        initRound uint64
    )
    // Setup peer server at transport layer.
    server := test.NewFakeTransportServer()
    serverChannel, err := server.Host()
    s.Require().NoError(err)
    // setup nodes.
    nodes := make(map[types.NodeID]*node)
    wg.Add(len(prvKeys))
    for _, k := range prvKeys {
        dbInst, err := db.NewMemBackedDB()
        s.Require().NoError(err)
        // Prepare essential modules: app, gov, db.
        networkModule := test.NewNetwork(k.PublicKey(), test.NetworkConfig{
            Type:          test.NetworkTypeFake,
            DirectLatency: &test.FixedLatencyModel{},
            GossipLatency: &test.FixedLatencyModel{},
            Marshaller:    test.NewDefaultMarshaller(nil)},
        )
        gov := seedGov.Clone()
        gov.SwitchToRemoteMode(networkModule)
        gov.NotifyRound(initRound, 0)
        networkModule.AttachNodeSetCache(utils.NewNodeSetCache(gov))
        logger := &common.NullLogger{}
        rEvt, err := utils.NewRoundEvent(context.Background(), gov, logger, 0,
            0, core.ConfigRoundShift)
        s.Require().NoError(err)
        nID := types.NewNodeID(k.PublicKey())
        nodes[nID] = &node{
            ID:      nID,
            app:     test.NewApp(initRound+1, gov, rEvt),
            gov:     gov,
            db:      dbInst,
            logger:  logger,
            rEvt:    rEvt,
            network: networkModule,
        }
        go func() {
            defer wg.Done()
            s.Require().NoError(networkModule.Setup(serverChannel))
            go networkModule.Run()
        }()
    }
    // Make sure transport layer is ready.
    s.Require().NoError(server.WaitForPeers(uint32(len(prvKeys))))
    wg.Wait()
    for _, k := range prvKeys {
        node := nodes[types.NewNodeID(k.PublicKey())]
        // Now is the consensus module.
        node.con = core.NewConsensus(
            dMoment,
            node.app,
            node.gov,
            node.db,
            node.network,
            k,
            node.logger,
        )
    }
    return nodes
}

func (s *ConsensusTestSuite) verifyNodes(nodes map[types.NodeID]*node) {
    for ID, node := range nodes {
        s.Require().NoError(test.VerifyDB(node.db))
        s.Require().NoError(node.app.Verify())
        for otherID, otherNode := range nodes {
            if ID == otherID {
                continue
            }
            s.Require().NoError(node.app.Compare(otherNode.app))
        }
    }
}

func (s *ConsensusTestSuite) syncBlocksWithSomeNode(
    sourceNode, syncNode *node,
    syncerObj *syncer.Consensus,
    nextSyncHeight uint64) (
    syncedCon *core.Consensus, syncerHeight uint64, err error) {

    syncerHeight = nextSyncHeight
    // Setup revealer.
    DBAll, err := sourceNode.db.GetAllBlocks()
    if err != nil {
        return
    }
    r, err := test.NewCompactionChainBlockRevealer(DBAll, nextSyncHeight)
    if err != nil {
        return
    }
    // Load all blocks from revealer and dump them into syncer.
    var compactionChainBlocks []*types.Block
    syncBlocks := func() (done bool) {
        // Apply txs in blocks to make sure our governance instance is ready.
        // This action should be performed by fullnode in production mode.
        for _, b := range compactionChainBlocks {
            if err = syncNode.gov.State().Apply(b.Payload); err != nil {
                if err != test.ErrDuplicatedChange {
                    return
                }
                err = nil
            }
            // Sync app.
            syncNode.app.BlockConfirmed(*b)
            syncNode.app.BlockDelivered(b.Hash, b.Position, b.Finalization)
            // Sync gov.
            syncNode.gov.CatchUpWithRound(
                b.Position.Round + core.ConfigRoundShift)
        }
        var synced bool
        synced, err = syncerObj.SyncBlocks(compactionChainBlocks, true)
        if err != nil {
            done = true
        }
        if synced {
            syncedCon, err = syncerObj.GetSyncedConsensus()
            done = true
        }
        compactionChainBlocks = nil
        return
    }
    for {
        var b types.Block
        b, err = r.NextBlock()
        if err != nil {
            if err == db.ErrIterationFinished {
                err = nil
                if syncBlocks() {
                    break
                }
            }
            break
        }
        syncerHeight = b.Finalization.Height + 1
        compactionChainBlocks = append(compactionChainBlocks, &b)
        if len(compactionChainBlocks) >= 20 {
            if syncBlocks() {
                break
            }
        }
    }
    return
}

func (s *ConsensusTestSuite) TestSimple() {
    // The simplest test case:
    //  - Node set is equals to DKG set and notary set for each chain in each
    //    round.
    //  - No configuration change.
    //  - 4 rounds (0, 1 are genesis rounds, round 2 would be ready when the
    //    first block delivered. Test until round 3 should be enough.
    var (
        req        = s.Require()
        peerCount  = 4
        dMoment    = time.Now().UTC()
        untilRound = uint64(5)
    )
    if testing.Short() {
        untilRound = 2
    }
    prvKeys, pubKeys, err := test.NewKeys(peerCount)
    req.NoError(err)
    // Setup seed governance instance. Give a short latency to make this test
    // run faster.
    seedGov, err := test.NewGovernance(
        test.NewState(core.DKGDelayRound,
            pubKeys, 100*time.Millisecond, &common.NullLogger{}, true),
        core.ConfigRoundShift)
    req.NoError(err)
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    // A short round interval.
    nodes := s.setupNodes(dMoment, prvKeys, seedGov)
    for _, n := range nodes {
        go n.con.Run()
        defer n.con.Stop()
    }
Loop:
    for {
        <-time.After(5 * time.Second)
        for _, n := range nodes {
            latestPos := n.app.GetLatestDeliveredPosition()
            fmt.Println("latestPos", n.ID, &latestPos)
            if latestPos.Round < untilRound {
                continue Loop
            }
        }
        // Oh ya.
        break
    }
    s.verifyNodes(nodes)
}

func (s *ConsensusTestSuite) TestSetSizeChange() {
    var (
        req        = s.Require()
        peerCount  = 7
        dMoment    = time.Now().UTC()
        untilRound = uint64(5)
    )
    if testing.Short() {
        // Short test won't test configuration change packed as payload of
        // blocks and applied when delivered.
        untilRound = 5
    }
    prvKeys, pubKeys, err := test.NewKeys(peerCount)
    req.NoError(err)
    // Setup seed governance instance.
    seedGov, err := test.NewGovernance(
        test.NewState(core.DKGDelayRound, pubKeys, 100*time.Millisecond, &common.NullLogger{}, true),
        core.ConfigRoundShift)
    req.NoError(err)
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeNotarySetSize, uint32(4)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeDKGSetSize, uint32(4)))
    seedGov.CatchUpWithRound(0)
    // Setup configuration for round 0 and round 1.
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeNotarySetSize, uint32(5)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeDKGSetSize, uint32(6)))
    seedGov.CatchUpWithRound(1)
    // Setup configuration for round 2.
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeNotarySetSize, uint32(6)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeDKGSetSize, uint32(5)))
    seedGov.CatchUpWithRound(2)
    // Setup configuration for round 3.
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeNotarySetSize, uint32(4)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeDKGSetSize, uint32(4)))
    seedGov.CatchUpWithRound(3)
    // Setup nodes.
    nodes := s.setupNodes(dMoment, prvKeys, seedGov)
    // Pick master node, and register changes on it.
    var pickedNode *node
    for _, pickedNode = range nodes {
        break
    }
    // Register configuration changes for round 4.
    req.NoError(pickedNode.gov.RegisterConfigChange(
        4, test.StateChangeRoundLength, uint64(100)))
    req.NoError(pickedNode.gov.RegisterConfigChange(
        4, test.StateChangeNotarySetSize, uint32(5)))
    req.NoError(pickedNode.gov.RegisterConfigChange(
        4, test.StateChangeDKGSetSize, uint32(5)))
    // Run test.
    for _, n := range nodes {
        go n.con.Run()
        defer n.con.Stop()
    }
Loop:
    for {
        <-time.After(5 * time.Second)
        for _, n := range nodes {
            latestPos := n.app.GetLatestDeliveredPosition()
            fmt.Println("latestPos", n.ID, &latestPos)
            if latestPos.Round < untilRound {
                continue Loop
            }
        }
        // Oh ya.
        break
    }
    s.verifyNodes(nodes)
}

func (s *ConsensusTestSuite) TestSync() {
    // The sync test case:
    // - No configuration change.
    // - One node does not run when all others starts until aliveRound exceeded.
    // - One DKG reset happened before syncing.
    var (
        req        = s.Require()
        peerCount  = 4
        dMoment    = time.Now().UTC()
        untilRound = uint64(6)
        stopRound  = uint64(4)
        // aliveRound should be large enough to test round event handling in
        // syncer.
        aliveRound = uint64(2)
        errChan    = make(chan error, 100)
    )
    prvKeys, pubKeys, err := test.NewKeys(peerCount)
    req.NoError(err)
    // Setup seed governance instance. Give a short latency to make this test
    // run faster.
    seedGov, err := test.NewGovernance(
        test.NewState(core.DKGDelayRound,
            pubKeys, 100*time.Millisecond, &common.NullLogger{}, true),
        core.ConfigRoundShift)
    req.NoError(err)
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    seedGov.CatchUpWithRound(0)
    seedGov.CatchUpWithRound(1)
    // A short round interval.
    nodes := s.setupNodes(dMoment, prvKeys, seedGov)
    // Choose the first node as "syncNode" that its consensus' Run() is called
    // later.
    syncNode := nodes[types.NewNodeID(pubKeys[0])]
    syncNode.con = nil
    // Pick a node to stop when synced.
    stoppedNode := nodes[types.NewNodeID(pubKeys[1])]
    for _, n := range nodes {
        n.rEvt.Register(purgeHandlerGen(n.network))
        // Round Height reference table:
        // - Round:1 Reset:0 -- 100
        // - Round:1 Reset:1 -- 200
        // - Round:2 Reset:0 -- 300
        n.rEvt.Register(govHandlerGen(1, 0, n.gov, prohibitDKG))
        n.rEvt.Register(govHandlerGen(1, 1, n.gov, unprohibitDKG))
        if n.ID != syncNode.ID {
            go n.con.Run()
            if n.ID != stoppedNode.ID {
                defer n.con.Stop()
            }
        }
    }
    // Clean syncNode's network receive channel, or it might exceed the limit
    // and block other go routines.
    dummyReceiverCtxCancel, dummyFinished := utils.LaunchDummyReceiver(
        context.Background(), syncNode.network.ReceiveChan(), nil)
ReachAlive:
    for {
        // Check if any error happened or sleep for a period of time.
        select {
        case err := <-errChan:
            req.NoError(err)
        case <-time.After(5 * time.Second):
        }
        // If all nodes excepts syncNode have reached aliveRound, call syncNode's
        // Run() and send it all blocks in one of normal node's compaction chain.
        for id, n := range nodes {
            if id == syncNode.ID {
                continue
            }
            pos := n.app.GetLatestDeliveredPosition()
            if pos.Round < aliveRound {
                fmt.Println("latestPos", n.ID, &pos)
                continue ReachAlive
            }
        }
        dummyReceiverCtxCancel()
        <-dummyFinished
        break
    }
    // Initiate Syncer.
    runnerCtx, runnerCtxCancel := context.WithCancel(context.Background())
    defer runnerCtxCancel()
    syncerObj := syncer.NewConsensus(
        dMoment,
        syncNode.app,
        syncNode.gov,
        syncNode.db,
        syncNode.network,
        prvKeys[0],
        &common.NullLogger{},
    )
    // Initialize communication channel, it's not recommended to assertion in
    // another go routine.
    go func() {
        var (
            syncedHeight uint64
            err          error
            syncedCon    *core.Consensus
        )
    SyncLoop:
        for {
            syncedCon, syncedHeight, err = s.syncBlocksWithSomeNode(
                stoppedNode, syncNode, syncerObj, syncedHeight)
            if syncedCon != nil {
                syncNode.con = syncedCon
                go syncNode.con.Run()
                go func() {
                    <-runnerCtx.Done()
                    syncNode.con.Stop()
                }()
                break SyncLoop
            }
            if err != nil {
                errChan <- err
                break SyncLoop
            }
            select {
            case <-runnerCtx.Done():
                break SyncLoop
            case <-time.After(4 * time.Second):
            }
        }
    }()
    // Wait until all nodes reach 'untilRound'.
    var stoppedRound uint64
    go func() {
        n, pos := stoppedNode, stoppedNode.app.GetLatestDeliveredPosition()
    ReachFinished:
        for {
            fmt.Println("latestPos", n.ID, &pos)
            time.Sleep(5 * time.Second)
            if stoppedNode.con != nil {
                pos = n.app.GetLatestDeliveredPosition()
                if pos.Round >= stopRound {
                    // Stop a node, we should still be able to proceed.
                    stoppedNode.con.Stop()
                    stoppedNode.con = nil
                    stoppedRound = pos.Round
                    fmt.Println("one node stopped", stoppedNode.ID)
                    utils.LaunchDummyReceiver(
                        runnerCtx, stoppedNode.network.ReceiveChan(), nil)
                }
            }
            for _, n = range nodes {
                if n.ID == stoppedNode.ID {
                    continue
                }
                pos = n.app.GetLatestDeliveredPosition()
                if pos.Round < untilRound {
                    continue ReachFinished
                }
            }
            break
        }
        runnerCtxCancel()
    }()
    // Block until any reasonable testing milestone reached.
    select {
    case err := <-errChan:
        req.NoError(err)
    case <-runnerCtx.Done():
        // This test passed.
    }
    s.Require().Equal(stoppedRound, stopRound)
}

func (s *ConsensusTestSuite) TestForceSync() {
    // The sync test case:
    // - No configuration change.
    // - One node does not run when all others starts until aliveRound exceeded.
    var (
        req        = s.Require()
        peerCount  = 4
        dMoment    = time.Now().UTC()
        untilRound = uint64(3)
        stopRound  = uint64(1)
        errChan    = make(chan error, 100)
    )
    prvKeys, pubKeys, err := test.NewKeys(peerCount)
    req.NoError(err)
    // Setup seed governance instance. Give a short latency to make this test
    // run faster.
    seedGov, err := test.NewGovernance(
        test.NewState(core.DKGDelayRound,
            pubKeys, 100*time.Millisecond, &common.NullLogger{}, true),
        core.ConfigRoundShift)
    req.NoError(err)
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    seedGov.CatchUpWithRound(0)
    seedGov.CatchUpWithRound(1)
    // A short round interval.
    nodes := s.setupNodes(dMoment, prvKeys, seedGov)
    for _, n := range nodes {
        go n.con.Run()
    }
ReachStop:
    for {
        // Check if any error happened or sleep for a period of time.
        select {
        case err := <-errChan:
            req.NoError(err)
        case <-time.After(5 * time.Second):
        }
        // If one of the nodes have reached stopRound, stop all nodes to simulate
        // crash.
        for _, n := range nodes {
            pos := n.app.GetLatestDeliveredPosition()
            if pos.Round >= stopRound {
                break ReachStop
            } else {
                fmt.Println("latestPos", n.ID, &pos)
            }
        }
    }

    var latestHeight uint64
    var latestNodeID types.NodeID
    for _, n := range nodes {
        n.con.Stop()
        time.Sleep(1 * time.Second)
    }
    for nID, n := range nodes {
        _, height := n.db.GetCompactionChainTipInfo()
        if height > latestHeight {
            fmt.Println("Newer height", nID, height)
            latestNodeID = nID
            latestHeight = height
        }
    }
    fmt.Println("Latest node", latestNodeID, latestHeight)
    for nID, node := range nodes {
        if nID == latestNodeID {
            continue
        }
        fmt.Printf("[%p] Clearing %s %s\n", node.app, nID, node.app.GetLatestDeliveredPosition())
        node.app.ClearUndeliveredBlocks()
    }
    syncerCon := make(map[types.NodeID]*syncer.Consensus, len(nodes))
    for _, prvKey := range prvKeys {
        nID := types.NewNodeID(prvKey.PublicKey())
        node := nodes[nID]
        syncerCon[nID] = syncer.NewConsensus(
            dMoment,
            node.app,
            node.gov,
            node.db,
            node.network,
            prvKey,
            &common.NullLogger{},
        )
    }
    targetNode := nodes[latestNodeID]
    for nID, node := range nodes {
        syncedHeight := node.app.GetLatestDeliveredPosition().Height + 1
        // FinalizationHeight = Height + 1
        syncedHeight++
        var err error
        for {
            fmt.Println("Syncing", nID, syncedHeight)
            if syncedHeight >= latestHeight {
                break
            }
            _, syncedHeight, err = s.syncBlocksWithSomeNode(
                targetNode, node, syncerCon[nID], syncedHeight)
            if err != nil {
                panic(err)
            }
            fmt.Println("Syncing after", nID, syncedHeight)
        }
        fmt.Println("Synced", nID, syncedHeight)
    }
    // Make sure all nodes are synced in db and app.
    _, latestHeight = targetNode.db.GetCompactionChainTipInfo()
    latestPos := targetNode.app.GetLatestDeliveredPosition()
    for _, node := range nodes {
        _, height := node.db.GetCompactionChainTipInfo()
        s.Require().Equal(height, latestHeight)
        pos := node.app.GetLatestDeliveredPosition()
        s.Require().Equal(latestPos, pos)
    }
    for _, con := range syncerCon {
        con.ForceSync(true)
    }
    for nID := range nodes {
        con, err := syncerCon[nID].GetSyncedConsensus()
        s.Require().NoError(err)
        nodes[nID].con = con
    }
    for _, node := range nodes {
        go node.con.Run()
        defer node.con.Stop()
    }

Loop:
    for {
        <-time.After(5 * time.Second)
        for _, n := range nodes {
            latestPos := n.app.GetLatestDeliveredPosition()
            fmt.Println("latestPos", n.ID, &latestPos)
            if latestPos.Round < untilRound {
                continue Loop
            }
        }
        // Oh ya.
        break
    }
    s.verifyNodes(nodes)
}

func (s *ConsensusTestSuite) TestResetDKG() {
    var (
        req        = s.Require()
        peerCount  = 5
        dMoment    = time.Now().UTC()
        untilRound = uint64(3)
    )
    prvKeys, pubKeys, err := test.NewKeys(peerCount)
    req.NoError(err)
    // Setup seed governance instance. Give a short latency to make this test
    // run faster.
    seedGov, err := test.NewGovernance(
        test.NewState(core.DKGDelayRound,
            pubKeys, 100*time.Millisecond, &common.NullLogger{}, true),
        core.ConfigRoundShift)
    req.NoError(err)
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeRoundLength, uint64(100)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeNotarySetSize, uint32(4)))
    req.NoError(seedGov.State().RequestChange(
        test.StateChangeDKGSetSize, uint32(4)))
    nodes := s.setupNodes(dMoment, prvKeys, seedGov)
    for _, n := range nodes {
        n.rEvt.Register(purgeHandlerGen(n.network))
        // Round Height reference table:
        // - Round:1 Reset:0 -- 100
        // - Round:1 Reset:1 -- 200
        // - Round:1 Reset:2 -- 300
        // - Round:2 Reset:0 -- 400
        // - Round:2 Reset:1 -- 500
        // - Round:3 Reset:0 -- 600
        n.rEvt.Register(govHandlerGen(1, 0, n.gov, prohibitDKG))
        n.rEvt.Register(govHandlerGen(1, 2, n.gov, unprohibitDKG))
        n.rEvt.Register(govHandlerGen(2, 0, n.gov, prohibitDKGExceptFinalize))
        n.rEvt.Register(govHandlerGen(2, 1, n.gov, unprohibitDKG))
        go n.con.Run()
    }
Loop:
    for {
        <-time.After(5 * time.Second)
        for _, n := range nodes {
            latestPos := n.app.GetLatestDeliveredPosition()
            fmt.Println("latestPos", n.ID, &latestPos)
            if latestPos.Round < untilRound {
                continue Loop
            }
        }
        // Oh ya.
        break
    }
    s.verifyNodes(nodes)
    for _, n := range nodes {
        n.con.Stop()
        req.Equal(n.gov.DKGResetCount(2), uint64(2))
        req.Equal(n.gov.DKGResetCount(3), uint64(1))
    }
}

func TestConsensus(t *testing.T) {
    suite.Run(t, new(ConsensusTestSuite))
}