Prevent frequent commits to the node DB in sentries (erigontech#2505)

* Prevent frequent commits to the node DB in sentries

* Commit when btree goes over limit

* iterator for SeedQuery

* Fixing test

* Fix tests

Co-authored-by: Alexey Sharp <[email protected]>

cmd/sentry/download/sentry.go

@@ -19,6 +19,7 @@ import (
 	"github.com/golang/protobuf/ptypes/empty"
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
 	grpc_recovery "github.com/grpc-ecosystem/go-grpc-middleware/recovery"
+
 	//grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
 	"github.com/holiman/uint256"
 	"github.com/ledgerwatch/erigon-lib/gointerfaces"
@@ -552,6 +553,7 @@ func Sentry(datadir string, sentryAddr string, discoveryDNS []string, cfg *p2p.C
 	sentryServer.discoveryDNS = discoveryDNS
 
 	<-ctx.Done()
+	sentryServer.Close()
 	return nil
 }
 
@@ -946,6 +948,13 @@ func (ss *SentryServerImpl) Messages(req *proto_sentry.MessagesRequest, server p
 	}
 }
 
+// Close performs cleanup operations for the sentry
+func (ss *SentryServerImpl) Close() {
+	if ss.P2pServer != nil {
+		ss.P2pServer.Stop()
+	}
+}
+
 // MessageStreams - it's safe to use this class as non-pointer
 type MessageStreams struct {
 	mu      sync.RWMutex

eth/backend.go

@@ -721,5 +721,8 @@ func (s *Ethereum) Stop() error {
 	if s.config.Miner.Enabled {
 		<-s.waitForMiningStop
 	}
+	for _, sentryServer := range s.sentryServers {
+		sentryServer.Close()
+	}
 	return nil
 }