From 1349aacc1d990a031b3db8b9544a25a348bea8b4 Mon Sep 17 00:00:00 2001
From: nisdas <nishdas93@gmail.com>
Date: Thu, 28 Apr 2022 18:08:12 +0800
Subject: [PATCH] cleanup discarded connections

---
 beacon-chain/powchain/rpc_connection.go | 12 ++++++++++++
 beacon-chain/powchain/service.go        |  9 +++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/beacon-chain/powchain/rpc_connection.go b/beacon-chain/powchain/rpc_connection.go
index 2918fe73e9a2..be739951be7d 100644
--- a/beacon-chain/powchain/rpc_connection.go
+++ b/beacon-chain/powchain/rpc_connection.go
@@ -62,11 +62,17 @@ func (s *Service) pollConnectionStatus(ctx context.Context) {
 		select {
 		case <-ticker.C:
 			log.Debugf("Trying to dial endpoint: %s", logs.MaskCredentialsLogging(s.cfg.currHttpEndpoint.Url))
+			currClient := s.rpcClient
 			if err := s.setupExecutionClientConnections(ctx, s.cfg.currHttpEndpoint); err != nil {
 				errorLogger(err, "Could not connect to execution client endpoint")
 				s.runError = err
 				s.fallbackToNextEndpoint()
+				continue
 			}
+			// Close previous client, if connection was successful.
+			currClient.Close()
+			log.Infof("Connected to new endpoint: %s", logs.MaskCredentialsLogging(s.cfg.currHttpEndpoint.Url))
+			return
 		case <-s.ctx.Done():
 			log.Debug("Received cancelled context,closing existing powchain service")
 			return
@@ -80,10 +86,13 @@ func (s *Service) retryExecutionClientConnection(ctx context.Context, err error)
 	s.updateConnectedETH1(false)
 	// Back off for a while before redialing.
 	time.Sleep(backOffPeriod)
+	currClient := s.rpcClient
 	if err := s.setupExecutionClientConnections(ctx, s.cfg.currHttpEndpoint); err != nil {
 		s.runError = err
 		return
 	}
+	// Close previous client, if connection was successful.
+	currClient.Close()
 	// Reset run error in the event of a successful connection.
 	s.runError = nil
 }
@@ -99,10 +108,13 @@ func (s *Service) checkDefaultEndpoint(ctx context.Context) {
 		return
 	}
 
+	currClient := s.rpcClient
 	if err := s.setupExecutionClientConnections(ctx, primaryEndpoint); err != nil {
 		log.Debugf("Primary endpoint not ready: %v", err)
 		return
 	}
+	// Close previous client, if connection was successful.
+	currClient.Close()
 	s.updateCurrHttpEndpoint(primaryEndpoint)
 }
 
diff --git a/beacon-chain/powchain/service.go b/beacon-chain/powchain/service.go
index 56129103bdb2..42b8c2f5aaf4 100644
--- a/beacon-chain/powchain/service.go
+++ b/beacon-chain/powchain/service.go
@@ -247,7 +247,7 @@ func (s *Service) Start() {
 	s.isRunning = true
 
 	// Poll the execution client connection and fallback if errors occur.
-	go s.pollConnectionStatus(s.ctx)
+	s.pollConnectionStatus(s.ctx)
 
 	// Check transition configuration for the engine API client in the background.
 	go s.checkTransitionConfiguration(s.ctx, make(chan *feed.Event, 1))
@@ -356,6 +356,7 @@ func (s *Service) ETH1ConnectionErrors() []error {
 	for _, ep := range s.cfg.httpEndpoints {
 		client, err := s.newRPCClientWithAuth(s.ctx, ep)
 		if err != nil {
+			client.Close()
 			errs = append(errs, err)
 			continue
 		}
@@ -607,7 +608,9 @@ func (s *Service) initPOWService() {
 				}
 				s.chainStartData.GenesisBlock = genBlock
 				if err := s.savePowchainData(ctx); err != nil {
+					s.retryExecutionClientConnection(ctx, err)
 					errorLogger(err, "Unable to save execution client data")
+					continue
 				}
 			}
 			return
@@ -629,17 +632,19 @@ func (s *Service) run(done <-chan struct{}) {
 		case <-done:
 			s.isRunning = false
 			s.runError = nil
+			s.rpcClient.Close()
 			s.updateConnectedETH1(false)
 			log.Debug("Context closed, exiting goroutine")
 			return
 		case <-s.headTicker.C:
 			head, err := s.eth1DataFetcher.HeaderByNumber(s.ctx, nil)
 			if err != nil {
+				s.pollConnectionStatus(s.ctx)
 				log.WithError(err).Debug("Could not fetch latest eth1 header")
 				continue
 			}
 			if eth1HeadIsBehind(head.Time) {
-				s.retryExecutionClientConnection(s.ctx, err)
+				s.pollConnectionStatus(s.ctx)
 				log.WithError(errFarBehind).Debug("Could not get an up to date eth1 header")
 				continue
 			}