Update checked headers for new transformers

- If a header was marked as checked before a transformer was added to the watcher, mark all headers since the new transformer's starting block number as unchecked.
2019-08-26 16:43:14 -05:00 · 2019-08-26 16:43:14 -05:00 · 666ea1c325
commit 666ea1c325
parent d76be4962b
19 changed files with 538 additions and 49 deletions
--- a/cmd/composeAndExecute.go
+++ b/cmd/composeAndExecute.go
@ -170,7 +170,10 @@ func composeAndExecute() {
 	var wg syn.WaitGroup
 	if len(ethEventInitializers) > 0 {
 		ew := watcher.NewEventWatcher(&db, blockChain)
-		ew.AddTransformers(ethEventInitializers)
+		err := ew.AddTransformers(ethEventInitializers)
+		if err != nil {
+			LogWithCommand.Fatalf("failed to add event transformer initializers to watcher: %s", err.Error())
+		}
 		wg.Add(1)
 		go watchEthEvents(&ew, &wg)
 	}
--- a/cmd/execute.go
+++ b/cmd/execute.go
@ -114,7 +114,10 @@ func execute() {
 	var wg syn.WaitGroup
 	if len(ethEventInitializers) > 0 {
 		ew := watcher.NewEventWatcher(&db, blockChain)
-		ew.AddTransformers(ethEventInitializers)
+		err = ew.AddTransformers(ethEventInitializers)
+		if err != nil {
+			LogWithCommand.Fatalf("failed to add event transformer initializers to watcher: %s", err.Error())
+		}
 		wg.Add(1)
 		go watchEthEvents(&ew, &wg)
 	}
--- a/db/migrations/00029_create_checked_logs_table.sql
+++ b/db/migrations/00029_create_checked_logs_table.sql
@ -0,0 +1,12 @@
+-- +goose Up
+-- SQL in this section is executed when the migration is applied.
+CREATE TABLE public.checked_logs
+(
+    id               SERIAL PRIMARY KEY,
+    contract_address VARCHAR(42),
+    topic_zero       VARCHAR(66)
+);
+
+-- +goose Down
+-- SQL in this section is executed when the migration is rolled back.
+DROP TABLE public.checked_logs;
--- a/db/schema.sql
+++ b/db/schema.sql
@ -156,6 +156,37 @@ CREATE SEQUENCE public.checked_headers_id_seq
 ALTER SEQUENCE public.checked_headers_id_seq OWNED BY public.checked_headers.id;


+--
+-- Name: checked_logs; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.checked_logs (
+    id integer NOT NULL,
+    contract_address character varying(42),
+    topic_zero character varying(66)
+);
+
+
+--
+-- Name: checked_logs_id_seq; Type: SEQUENCE; Schema: public; Owner: -
+--
+
+CREATE SEQUENCE public.checked_logs_id_seq
+    AS integer
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+--
+-- Name: checked_logs_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: -
+--
+
+ALTER SEQUENCE public.checked_logs_id_seq OWNED BY public.checked_logs.id;
+
+
 --
 -- Name: eth_nodes; Type: TABLE; Schema: public; Owner: -
 --
@ -656,6 +687,13 @@ ALTER TABLE ONLY public.blocks ALTER COLUMN id SET DEFAULT nextval('public.block
 ALTER TABLE ONLY public.checked_headers ALTER COLUMN id SET DEFAULT nextval('public.checked_headers_id_seq'::regclass);


+--
+-- Name: checked_logs id; Type: DEFAULT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.checked_logs ALTER COLUMN id SET DEFAULT nextval('public.checked_logs_id_seq'::regclass);
+
+
 --
 -- Name: eth_nodes id; Type: DEFAULT; Schema: public; Owner: -
 --
@ -787,6 +825,14 @@ ALTER TABLE ONLY public.checked_headers
    ADD CONSTRAINT checked_headers_pkey PRIMARY KEY (id);


+--
+-- Name: checked_logs checked_logs_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.checked_logs
+    ADD CONSTRAINT checked_logs_pkey PRIMARY KEY (id);
+
+
 --
 -- Name: blocks eth_node_id_block_number_uc; Type: CONSTRAINT; Schema: public; Owner: -
 --
--- a/go.mod
+++ b/go.mod
@ -6,28 +6,44 @@ require (
 	github.com/allegro/bigcache v1.2.1 // indirect
 	github.com/aristanetworks/goarista v0.0.0-20190712234253-ed1100a1c015 // indirect
 	github.com/dave/jennifer v1.3.0
+	github.com/deckarep/golang-set v1.7.1 // indirect
+	github.com/edsrzf/mmap-go v1.0.0 // indirect
+	github.com/elastic/gosigar v0.10.4 // indirect
 	github.com/ethereum/go-ethereum v1.9.1
+	github.com/fjl/memsize v0.0.0-20190710130421-bcb5799ab5e5 // indirect
+	github.com/gballet/go-libpcsclite v0.0.0-20190607065134-2772fd86a8ff // indirect
+	github.com/gorilla/websocket v1.4.1 // indirect
 	github.com/graph-gophers/graphql-go v0.0.0-20190724201507-010347b5f9e6 // indirect
 	github.com/hashicorp/golang-lru v0.5.1
 	github.com/hpcloud/tail v1.0.0
+	github.com/huin/goupnp v1.0.0 // indirect
+	github.com/jackpal/go-nat-pmp v1.0.1 // indirect
 	github.com/jmoiron/sqlx v0.0.0-20181024163419-82935fac6c1a
 	github.com/karalabe/usb v0.0.0-20190819132248-550797b1cad8 // indirect
 	github.com/lib/pq v1.0.0
+	github.com/mattn/go-colorable v0.1.2 // indirect
 	github.com/mattn/go-isatty v0.0.9 // indirect
+	github.com/mattn/go-runewidth v0.0.4 // indirect
 	github.com/mitchellh/go-homedir v1.1.0
+	github.com/olekukonko/tablewriter v0.0.1 // indirect
 	github.com/onsi/ginkgo v1.7.0
 	github.com/onsi/gomega v1.4.3
 	github.com/pborman/uuid v1.2.0 // indirect
 	github.com/pressly/goose v2.6.0+incompatible
 	github.com/prometheus/tsdb v0.10.0 // indirect
+	github.com/rjeczalik/notify v0.9.2 // indirect
 	github.com/rs/cors v1.7.0 // indirect
 	github.com/sirupsen/logrus v1.2.0
 	github.com/spf13/cobra v0.0.3
 	github.com/spf13/viper v1.3.2
+	github.com/status-im/keycard-go v0.0.0-20190424133014-d95853db0f48 // indirect
 	github.com/steakknife/bloomfilter v0.0.0-20180922174646-6819c0d2a570 // indirect
 	github.com/steakknife/hamming v0.0.0-20180906055917-c99c65617cd3 // indirect
+	github.com/syndtr/goleveldb v1.0.0 // indirect
 	github.com/tyler-smith/go-bip39 v1.0.2 // indirect
+	github.com/wsddn/go-ecdh v0.0.0-20161211032359-48726bab9208 // indirect
 	golang.org/x/net v0.0.0-20190603091049-60506f45cf65
 	golang.org/x/sync v0.0.0-20190423024810-112230192c58
+	gopkg.in/olebedev/go-duktape.v3 v3.0.0-20190709231704-1e4459ed25ff // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7
 )
--- a/go.sum
+++ b/go.sum
@ -60,6 +60,7 @@ github.com/go-kit/kit v0.8.0 h1:Wz+5lgoB0kkuqLEc6NVmwRknTKP6dTGbSqvhZtBI/j0=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0 h1:8HUsc87TaSWLKwrnumgC8/YconD2fJQsRJAsWaPg2ic=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
+github.com/go-sql-driver/mysql v1.4.0 h1:7LxgVwFb2hIQtMm87NdgAVfXjnt4OePseqT1tKx+opk=
 github.com/go-sql-driver/mysql v1.4.0/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
 github.com/go-sql-driver/mysql v1.4.1 h1:g24URVg0OFbNUTx9qqY1IRZ9D9z3iPyi5zKhQZpNwpA=
 github.com/go-sql-driver/mysql v1.4.1/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
@ -67,9 +68,11 @@ github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/snappy v0.0.0-20180518054509-2e65f85255db/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/golang/snappy v0.0.1 h1:Qgr9rKW7uDUkrbSmQeiDsGa8SjGyCOGtuasMWwvp2P4=
 github.com/golang/snappy v0.0.1/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/google/uuid v1.0.0 h1:b4Gk+7WdP/d3HZH8EJsZpvV7EtDOgaZLtnaNGIu1adA=
@ -78,6 +81,8 @@ github.com/google/uuid v1.1.0 h1:Jf4mxPC/ziBnoPIdpQdPJ9OeiomAUHLvxmPRSPH9m4s=
 github.com/google/uuid v1.1.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/gorilla/websocket v1.4.1 h1:q7AeDBpnBk8AogcD4DSag/Ukw/KV+YhzLj2bP5HvKCM=
+github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/graph-gophers/graphql-go v0.0.0-20190610161739-8f92f34fc598/go.mod h1:Au3iQ8DvDis8hZ4q2OzRcaKYlAsPt+fYvib5q4nIqu4=
 github.com/graph-gophers/graphql-go v0.0.0-20190724201507-010347b5f9e6 h1:9WiNlI9Cds5S5YITwRpRs8edNaq0nxTEymhDW20A1QE=
 github.com/graph-gophers/graphql-go v0.0.0-20190724201507-010347b5f9e6/go.mod h1:Au3iQ8DvDis8hZ4q2OzRcaKYlAsPt+fYvib5q4nIqu4=
@ -132,6 +137,7 @@ github.com/mattn/go-isatty v0.0.9 h1:d5US/mDsogSGW37IV293h//ZFaeajb69h+EHFsv2xGg
 github.com/mattn/go-isatty v0.0.9/go.mod h1:YNRxwqDuOph6SZLI9vUUz6OYw3QyUt7WiY2yME+cCiQ=
 github.com/mattn/go-runewidth v0.0.4 h1:2BvfKmzob6Bmd4YsL0zygOqfdFnK7GR4QL06Do4/p7Y=
 github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
+github.com/mattn/go-sqlite3 v1.9.0 h1:pDRiWfl+++eC2FEFRy6jXmQlvp4Yh3z1MJKg4UeYM/4=
 github.com/mattn/go-sqlite3 v1.9.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/mattn/go-sqlite3 v1.11.0 h1:LDdKkqtYlom37fkvqs8rMPFKAMe8+SgjbwZ6ex1/A/Q=
 github.com/mattn/go-sqlite3 v1.11.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
@ -166,6 +172,7 @@ github.com/pborman/uuid v1.2.0 h1:J7Q5mO4ysT1dv8hyrUGHb9+ooztCXu1D8MY8DZYsu3g=
 github.com/pborman/uuid v1.2.0/go.mod h1:X/NO0urCmaxf9VXbdlT7C2Yzkj2IKimNn4k+gtPdI/k=
 github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
@ -226,6 +233,8 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 github.com/syndtr/goleveldb v0.0.0-20180815032940-ae2bd5eed72d/go.mod h1:Z4AUp2Km+PwemOoO/VB5AOx9XSsIItzFjoJlOSiYmn0=
 github.com/syndtr/goleveldb v0.0.0-20181128100959-b001fa50d6b2 h1:GnOzE5fEFN3b2zDhJJABEofdb51uMRNb8eqIVtdducs=
 github.com/syndtr/goleveldb v0.0.0-20181128100959-b001fa50d6b2/go.mod h1:Z4AUp2Km+PwemOoO/VB5AOx9XSsIItzFjoJlOSiYmn0=
+github.com/syndtr/goleveldb v1.0.0 h1:fBdIW9lB4Iz0n9khmH8w27SJ3QEJ7+IgjPEwGSZiFdE=
+github.com/syndtr/goleveldb v1.0.0/go.mod h1:ZVVdQEZoIme9iO1Ch2Jdy24qqXrMMOU6lpPAyBWyWuQ=
 github.com/tyler-smith/go-bip39 v1.0.0/go.mod h1:sJ5fKU0s6JVwZjjcUEX2zFOnvq0ASQ2K9Zr6cf67kNs=
 github.com/tyler-smith/go-bip39 v1.0.2 h1:+t3w+KwLXO6154GNJY+qUtIxLTmFjfUmpguQT1OlOT8=
 github.com/tyler-smith/go-bip39 v1.0.2/go.mod h1:sJ5fKU0s6JVwZjjcUEX2zFOnvq0ASQ2K9Zr6cf67kNs=
--- a/libraries/shared/logs/extractor.go
+++ b/libraries/shared/logs/extractor.go
@ -36,13 +36,14 @@ const (
 )

 type ILogExtractor interface {
-	AddTransformerConfig(config transformer.EventTransformerConfig)
+	AddTransformerConfig(config transformer.EventTransformerConfig) error
 	ExtractLogs(recheckHeaders constants.TransformerExecution) (error, bool)
 }

 type LogExtractor struct {
 	Addresses                []common.Address
 	CheckedHeadersRepository datastore.CheckedHeadersRepository
+	CheckedLogsRepository    datastore.CheckedLogsRepository
 	Fetcher                  fetcher.ILogFetcher
 	LogRepository            datastore.HeaderSyncLogRepository
 	StartingBlock            *int64
@ -51,7 +52,12 @@ type LogExtractor struct {
 }

 // Add additional logs to extract
-func (extractor *LogExtractor) AddTransformerConfig(config transformer.EventTransformerConfig) {
+func (extractor *LogExtractor) AddTransformerConfig(config transformer.EventTransformerConfig) error {
+	checkedHeadersErr := extractor.updateCheckedHeaders(config)
+	if checkedHeadersErr != nil {
+		return checkedHeadersErr
+	}
+
 	if extractor.StartingBlock == nil {
 		extractor.StartingBlock = &config.StartingBlockNumber
 	} else if earlierStartingBlockNumber(config.StartingBlockNumber, *extractor.StartingBlock) {
@ -61,6 +67,7 @@ func (extractor *LogExtractor) AddTransformerConfig(config transformer.EventTran
 	addresses := transformer.HexStringsToAddresses(config.ContractAddresses)
 	extractor.Addresses = append(extractor.Addresses, addresses...)
 	extractor.Topics = append(extractor.Topics, common.HexToHash(config.Topic))
+	return nil
 }

 // Fetch and persist watched logs
@ -129,3 +136,21 @@ func getCheckCount(recheckHeaders constants.TransformerExecution) int64 {
 		return constants.RecheckHeaderCap
 	}
 }
+
+func (extractor *LogExtractor) updateCheckedHeaders(config transformer.EventTransformerConfig) error {
+	hasBeenChecked, hasBeenCheckedErr := extractor.CheckedLogsRepository.HaveLogsBeenChecked(config.ContractAddresses, config.Topic)
+	if hasBeenCheckedErr != nil {
+		return hasBeenCheckedErr
+	}
+	if !hasBeenChecked {
+		err := extractor.CheckedHeadersRepository.MarkHeadersUnchecked(config.StartingBlockNumber)
+		if err != nil {
+			return err
+		}
+		nextErr := extractor.CheckedLogsRepository.MarkLogsChecked(config.ContractAddresses, config.Topic)
+		if nextErr != nil {
+			return nextErr
+		}
+	}
+	return nil
+}
--- a/libraries/shared/logs/extractor_test.go
+++ b/libraries/shared/logs/extractor_test.go
@ -31,42 +31,52 @@ import (
 )

 var _ = Describe("Log extractor", func() {
-	var extractor *logs.LogExtractor
+	var (
+		checkedHeadersRepository *fakes.MockCheckedHeadersRepository
+		checkedLogsRepository    *fakes.MockCheckedLogsRepository
+		extractor                *logs.LogExtractor
+	)

 	BeforeEach(func() {
+		checkedHeadersRepository = &fakes.MockCheckedHeadersRepository{}
+		checkedLogsRepository = &fakes.MockCheckedLogsRepository{}
 		extractor = &logs.LogExtractor{
+			CheckedHeadersRepository: checkedHeadersRepository,
+			CheckedLogsRepository:    checkedLogsRepository,
 			Fetcher:                  &mocks.MockLogFetcher{},
-			CheckedHeadersRepository: &fakes.MockCheckedHeadersRepository{},
 			LogRepository:            &fakes.MockHeaderSyncLogRepository{},
 			Syncer:                   &fakes.MockTransactionSyncer{},
 		}
 	})

 	Describe("AddTransformerConfig", func() {
-		It("it includes earliest starting block number in fetch logs query", func() {
+		It("updates extractor's starting block number to earliest available", func() {
 			earlierStartingBlockNumber := rand.Int63()
 			laterStartingBlockNumber := earlierStartingBlockNumber + 1

-			extractor.AddTransformerConfig(getTransformerConfig(laterStartingBlockNumber))
-			extractor.AddTransformerConfig(getTransformerConfig(earlierStartingBlockNumber))
+			errOne := extractor.AddTransformerConfig(getTransformerConfig(laterStartingBlockNumber))
+			Expect(errOne).NotTo(HaveOccurred())
+			errTwo := extractor.AddTransformerConfig(getTransformerConfig(earlierStartingBlockNumber))
+			Expect(errTwo).NotTo(HaveOccurred())

 			Expect(*extractor.StartingBlock).To(Equal(earlierStartingBlockNumber))
 		})

-		It("includes added addresses in fetch logs query", func() {
+		It("adds transformer's addresses to extractor's watched addresses", func() {
 			addresses := []string{"0xA", "0xB"}
 			configWithAddresses := transformer.EventTransformerConfig{
 				ContractAddresses:   addresses,
 				StartingBlockNumber: rand.Int63(),
 			}

-			extractor.AddTransformerConfig(configWithAddresses)
+			err := extractor.AddTransformerConfig(configWithAddresses)

+			Expect(err).NotTo(HaveOccurred())
 			expectedAddresses := transformer.HexStringsToAddresses(addresses)
 			Expect(extractor.Addresses).To(Equal(expectedAddresses))
 		})

-		It("includes added topics in fetch logs query", func() {
+		It("adds transformer's topic to extractor's watched topics", func() {
 			topic := "0x1"
 			configWithTopic := transformer.EventTransformerConfig{
 				ContractAddresses:   []string{fakes.FakeAddress.Hex()},
@ -74,10 +84,75 @@ var _ = Describe("Log extractor", func() {
 				StartingBlockNumber: rand.Int63(),
 			}

-			extractor.AddTransformerConfig(configWithTopic)
+			err := extractor.AddTransformerConfig(configWithTopic)

+			Expect(err).NotTo(HaveOccurred())
 			Expect(extractor.Topics).To(Equal([]common.Hash{common.HexToHash(topic)}))
 		})
+
+		It("returns error if checking whether log has been checked returns error", func() {
+			checkedLogsRepository.HasLogBeenCheckedError = fakes.FakeError
+
+			err := extractor.AddTransformerConfig(getTransformerConfig(rand.Int63()))
+
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(MatchError(fakes.FakeError))
+		})
+
+		Describe("when log has previously been checked", func() {
+			It("does not mark any headers unchecked", func() {
+				checkedLogsRepository.HasLogBeenCheckedReturn = true
+
+				err := extractor.AddTransformerConfig(getTransformerConfig(rand.Int63()))
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(checkedHeadersRepository.MarkHeadersUncheckedCalled).To(BeFalse())
+			})
+		})
+
+		Describe("when log has not previously been checked", func() {
+			BeforeEach(func() {
+				checkedLogsRepository.HasLogBeenCheckedReturn = false
+			})
+
+			It("marks headers since transformer's starting block number as unchecked", func() {
+				blockNumber := rand.Int63()
+
+				err := extractor.AddTransformerConfig(getTransformerConfig(blockNumber))
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(checkedHeadersRepository.MarkHeadersUncheckedCalled).To(BeTrue())
+				Expect(checkedHeadersRepository.MarkHeadersUncheckedStartingBlockNumber).To(Equal(blockNumber))
+			})
+
+			It("returns error if marking headers unchecked returns error", func() {
+				checkedHeadersRepository.MarkHeadersUncheckedReturnError = fakes.FakeError
+
+				err := extractor.AddTransformerConfig(getTransformerConfig(rand.Int63()))
+
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(MatchError(fakes.FakeError))
+			})
+
+			It("persists that tranformer's log has been checked", func() {
+				config := getTransformerConfig(rand.Int63())
+
+				err := extractor.AddTransformerConfig(config)
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(checkedLogsRepository.MarkLogCheckedAddresses).To(Equal(config.ContractAddresses))
+				Expect(checkedLogsRepository.MarkLogCheckedTopicZero).To(Equal(config.Topic))
+			})
+
+			It("returns error if marking logs checked returns error", func() {
+				checkedLogsRepository.MarkLogCheckedError = fakes.FakeError
+
+				err := extractor.AddTransformerConfig(getTransformerConfig(rand.Int63()))
+
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(MatchError(fakes.FakeError))
+			})
+		})
 	})

 	Describe("ExtractLogs", func() {
@ -91,7 +166,7 @@ var _ = Describe("Log extractor", func() {
 		Describe("when checking missing headers", func() {
 			It("gets missing headers since configured starting block with check_count < 1", func() {
 				mockCheckedHeadersRepository := &fakes.MockCheckedHeadersRepository{}
-				mockCheckedHeadersRepository.ReturnHeaders = []core.Header{{}}
+				mockCheckedHeadersRepository.MissingHeadersReturnHeaders = []core.Header{{}}
 				extractor.CheckedHeadersRepository = mockCheckedHeadersRepository
 				startingBlockNumber := rand.Int63()
 				extractor.AddTransformerConfig(getTransformerConfig(startingBlockNumber))
@ -99,16 +174,16 @@ var _ = Describe("Log extractor", func() {
 				err, _ := extractor.ExtractLogs(constants.HeaderMissing)

 				Expect(err).NotTo(HaveOccurred())
-				Expect(mockCheckedHeadersRepository.StartingBlockNumber).To(Equal(startingBlockNumber))
-				Expect(mockCheckedHeadersRepository.EndingBlockNumber).To(Equal(int64(-1)))
-				Expect(mockCheckedHeadersRepository.CheckCount).To(Equal(int64(1)))
+				Expect(mockCheckedHeadersRepository.MissingHeadersStartingBlockNumber).To(Equal(startingBlockNumber))
+				Expect(mockCheckedHeadersRepository.MissingHeadersEndingBlockNumber).To(Equal(int64(-1)))
+				Expect(mockCheckedHeadersRepository.MissingHeadersCheckCount).To(Equal(int64(1)))
 			})
 		})

 		Describe("when rechecking headers", func() {
 			It("gets missing headers since configured starting block with check_count < RecheckHeaderCap", func() {
 				mockCheckedHeadersRepository := &fakes.MockCheckedHeadersRepository{}
-				mockCheckedHeadersRepository.ReturnHeaders = []core.Header{{}}
+				mockCheckedHeadersRepository.MissingHeadersReturnHeaders = []core.Header{{}}
 				extractor.CheckedHeadersRepository = mockCheckedHeadersRepository
 				startingBlockNumber := rand.Int63()
 				extractor.AddTransformerConfig(getTransformerConfig(startingBlockNumber))
@ -116,9 +191,9 @@ var _ = Describe("Log extractor", func() {
 				err, _ := extractor.ExtractLogs(constants.HeaderRecheck)

 				Expect(err).NotTo(HaveOccurred())
-				Expect(mockCheckedHeadersRepository.StartingBlockNumber).To(Equal(startingBlockNumber))
-				Expect(mockCheckedHeadersRepository.EndingBlockNumber).To(Equal(int64(-1)))
-				Expect(mockCheckedHeadersRepository.CheckCount).To(Equal(constants.RecheckHeaderCap))
+				Expect(mockCheckedHeadersRepository.MissingHeadersStartingBlockNumber).To(Equal(startingBlockNumber))
+				Expect(mockCheckedHeadersRepository.MissingHeadersEndingBlockNumber).To(Equal(int64(-1)))
+				Expect(mockCheckedHeadersRepository.MissingHeadersCheckCount).To(Equal(constants.RecheckHeaderCap))
 			})
 		})

@ -274,20 +349,20 @@ var _ = Describe("Log extractor", func() {
 				addTransformerConfig(extractor)
 				mockCheckedHeadersRepository := &fakes.MockCheckedHeadersRepository{}
 				headerID := rand.Int63()
-				mockCheckedHeadersRepository.ReturnHeaders = []core.Header{{Id: headerID}}
+				mockCheckedHeadersRepository.MissingHeadersReturnHeaders = []core.Header{{Id: headerID}}
 				extractor.CheckedHeadersRepository = mockCheckedHeadersRepository

 				err, _ := extractor.ExtractLogs(constants.HeaderMissing)

 				Expect(err).NotTo(HaveOccurred())
-				Expect(mockCheckedHeadersRepository.HeaderID).To(Equal(headerID))
+				Expect(mockCheckedHeadersRepository.MarkHeaderCheckedHeaderID).To(Equal(headerID))
 			})

 			It("returns error if marking header checked fails", func() {
 				addFetchedLog(extractor)
 				addTransformerConfig(extractor)
 				mockCheckedHeadersRepository := &fakes.MockCheckedHeadersRepository{}
-				mockCheckedHeadersRepository.ReturnHeaders = []core.Header{{Id: rand.Int63()}}
+				mockCheckedHeadersRepository.MissingHeadersReturnHeaders = []core.Header{{Id: rand.Int63()}}
 				mockCheckedHeadersRepository.MarkHeaderCheckedReturnError = fakes.FakeError
 				extractor.CheckedHeadersRepository = mockCheckedHeadersRepository

@ -321,7 +396,7 @@ func addTransformerConfig(extractor *logs.LogExtractor) {

 func addMissingHeader(extractor *logs.LogExtractor) {
 	mockCheckedHeadersRepository := &fakes.MockCheckedHeadersRepository{}
-	mockCheckedHeadersRepository.ReturnHeaders = []core.Header{{}}
+	mockCheckedHeadersRepository.MissingHeadersReturnHeaders = []core.Header{{}}
 	extractor.CheckedHeadersRepository = mockCheckedHeadersRepository
 }

--- a/libraries/shared/mocks/log_extractor.go
+++ b/libraries/shared/mocks/log_extractor.go
@ -22,14 +22,16 @@ import (
 )

 type MockLogExtractor struct {
-	AddedConfigs        []transformer.EventTransformerConfig
-	ExtractLogsCount    int
-	ExtractLogsErrors   []error
-	MissingHeadersExist []bool
+	AddedConfigs              []transformer.EventTransformerConfig
+	AddTransformerConfigError error
+	ExtractLogsCount          int
+	ExtractLogsErrors         []error
+	MissingHeadersExist       []bool
 }

-func (extractor *MockLogExtractor) AddTransformerConfig(config transformer.EventTransformerConfig) {
+func (extractor *MockLogExtractor) AddTransformerConfig(config transformer.EventTransformerConfig) error {
 	extractor.AddedConfigs = append(extractor.AddedConfigs, config)
+	return extractor.AddTransformerConfigError
 }

 func (extractor *MockLogExtractor) ExtractLogs(recheckHeaders constants.TransformerExecution) (error, bool) {
--- a/libraries/shared/watcher/event_watcher.go
+++ b/libraries/shared/watcher/event_watcher.go
@ -41,8 +41,9 @@ type EventWatcher struct {

 func NewEventWatcher(db *postgres.DB, bc core.BlockChain) EventWatcher {
 	extractor := &logs.LogExtractor{
-		Fetcher:                  fetcher.NewLogFetcher(bc),
 		CheckedHeadersRepository: repositories.NewCheckedHeadersRepository(db),
+		CheckedLogsRepository:    repositories.NewCheckedLogsRepository(db),
+		Fetcher:                  fetcher.NewLogFetcher(bc),
 		LogRepository:            repositories.NewHeaderSyncLogRepository(db),
 		Syncer:                   transactions.NewTransactionsSyncer(db, bc),
 	}
@ -59,13 +60,17 @@ func NewEventWatcher(db *postgres.DB, bc core.BlockChain) EventWatcher {
 }

 // Adds transformers to the watcher so that their logs will be extracted and delegated.
-func (watcher *EventWatcher) AddTransformers(initializers []transformer.EventTransformerInitializer) {
+func (watcher *EventWatcher) AddTransformers(initializers []transformer.EventTransformerInitializer) error {
 	for _, initializer := range initializers {
 		t := initializer(watcher.db)

 		watcher.LogDelegator.AddTransformer(t)
-		watcher.LogExtractor.AddTransformerConfig(t.GetConfig())
+		err := watcher.LogExtractor.AddTransformerConfig(t.GetConfig())
+		if err != nil {
+			return err
+		}
 	}
+	return nil
 }

 // Extracts and delegates watched log events.
--- a/pkg/datastore/postgres/repositories/checked_headers_repository.go
+++ b/pkg/datastore/postgres/repositories/checked_headers_repository.go
@ -41,6 +41,12 @@ func (repo CheckedHeadersRepository) MarkHeaderChecked(headerID int64) error {
 	return err
 }

+// Remove checked_headers rows with block number >= starting block number
+func (repo CheckedHeadersRepository) MarkHeadersUnchecked(startingBlockNumber int64) error {
+	_, err := repo.db.Exec(`DELETE FROM public.checked_headers WHERE header_id IN (SELECT id FROM public.headers WHERE block_number >= $1)`, startingBlockNumber)
+	return err
+}
+
 // Return header_id if not present in checked_headers or its check_count is < passed checkCount
 func (repo CheckedHeadersRepository) MissingHeaders(startingBlockNumber, endingBlockNumber, checkCount int64) ([]core.Header, error) {
 	var result []core.Header
--- a/pkg/datastore/postgres/repositories/checked_headers_repository_test.go
+++ b/pkg/datastore/postgres/repositories/checked_headers_repository_test.go
@ -73,6 +73,47 @@ var _ = Describe("Checked Headers repository", func() {
 		})
 	})

+	Describe("MarkHeadersUnchecked", func() {
+		It("removes rows for headers <= starting block number", func() {
+			blockNumberOne := rand.Int63()
+			blockNumberTwo := blockNumberOne + 1
+			blockNumberThree := blockNumberOne + 2
+			fakeHeaderOne := fakes.GetFakeHeader(blockNumberOne)
+			fakeHeaderTwo := fakes.GetFakeHeader(blockNumberTwo)
+			fakeHeaderThree := fakes.GetFakeHeader(blockNumberThree)
+			headerRepository := repositories.NewHeaderRepository(db)
+			// insert three headers with incrementing block number
+			headerIdOne, insertHeaderOneErr := headerRepository.CreateOrUpdateHeader(fakeHeaderOne)
+			Expect(insertHeaderOneErr).NotTo(HaveOccurred())
+			headerIdTwo, insertHeaderTwoErr := headerRepository.CreateOrUpdateHeader(fakeHeaderTwo)
+			Expect(insertHeaderTwoErr).NotTo(HaveOccurred())
+			headerIdThree, insertHeaderThreeErr := headerRepository.CreateOrUpdateHeader(fakeHeaderThree)
+			Expect(insertHeaderThreeErr).NotTo(HaveOccurred())
+			// mark all headers checked
+			markHeaderOneCheckedErr := repo.MarkHeaderChecked(headerIdOne)
+			Expect(markHeaderOneCheckedErr).NotTo(HaveOccurred())
+			markHeaderTwoCheckedErr := repo.MarkHeaderChecked(headerIdTwo)
+			Expect(markHeaderTwoCheckedErr).NotTo(HaveOccurred())
+			markHeaderThreeCheckedErr := repo.MarkHeaderChecked(headerIdThree)
+			Expect(markHeaderThreeCheckedErr).NotTo(HaveOccurred())
+
+			// mark headers unchecked since blockNumberTwo
+			err := repo.MarkHeadersUnchecked(blockNumberTwo)
+
+			Expect(err).NotTo(HaveOccurred())
+			var headerOneChecked, headerTwoChecked, headerThreeChecked bool
+			getHeaderOneErr := db.Get(&headerOneChecked, `SELECT EXISTS(SELECT 1 FROM public.checked_headers WHERE header_id = $1)`, headerIdOne)
+			Expect(getHeaderOneErr).NotTo(HaveOccurred())
+			Expect(headerOneChecked).To(BeTrue())
+			getHeaderTwoErr := db.Get(&headerTwoChecked, `SELECT EXISTS(SELECT 1 FROM public.checked_headers WHERE header_id = $1)`, headerIdTwo)
+			Expect(getHeaderTwoErr).NotTo(HaveOccurred())
+			Expect(headerTwoChecked).To(BeFalse())
+			getHeaderThreeErr := db.Get(&headerThreeChecked, `SELECT EXISTS(SELECT 1 FROM public.checked_headers WHERE header_id = $1)`, headerIdThree)
+			Expect(getHeaderThreeErr).NotTo(HaveOccurred())
+			Expect(headerThreeChecked).To(BeFalse())
+		})
+	})
+
 	Describe("MissingHeaders", func() {
 		var (
 			headerRepository      datastore.HeaderRepository
--- a/pkg/datastore/postgres/repositories/checked_logs_repository.go
+++ b/pkg/datastore/postgres/repositories/checked_logs_repository.go
@ -0,0 +1,69 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program 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 Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package repositories
+
+import (
+	"github.com/sirupsen/logrus"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+)
+
+type CheckedLogsRepository struct {
+	db *postgres.DB
+}
+
+func NewCheckedLogsRepository(db *postgres.DB) CheckedLogsRepository {
+	return CheckedLogsRepository{db: db}
+}
+
+// Return whether a given address + topic0 has been fetched on a previous run of vDB
+func (repository CheckedLogsRepository) HaveLogsBeenChecked(addresses []string, topic0 string) (bool, error) {
+	for _, address := range addresses {
+		var addressExists bool
+		getAddressExistsErr := repository.db.Get(&addressExists, `SELECT EXISTS(SELECT 1 FROM public.checked_logs WHERE contract_address = $1)`, address)
+		if getAddressExistsErr != nil {
+			return false, getAddressExistsErr
+		}
+		if !addressExists {
+			return false, nil
+		}
+	}
+	var topicZeroExists bool
+	getTopicZeroExistsErr := repository.db.Get(&topicZeroExists, `SELECT EXISTS(SELECT 1 FROM public.checked_logs WHERE topic_zero = $1)`, topic0)
+	if getTopicZeroExistsErr != nil {
+		return false, getTopicZeroExistsErr
+	}
+	return topicZeroExists, nil
+}
+
+// Persist that a given address + topic0 has is being fetched on this run of vDB
+func (repository CheckedLogsRepository) MarkLogsChecked(addresses []string, topic0 string) error {
+	tx, txErr := repository.db.Beginx()
+	if txErr != nil {
+		return txErr
+	}
+	for _, address := range addresses {
+		_, insertErr := tx.Exec(`INSERT INTO public.checked_logs (contract_address, topic_zero) VALUES ($1, $2)`, address, topic0)
+		if insertErr != nil {
+			rollbackErr := tx.Rollback()
+			if rollbackErr != nil {
+				logrus.Errorf("error rolling back transaction inserting checked logs: %s", rollbackErr.Error())
+			}
+			return insertErr
+		}
+	}
+	return tx.Commit()
+}
--- a/pkg/datastore/postgres/repositories/checked_logs_repository_test.go
+++ b/pkg/datastore/postgres/repositories/checked_logs_repository_test.go
@ -0,0 +1,110 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program 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 Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package repositories_test
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres/repositories"
+	"github.com/vulcanize/vulcanizedb/pkg/fakes"
+	"github.com/vulcanize/vulcanizedb/test_config"
+)
+
+var _ = Describe("Checked logs repository", func() {
+	var (
+		db            *postgres.DB
+		fakeAddress   = fakes.FakeAddress.Hex()
+		fakeAddresses = []string{fakeAddress}
+		fakeTopicZero = fakes.FakeHash.Hex()
+		repository    datastore.CheckedLogsRepository
+	)
+
+	BeforeEach(func() {
+		db = test_config.NewTestDB(test_config.NewTestNode())
+		test_config.CleanTestDB(db)
+		repository = repositories.NewCheckedLogsRepository(db)
+	})
+
+	Describe("HaveLogsBeenChecked", func() {
+		It("returns true if all addresses and the topic0 are already present in the db", func() {
+			_, insertErr := db.Exec(`INSERT INTO public.checked_logs (contract_address, topic_zero) VALUES ($1, $2)`, fakeAddress, fakeTopicZero)
+			Expect(insertErr).NotTo(HaveOccurred())
+
+			hasBeenChecked, err := repository.HaveLogsBeenChecked(fakeAddresses, fakeTopicZero)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(hasBeenChecked).To(BeTrue())
+		})
+
+		It("returns true if addresses and topic0 were fetched because of a combination of other transformers", func() {
+			anotherFakeAddress := common.HexToAddress("0x" + fakes.RandomString(40)).Hex()
+			anotherFakeTopicZero := common.HexToHash("0x" + fakes.RandomString(64)).Hex()
+			// insert row with matching address but different topic0
+			_, insertOneErr := db.Exec(`INSERT INTO public.checked_logs (contract_address, topic_zero) VALUES ($1, $2)`, fakeAddress, anotherFakeTopicZero)
+			Expect(insertOneErr).NotTo(HaveOccurred())
+			// insert row with matching topic0 but different address
+			_, insertTwoErr := db.Exec(`INSERT INTO public.checked_logs (contract_address, topic_zero) VALUES ($1, $2)`, anotherFakeAddress, fakeTopicZero)
+			Expect(insertTwoErr).NotTo(HaveOccurred())
+
+			hasBeenChecked, err := repository.HaveLogsBeenChecked(fakeAddresses, fakeTopicZero)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(hasBeenChecked).To(BeTrue())
+		})
+
+		It("returns false if any address has not been checked", func() {
+			anotherFakeAddress := common.HexToAddress("0x" + fakes.RandomString(40)).Hex()
+			_, insertErr := db.Exec(`INSERT INTO public.checked_logs (contract_address, topic_zero) VALUES ($1, $2)`, fakeAddress, fakeTopicZero)
+			Expect(insertErr).NotTo(HaveOccurred())
+
+			hasBeenChecked, err := repository.HaveLogsBeenChecked(append(fakeAddresses, anotherFakeAddress), fakeTopicZero)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(hasBeenChecked).To(BeFalse())
+		})
+
+		It("returns false if topic0 has not been checked", func() {
+			anotherFakeTopicZero := common.HexToHash("0x" + fakes.RandomString(64)).Hex()
+			_, insertErr := db.Exec(`INSERT INTO public.checked_logs (contract_address, topic_zero) VALUES ($1, $2)`, fakeAddress, anotherFakeTopicZero)
+			Expect(insertErr).NotTo(HaveOccurred())
+
+			hasBeenChecked, err := repository.HaveLogsBeenChecked(fakeAddresses, fakeTopicZero)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(hasBeenChecked).To(BeFalse())
+		})
+	})
+
+	Describe("MarkLogsChecked", func() {
+		It("adds a row for all of transformer's addresses + topic0", func() {
+			anotherFakeAddress := common.HexToAddress("0x" + fakes.RandomString(40)).Hex()
+			err := repository.MarkLogsChecked(append(fakeAddresses, anotherFakeAddress), fakeTopicZero)
+
+			Expect(err).NotTo(HaveOccurred())
+			var comboOneExists, comboTwoExists bool
+			getComboOneErr := db.Get(&comboOneExists, `SELECT EXISTS(SELECT 1 FROM public.checked_logs WHERE contract_address = $1 AND topic_zero = $2)`, fakeAddress, fakeTopicZero)
+			Expect(getComboOneErr).NotTo(HaveOccurred())
+			Expect(comboOneExists).To(BeTrue())
+			getComboTwoErr := db.Get(&comboTwoExists, `SELECT EXISTS(SELECT 1 FROM public.checked_logs WHERE contract_address = $1 AND topic_zero = $2)`, anotherFakeAddress, fakeTopicZero)
+			Expect(getComboTwoErr).NotTo(HaveOccurred())
+			Expect(comboTwoExists).To(BeTrue())
+		})
+	})
+})
--- a/pkg/datastore/repository.go
+++ b/pkg/datastore/repository.go
@ -36,9 +36,15 @@ type BlockRepository interface {

 type CheckedHeadersRepository interface {
 	MarkHeaderChecked(headerID int64) error
+	MarkHeadersUnchecked(startingBlockNumber int64) error
 	MissingHeaders(startingBlockNumber, endingBlockNumber, checkCount int64) ([]core.Header, error)
 }

+type CheckedLogsRepository interface {
+	HaveLogsBeenChecked(addresses []string, topic0 string) (bool, error)
+	MarkLogsChecked(addresses []string, topic0 string) error
+}
+
 type ContractRepository interface {
 	CreateContract(contract core.Contract) error
 	GetContract(contractHash string) (core.Contract, error)
--- a/pkg/fakes/checked_logs_repository.go
+++ b/pkg/fakes/checked_logs_repository.go
@ -0,0 +1,39 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program 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 Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package fakes
+
+type MockCheckedLogsRepository struct {
+	HasLogBeenCheckedAddresses []string
+	HasLogBeenCheckedError     error
+	HasLogBeenCheckedReturn    bool
+	HasLogBeenCheckedTopicZero string
+	MarkLogCheckedAddresses    []string
+	MarkLogCheckedError        error
+	MarkLogCheckedTopicZero    string
+}
+
+func (repository *MockCheckedLogsRepository) HaveLogsBeenChecked(addresses []string, topic0 string) (bool, error) {
+	repository.HasLogBeenCheckedAddresses = addresses
+	repository.HasLogBeenCheckedTopicZero = topic0
+	return repository.HasLogBeenCheckedReturn, repository.HasLogBeenCheckedError
+}
+
+func (repository *MockCheckedLogsRepository) MarkLogsChecked(addresses []string, topic0 string) error {
+	repository.MarkLogCheckedAddresses = addresses
+	repository.MarkLogCheckedTopicZero = topic0
+	return repository.MarkLogCheckedError
+}
--- a/pkg/fakes/data.go
+++ b/pkg/fakes/data.go
@ -20,16 +20,16 @@ import (
 	"bytes"
 	"encoding/json"
 	"errors"
-	"strconv"
-
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
-
 	"github.com/vulcanize/vulcanizedb/pkg/core"
+	"math/rand"
+	"strconv"
+	"time"
 )

 var (
-	FakeAddress   = common.HexToAddress("0x1234567890abcdef")
+	FakeAddress   = common.HexToAddress("0x" + RandomString(40))
 	FakeError     = errors.New("failed")
 	FakeHash      = common.BytesToHash([]byte{1, 2, 3, 4, 5})
 	fakeTimestamp = int64(111111111)
@ -103,3 +103,15 @@ func GetFakeUncle(hash, reward string) core.Uncle {
 		Timestamp: strconv.FormatInt(fakeTimestamp, 10),
 	}
 }
+
+func RandomString(length int) string {
+	var seededRand = rand.New(
+		rand.NewSource(time.Now().UnixNano()))
+	charset := "abcdef1234567890"
+	b := make([]byte, length)
+	for i := range b {
+		b[i] = charset[seededRand.Intn(len(charset))]
+	}
+
+	return string(b)
+}
--- a/pkg/fakes/mock_checked_headers_repository.go
+++ b/pkg/fakes/mock_checked_headers_repository.go
@ -21,23 +21,32 @@ import (
 )

 type MockCheckedHeadersRepository struct {
-	CheckCount                   int64
-	StartingBlockNumber          int64
-	EndingBlockNumber            int64
-	HeaderID                     int64
-	ReturnHeaders                []core.Header
-	MarkHeaderCheckedReturnError error
-	MissingHeadersReturnError    error
+	MarkHeaderCheckedHeaderID               int64
+	MarkHeaderCheckedReturnError            error
+	MarkHeadersUncheckedCalled              bool
+	MarkHeadersUncheckedReturnError         error
+	MarkHeadersUncheckedStartingBlockNumber int64
+	MissingHeadersCheckCount                int64
+	MissingHeadersEndingBlockNumber         int64
+	MissingHeadersReturnError               error
+	MissingHeadersReturnHeaders             []core.Header
+	MissingHeadersStartingBlockNumber       int64
+}
+
+func (repository *MockCheckedHeadersRepository) MarkHeadersUnchecked(startingBlockNumber int64) error {
+	repository.MarkHeadersUncheckedCalled = true
+	repository.MarkHeadersUncheckedStartingBlockNumber = startingBlockNumber
+	return repository.MarkHeadersUncheckedReturnError
 }

 func (repository *MockCheckedHeadersRepository) MarkHeaderChecked(headerID int64) error {
-	repository.HeaderID = headerID
+	repository.MarkHeaderCheckedHeaderID = headerID
 	return repository.MarkHeaderCheckedReturnError
 }

 func (repository *MockCheckedHeadersRepository) MissingHeaders(startingBlockNumber, endingBlockNumber, checkCount int64) ([]core.Header, error) {
-	repository.StartingBlockNumber = startingBlockNumber
-	repository.EndingBlockNumber = endingBlockNumber
-	repository.CheckCount = checkCount
-	return repository.ReturnHeaders, repository.MissingHeadersReturnError
+	repository.MissingHeadersStartingBlockNumber = startingBlockNumber
+	repository.MissingHeadersEndingBlockNumber = endingBlockNumber
+	repository.MissingHeadersCheckCount = checkCount
+	return repository.MissingHeadersReturnHeaders, repository.MissingHeadersReturnError
 }
--- a/test_config/test_config.go
+++ b/test_config/test_config.go
@ -106,6 +106,7 @@ func CleanTestDB(db *postgres.DB) {
 	db.MustExec("DELETE FROM addresses")
 	db.MustExec("DELETE FROM blocks")
 	db.MustExec("DELETE FROM checked_headers")
+	db.MustExec("DELETE FROM checked_logs")
 	// can't delete from eth_nodes since this function is called after the required eth_node is persisted
 	db.MustExec("DELETE FROM full_sync_logs")
 	db.MustExec("DELETE FROM full_sync_receipts")