Performance Improvement on start

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

@@ -135,6 +135,8 @@ public class DefaultDeviceStateService implements DeviceStateService {
     @Getter
     private int initFetchPackSize;
 
+    private volatile boolean clusterUpdatePending = false;
+
     private ListeningScheduledExecutorService queueExecutor;
     private ConcurrentMap<TenantId, Set<DeviceId>> tenantDevices = new ConcurrentHashMap<>();
     private ConcurrentMap<DeviceId, DeviceStateData> deviceStates = new ConcurrentHashMap<>();
@@ -192,7 +194,10 @@ public class DefaultDeviceStateService implements DeviceStateService {
 
     @Override
     public void onClusterUpdate() {
-        queueExecutor.submit(this::onClusterUpdateSync);
+        if (!clusterUpdatePending) {
+            clusterUpdatePending = true;
+            queueExecutor.submit(this::onClusterUpdateSync);
+        }
     }
 
     @Override
@@ -220,6 +225,7 @@ public class DefaultDeviceStateService implements DeviceStateService {
     }
 
     private void onClusterUpdateSync() {
+        clusterUpdatePending = false;
         List<Tenant> tenants = tenantService.findTenants(new TextPageLink(Integer.MAX_VALUE)).getData();
         for (Tenant tenant : tenants) {
             List<ListenableFuture<DeviceStateData>> fetchFutures = new ArrayList<>();