Add check for negative and outdated inactivity event timestamp.

application/src/main/java/org/thingsboard/server/service/state/DefaultDeviceStateService.java

@@ -297,8 +297,20 @@ public class DefaultDeviceStateService extends AbstractPartitionBasedService<Dev
         if (cleanDeviceStateIfBelongsToExternalPartition(tenantId, deviceId)) {
             return;
         }
-        log.trace("[{}] on Device Inactivity [{}]", tenantId.getId(), deviceId.getId());
+        if (lastInactivityTime < 0) {
+            log.trace("[{}][{}] On device inactivity: received negative last inactivity ts [{}]. Skipping this event.",
+                    tenantId.getId(), deviceId.getId(), lastInactivityTime);
+            return;
+        }
+        log.trace("[{}][{}] On device inactivity: processing inactivity event with ts [{}].",
+                tenantId.getId(), deviceId.getId(), lastInactivityTime);
         DeviceStateData stateData = getOrFetchDeviceStateData(deviceId);
+        long currentLastInactivityAlarmTime = stateData.getState().getLastInactivityAlarmTime();
+        if (lastInactivityTime <= currentLastInactivityAlarmTime) {
+            log.trace("[{}][{}] On device inactivity: received outdated last inactivity ts [{}]. Skipping this event. Current last inactivity ts [{}].",
+                    tenantId.getId(), deviceId.getId(), lastInactivityTime, currentLastInactivityAlarmTime);
+            return;
+        }
         reportInactivity(lastInactivityTime, deviceId, stateData);
     }
 

application/src/test/java/org/thingsboard/server/service/state/DefaultDeviceStateServiceTest.java

@@ -21,6 +21,7 @@ import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
@@ -141,6 +142,54 @@ public class DefaultDeviceStateServiceTest {
         then(telemetrySubscriptionService).shouldHaveNoInteractions();
     }
 
+    @ParameterizedTest
+    @ValueSource(longs = {Long.MIN_VALUE, -100, -1})
+    public void givenNegativeLastInactivityTime_whenOnDeviceInactivity_thenSkipsThisEvent(long negativeLastInactivityTime) {
+        // GIVEN
+        doReturn(false).when(service).cleanDeviceStateIfBelongsToExternalPartition(tenantId, deviceId);
+
+        // WHEN
+        service.onDeviceInactivity(tenantId, deviceId, negativeLastInactivityTime);
+
+        // THEN
+        then(service).should(never()).getOrFetchDeviceStateData(deviceId);
+        then(clusterService).shouldHaveNoInteractions();
+        then(notificationRuleProcessor).shouldHaveNoInteractions();
+        then(telemetrySubscriptionService).shouldHaveNoInteractions();
+    }
+
+    @ParameterizedTest
+    @MethodSource
+    public void givenOutdatedLastInactivityTime_whenOnDeviceInactivity_thenSkipsThisEvent(long outdatedLastActivityTime, long currentLastActivityTime) {
+        // GIVEN
+        doReturn(false).when(service).cleanDeviceStateIfBelongsToExternalPartition(tenantId, deviceId);
+
+        var deviceStateData = DeviceStateData.builder()
+                .tenantId(tenantId)
+                .deviceId(deviceId)
+                .state(DeviceState.builder().lastInactivityAlarmTime(currentLastActivityTime).build())
+                .build();
+        service.deviceStates.put(deviceId, deviceStateData);
+
+        // WHEN
+        service.onDeviceInactivity(tenantId, deviceId, outdatedLastActivityTime);
+
+        // THEN
+        then(clusterService).shouldHaveNoInteractions();
+        then(notificationRuleProcessor).shouldHaveNoInteractions();
+        then(telemetrySubscriptionService).shouldHaveNoInteractions();
+    }
+
+    private static Stream<Arguments> givenOutdatedLastInactivityTime_whenOnDeviceInactivity_thenSkipsThisEvent() {
+        return Stream.of(
+                Arguments.of(0, 0),
+                Arguments.of(0, 100),
+                Arguments.of(50, 100),
+                Arguments.of(99, 100),
+                Arguments.of(100, 100)
+        );
+    }
+
     @Test
     public void givenDeviceBelongsToMyPartition_whenOnDeviceInactivity_thenReportsInactivity() {
         // GIVEN