diff --git a/modules/agent/common/helper.go b/modules/agent/common/helper.go
index 7e2775be..48b12429 100644
--- a/modules/agent/common/helper.go
+++ b/modules/agent/common/helper.go
@@ -373,6 +373,9 @@ func GetLatestOnlineAgentIDs(agentIds []string, lastSeconds int) (map[string]str
 			},
 		},
 	}
+	if len(agentIds) == 0 {
+		queryDSL["size"] = 2000
+	}
 	q.RawQuery = util.MustToJSONBytes(queryDSL)
 	err, result := orm.Search(event.Event{}, &q)
 	if err != nil {
diff --git a/modules/agent/state/state.go b/modules/agent/state/state.go
index f6d982f8..b833f956 100644
--- a/modules/agent/state/state.go
+++ b/modules/agent/state/state.go
@@ -109,7 +109,9 @@ func (sm *StateManager) checkAgentStatus() {
 					return
 				}
 				// status change to online
+				sm.agentMutex.Lock()
 				sm.agentIds[agentID] = model.StatusOnline
+				sm.agentMutex.Unlock()
 				log.Infof("status of agent [%s] changed to online", agentID)
 				return
 			}else{
@@ -119,7 +121,9 @@ func (sm *StateManager) checkAgentStatus() {
 				}
 			}
 			// status change to offline
+			sm.agentMutex.Lock()
 			sm.agentIds[agentID] = model.StatusOffline
+			sm.agentMutex.Unlock()
 			ag, err := sm.GetAgent(agentID)
 			if err != nil {
 				if err != elastic.ErrNotFound {