refactor: use exponential-back-off instead of constant-back-off

server/indexer_service.go

@@ -59,7 +59,11 @@ func (eis *EVMIndexerService) OnStart() error {
 
 	// when kava in state-sync mode, it returns zero as latest_block_height, which leads to undesired behavior, more
 	// details here: https://github.com/Kava-Labs/ethermint/issues/79 to prevent this we wait until state-sync will finish
-	if err := waitUntilClientReady(ctx, eis.client, backoff.NewConstantBackOff(time.Second)); err != nil {
+	exponentialBackOff := backoff.NewExponentialBackOff(
+		backoff.WithMaxInterval(time.Second*10), // set max retry interval
+		backoff.WithMaxElapsedTime(time.Hour*3), // set timeout
+	)
+	if err := waitUntilClientReady(ctx, eis.client, exponentialBackOff); err != nil {
 		return err
 	}
 

server/indexer_service_test.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"context"
+	"math"
 	"testing"
 	"time"
 
@@ -73,3 +74,20 @@ func TestWaitUntilClientReady(t *testing.T) {
 		})
 	}
 }
+
+func TestWaitUntilClientReadyTimeout(t *testing.T) {
+	ctxb := context.Background()
+	// create a mock client which always returns an error
+	mock := newStatusClientMock(math.MaxUint)
+
+	exponentialBackOff := backoff.NewExponentialBackOff(
+		backoff.WithInitialInterval(time.Millisecond),
+		backoff.WithMaxInterval(time.Millisecond*10),
+		backoff.WithMaxElapsedTime(time.Millisecond*100),
+	)
+
+	err := waitUntilClientReady(ctxb, mock, exponentialBackOff)
+	// make sure error is propagated in case of timeout
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "node isn't ready, possibly in state sync process")
+}