Do not run DBSync if there is already a readable app version (#130)

internal/dbsync/reactor.go

@@ -107,6 +107,7 @@ type Reactor struct {
 	stateStore    sm.Store
 	blockStore    *store.BlockStore
 	initialHeight int64
+	shouldSync    bool
 
 	chainID       string
 	config        config.DBSyncConfig
@@ -138,6 +139,7 @@ func NewReactor(
 	initialHeight int64,
 	chainID string,
 	eventBus *eventbus.EventBus,
+	shouldSync bool,
 	postSyncHook func(context.Context, sm.State) error,
 ) *Reactor {
 	reactor := &Reactor{
@@ -152,8 +154,9 @@ func NewReactor(
 		eventBus:      eventBus,
 		config:        config,
 		postSyncHook:  postSyncHook,
+		shouldSync:    shouldSync,
 	}
-	syncer := NewSyncer(logger, config, baseConfig, reactor.requestMetadata, reactor.requestFile, reactor.commitState, reactor.postSync, defaultResetDirFn)
+	syncer := NewSyncer(logger, config, baseConfig, shouldSync, reactor.requestMetadata, reactor.requestFile, reactor.commitState, reactor.postSync, defaultResetDirFn)
 	reactor.syncer = syncer
 
 	reactor.BaseService = *service.NewBaseService(logger, "DBSync", reactor)
@@ -187,7 +190,7 @@ func (r *Reactor) OnStart(ctx context.Context) error {
 	go r.processFileCh(ctx, r.fileChannel)
 	go r.processLightBlockCh(ctx, r.lightBlockChannel)
 	go r.processParamsCh(ctx, r.paramsChannel)
-	if r.config.Enable {
+	if r.shouldSync {
 		to := light.TrustOptions{
 			Period: r.config.TrustPeriod,
 			Height: r.config.TrustHeight,

internal/dbsync/syncer.go

@@ -70,6 +70,7 @@ func NewSyncer(
 	logger log.Logger,
 	dbsyncConfig config.DBSyncConfig,
 	baseConfig config.BaseConfig,
+	enable bool,
 	metadataRequestFn func(context.Context) error,
 	fileRequestFn func(context.Context, types.NodeID, uint64, string) error,
 	commitStateFn func(context.Context, uint64) (sm.State, *types.Commit, error),
@@ -78,7 +79,7 @@ func NewSyncer(
 ) *Syncer {
 	return &Syncer{
 		logger:                 logger,
-		active:                 dbsyncConfig.Enable,
+		active:                 enable,
 		timeoutInSeconds:       time.Duration(dbsyncConfig.TimeoutInSeconds) * time.Second,
 		fileQueue:              []*dstypes.FileResponse{},
 		applicationDBDirectory: path.Join(baseConfig.DBDir(), ApplicationDBSubdirectory),

internal/dbsync/syncer_test.go

@@ -24,6 +24,7 @@ func getTestSyncer(t *testing.T) *Syncer {
 		log.NewNopLogger(),
 		*dbsyncConfig,
 		baseConfig,
+		true,
 		func(ctx context.Context) error { return nil },
 		func(ctx context.Context, ni types.NodeID, u uint64, s string) error { return nil },
 		func(ctx context.Context, u uint64) (state.State, *types.Commit, error) {

node/node.go

@@ -282,10 +282,16 @@ func makeNode(
 	node.rpcEnv.EvidencePool = evPool
 	node.evPool = evPool
 
+	info, err := client.Info(ctx, &abci.RequestInfo{})
+	if err != nil {
+		return nil, err
+	}
+	shoulddbsync := cfg.DBSync.Enable && info.LastBlockHeight == 0
+
 	mpReactor, mp := createMempoolReactor(logger, cfg, proxyApp, stateStore, nodeMetrics.mempool,
 		peerManager.Subscribe, peerManager)
 	node.router.AddChDescToBeAdded(mempool.GetChannelDescriptor(cfg.Mempool), mpReactor.SetChannel)
-	if !cfg.DBSync.Enable {
+	if !shoulddbsync {
 		mpReactor.MarkReadyToStart()
 	}
 	node.rpcEnv.Mempool = mp
@@ -310,14 +316,14 @@ func makeNode(
 		stateSync = false
 	}
 
-	if stateSync && cfg.DBSync.Enable {
+	if stateSync && shoulddbsync {
 		panic("statesync and dbsync cannot be turned on at the same time")
 	}
 
 	// Determine whether we should do block sync. This must happen after the handshake, since the
 	// app may modify the validator set, specifying ourself as the only validator.
 	blockSync := !onlyValidatorIsUs(state, pubKey)
-	waitSync := stateSync || blockSync || cfg.DBSync.Enable
+	waitSync := stateSync || blockSync || shoulddbsync
 
 	csState, err := consensus.NewState(logger.With("module", "consensus"),
 		cfg.Consensus,
@@ -361,7 +367,7 @@ func makeNode(
 		blockStore,
 		csReactor,
 		peerManager.Subscribe,
-		blockSync && !stateSync && !cfg.DBSync.Enable,
+		blockSync && !stateSync && !shoulddbsync,
 		nodeMetrics.consensus,
 		eventBus,
 		restartCh,
@@ -429,7 +435,7 @@ func makeNode(
 		cfg.SelfRemediation,
 	)
 
-	node.shouldHandshake = !stateSync && !cfg.DBSync.Enable
+	node.shouldHandshake = !stateSync && !shoulddbsync
 	node.services = append(node.services, ssReactor)
 	node.router.AddChDescToBeAdded(statesync.GetSnapshotChannelDescriptor(), ssReactor.SetSnapshotChannel)
 	node.router.AddChDescToBeAdded(statesync.GetChunkChannelDescriptor(), ssReactor.SetChunkChannel)
@@ -446,6 +452,7 @@ func makeNode(
 		genDoc.InitialHeight,
 		genDoc.ChainID,
 		eventBus,
+		shoulddbsync,
 		func(ctx context.Context, state sm.State) error {
 			if _, err := client.LoadLatest(ctx, &abci.RequestLoadLatest{}); err != nil {
 				return err