fix: fix bug in evm-indexer

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/armon/go-metrics v0.4.1
 	github.com/btcsuite/btcd v0.23.4
 	github.com/btcsuite/btcd/btcutil v1.1.3
+	github.com/cenkalti/backoff/v4 v4.1.3
 	github.com/cometbft/cometbft v0.37.4
 	github.com/cometbft/cometbft-db v0.9.1
 	github.com/cosmos/cosmos-proto v1.0.0-beta.4
@@ -69,7 +70,6 @@ require (
 	github.com/bgentry/speakeasy v0.1.1-0.20220910012023-760eaf8b6816 // indirect
 	github.com/btcsuite/btcd/btcec/v2 v2.3.2 // indirect
 	github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 // indirect
-	github.com/cenkalti/backoff/v4 v4.1.3 // indirect
 	github.com/cespare/xxhash v1.1.0 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/chzyer/readline v1.5.1 // indirect

server/indexer_service.go

@@ -17,8 +17,10 @@ package server
 
 import (
 	"context"
+	"errors"
 	"time"
 
+	"github.com/cenkalti/backoff/v4"
 	"github.com/cometbft/cometbft/libs/service"
 	rpcclient "github.com/cometbft/cometbft/rpc/client"
 	"github.com/cometbft/cometbft/types"
@@ -54,6 +56,14 @@ func NewEVMIndexerService(
 // and indexing them by events.
 func (eis *EVMIndexerService) OnStart() error {
 	ctx := context.Background()
+
+	// when kava in state-sync mode, it returns zero as latest_block_height, which leads to undesired behaviour, more
+	// details here: https://kava-labs.atlassian.net/wiki/spaces/ENG/pages/1623687169/EVM-Indexer+State+Sync+Issue
+	// to prevent this we wait until state-sync will finish
+	if err := waitUntilClientReady(ctx, eis.client, backoff.NewConstantBackOff(time.Second)); err != nil {
+		return err
+	}
+
 	status, err := eis.client.Status(ctx)
 	if err != nil {
 		return err
@@ -122,3 +132,24 @@ func (eis *EVMIndexerService) OnStart() error {
 		}
 	}
 }
+
+// waitUntilClientReady waits until StatusClient is ready to serve requests
+func waitUntilClientReady(ctx context.Context, client rpcclient.StatusClient, b backoff.BackOff) error {
+	err := backoff.Retry(func() error {
+		status, err := client.Status(ctx)
+		if err != nil {
+			return err
+		}
+
+		if status.SyncInfo.LatestBlockHeight == 0 {
+			return errors.New("node isn't ready, possibly in state sync process")
+		}
+
+		return nil
+	}, b)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

server/indexer_service_test.go

@@ -0,0 +1,75 @@
+package server
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/cenkalti/backoff/v4"
+	"github.com/stretchr/testify/require"
+
+	coretypes "github.com/cometbft/cometbft/rpc/core/types"
+)
+
+var (
+	failedResponse = &coretypes.ResultStatus{
+		SyncInfo: coretypes.SyncInfo{
+			LatestBlockHeight: 0,
+		},
+	}
+
+	successfulResponse = &coretypes.ResultStatus{
+		SyncInfo: coretypes.SyncInfo{
+			LatestBlockHeight: 1,
+		},
+	}
+)
+
+type statusClientMock struct {
+	// retries left before success response
+	retriesLeft uint
+}
+
+func newStatusClientMock(retriesLeft uint) *statusClientMock {
+	return &statusClientMock{
+		retriesLeft: retriesLeft,
+	}
+}
+
+func (m *statusClientMock) Status(context.Context) (*coretypes.ResultStatus, error) {
+	if m.retriesLeft == 0 {
+		return successfulResponse, nil
+	}
+
+	m.retriesLeft--
+	return failedResponse, nil
+}
+
+func TestWaitUntilClientReady(t *testing.T) {
+	for _, tc := range []struct {
+		desc        string
+		retriesLeft uint
+	}{
+		{
+			desc:        "test case #1",
+			retriesLeft: 0,
+		},
+		{
+			desc:        "test case #2",
+			retriesLeft: 1,
+		},
+		{
+			desc:        "test case #3",
+			retriesLeft: 10,
+		},
+	} {
+		t.Run(tc.desc, func(t *testing.T) {
+			ctxb := context.Background()
+			mock := newStatusClientMock(tc.retriesLeft)
+
+			err := waitUntilClientReady(ctxb, mock, backoff.NewConstantBackOff(time.Nanosecond))
+			require.NoError(t, err)
+			require.Equal(t, uint(0), mock.retriesLeft)
+		})
+	}
+}