Stats: do not persist empty stats (reducing event table size and disk IOPS) (#5554)

* stats: do not persist empty stats

* fixed license headers for stat actor and stat msg tests

@@ -51,6 +51,9 @@ public class StatsActor extends ContextAwareActor {
     }
 
     public void onStatsPersistMsg(StatsPersistMsg msg) {
+        if (msg.isEmpty()) {
+            return;
+        }
         Event event = new Event();
         event.setEntityId(msg.getEntityId());
         event.setTenantId(msg.getTenantId());

@@ -37,4 +37,9 @@ public final class StatsPersistMsg implements TbActorMsg {
     public MsgType getMsgType() {
         return MsgType.STATS_PERSIST_MSG;
     }
+
+    public boolean isEmpty() {
+        return messagesProcessed == 0 && errorsOccurred == 0;
+    }
+
 }

+/**
+ * Copyright © 2016-2021 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.actors.stats;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.thingsboard.server.actors.ActorSystemContext;
+import org.thingsboard.server.common.data.Event;
+import org.thingsboard.server.common.data.id.TenantId;
+import org.thingsboard.server.dao.event.EventService;
+import org.thingsboard.server.queue.discovery.TbServiceInfoProvider;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.BDDMockito.willReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+class StatsActorTest {
+
+    StatsActor statsActor;
+    ActorSystemContext actorSystemContext;
+    EventService eventService;
+    TbServiceInfoProvider serviceInfoProvider;
+
+    @BeforeEach
+    void setUp() {
+        actorSystemContext = mock(ActorSystemContext.class);
+
+        eventService = mock(EventService.class);
+        willReturn(eventService).given(actorSystemContext).getEventService();
+        serviceInfoProvider = mock(TbServiceInfoProvider.class);
+        willReturn(serviceInfoProvider).given(actorSystemContext).getServiceInfoProvider();
+
+        statsActor = new StatsActor(actorSystemContext);
+    }
+
+    @Test
+    void givenEmptyStatMessage_whenOnStatsPersistMsg_thenNoAction() {
+        StatsPersistMsg emptyStats = new StatsPersistMsg(0, 0, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID);
+        statsActor.onStatsPersistMsg(emptyStats);
+        verify(actorSystemContext, never()).getEventService();
+    }
+
+    @Test
+    void givenNonEmptyStatMessage_whenOnStatsPersistMsg_thenNoAction() {
+        statsActor.onStatsPersistMsg(new StatsPersistMsg(0, 1, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID));
+        verify(eventService, times(1)).save(any(Event.class));
+        statsActor.onStatsPersistMsg(new StatsPersistMsg(1, 0, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID));
+        verify(eventService, times(2)).save(any(Event.class));
+        statsActor.onStatsPersistMsg(new StatsPersistMsg(1, 1, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID));
+        verify(eventService, times(3)).save(any(Event.class));
+    }
+
+}

+/**
+ * Copyright © 2016-2021 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.actors.stats;
+
+import org.junit.jupiter.api.Test;
+import org.thingsboard.server.common.data.id.TenantId;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StatsPersistMsgTest {
+
+    @Test
+    void testIsEmpty() {
+        StatsPersistMsg emptyStats = new StatsPersistMsg(0, 0, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID);
+        assertThat(emptyStats.isEmpty()).isTrue();
+    }
+
+    @Test
+    void testNotEmpty() {
+        assertThat(new StatsPersistMsg(1, 0, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID).isEmpty()).isFalse();
+        assertThat(new StatsPersistMsg(0, 1, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID).isEmpty()).isFalse();
+        assertThat(new StatsPersistMsg(1, 1, TenantId.SYS_TENANT_ID, TenantId.SYS_TENANT_ID).isEmpty()).isFalse();
+    }
+
+}