From 900a25993fa59c98ad1f737fcfb14436543d1938 Mon Sep 17 00:00:00 2001
From: Alexander Zavorotynskiy <zavorotynskiy@pm.me>
Date: Mon, 31 Jul 2023 15:48:25 +0400
Subject: [PATCH] fix(backend): removed mini ddos of sessions with negative
 duration

---
 backend/cmd/ender/main.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/backend/cmd/ender/main.go b/backend/cmd/ender/main.go
index 5f84e0983..2cf0f50b3 100644
--- a/backend/cmd/ender/main.go
+++ b/backend/cmd/ender/main.go
@@ -94,6 +94,7 @@ func main() {
 		case <-tick:
 			failedSessionEnds := make(map[uint64]uint64)
 			duplicatedSessionEnds := make(map[uint64]uint64)
+			negativeDuration := make(map[uint64]uint64)
 
 			// Find ended sessions and send notification to other services
 			sessionEndGenerator.HandleEndedSessions(func(sessionID uint64, timestamp uint64) bool {
@@ -109,6 +110,10 @@ func main() {
 						failedSessionEnds[sessionID] = timestamp
 						return true
 					}
+					if strings.Contains(err.Error(), "is less than zero for uint64") {
+						negativeDuration[sessionID] = timestamp
+						return true
+					}
 					log.Printf("can't save sessionEnd to database, sessID: %d, err: %s", sessionID, err)
 					return false
 				}
@@ -138,6 +143,9 @@ func main() {
 			if len(duplicatedSessionEnds) > 0 {
 				log.Println("session end duplicates:", duplicatedSessionEnds)
 			}
+			if len(negativeDuration) > 0 {
+				log.Println("sessions with negative duration:", negativeDuration)
+			}
 			producer.Flush(cfg.ProducerTimeout)
 			if err := consumer.CommitBack(intervals.EVENTS_BACK_COMMIT_GAP); err != nil {
 				log.Printf("can't commit messages with offset: %s", err)