fix: filter ping timeout and retry in case of failure (#1166)

waku/v2/api/filter.go

@@ -14,7 +14,6 @@ import (
 	"go.uber.org/zap"
 )
 
-const FilterPingTimeout = 5 * time.Second
 const MultiplexChannelBuffer = 100
 
 type FilterConfig struct {

waku/v2/protocol/filter/filter_health_check.go

@@ -8,6 +8,8 @@ import (
 	"go.uber.org/zap"
 )
 
+const PingTimeout = 5 * time.Second
+
 func (wf *WakuFilterLightNode) PingPeers() {
 	//Send a ping to all the peers and report their status to corresponding subscriptions
 	// Alive or not or set state of subcription??
@@ -17,17 +19,23 @@ func (wf *WakuFilterLightNode) PingPeers() {
 }
 
 func (wf *WakuFilterLightNode) PingPeer(peer peer.ID) {
-	ctxWithTimeout, cancel := context.WithTimeout(wf.CommonService.Context(), wf.peerPingInterval)
+	ctxWithTimeout, cancel := context.WithTimeout(wf.CommonService.Context(), PingTimeout)
 	defer cancel()
 	err := wf.Ping(ctxWithTimeout, peer)
 	if err != nil {
 		wf.log.Warn("Filter ping failed towards peer", zap.Stringer("peer", peer), zap.Error(err))
-
-		subscriptions := wf.subscriptions.GetAllSubscriptionsForPeer(peer)
-		for _, subscription := range subscriptions {
-			wf.log.Debug("Notifying sub closing", zap.String("subID", subscription.ID))
-			//Indicating that subscription is closing,
-			subscription.SetClosing()
+		//quickly retry ping again before marking subscription as failure
+		//Note that PingTimeout is a fraction of PingInterval so this shouldn't cause parallel pings being sent.
+		ctxWithTimeout, cancel := context.WithTimeout(wf.CommonService.Context(), PingTimeout)
+		defer cancel()
+		err = wf.Ping(ctxWithTimeout, peer)
+		if err != nil {
+			subscriptions := wf.subscriptions.GetAllSubscriptionsForPeer(peer)
+			for _, subscription := range subscriptions {
+				wf.log.Debug("Notifying sub closing", zap.String("subID", subscription.ID))
+				//Indicating that subscription is closing,
+				subscription.SetClosing()
+			}
 		}
 	}
 }
@@ -39,7 +47,9 @@ func (wf *WakuFilterLightNode) FilterHealthCheckLoop() {
 	for {
 		select {
 		case <-ticker.C:
-			wf.PingPeers()
+			if wf.onlineChecker.IsOnline() {
+				wf.PingPeers()
+			}
 		case <-wf.CommonService.Context().Done():
 			return
 		}