Merge pull request #9641 from thingsboard/hotfix/entity-rate-limits-for-gateway

Implement cache for the entity creation request

application/src/main/java/org/thingsboard/server/service/transport/DefaultTransportApiService.java

@@ -78,6 +78,7 @@ import org.thingsboard.server.dao.device.provision.ProvisionFailedException;
 import org.thingsboard.server.dao.device.provision.ProvisionRequest;
 import org.thingsboard.server.dao.device.provision.ProvisionResponse;
 import org.thingsboard.server.dao.device.provision.ProvisionResponseStatus;
+import org.thingsboard.server.dao.exception.EntitiesLimitException;
 import org.thingsboard.server.dao.ota.OtaPackageService;
 import org.thingsboard.server.dao.queue.QueueService;
 import org.thingsboard.server.dao.relation.RelationService;
@@ -164,6 +165,7 @@ public class DefaultTransportApiService implements TransportApiService {
     public void init() {
         handlerExecutor = MoreExecutors.listeningDecorator(ThingsBoardExecutors.newWorkStealingPool(maxCoreHandlerThreads, "transport-api-service-core-handler"));
     }
+
     @PreDestroy
     public void destroy() {
         if (handlerExecutor != null) {
@@ -400,6 +402,13 @@ public class DefaultTransportApiService implements TransportApiService {
         } catch (JsonProcessingException e) {
             log.warn("[{}] Failed to lookup device by gateway id and name: [{}]", gatewayId, requestMsg.getDeviceName(), e);
             throw new RuntimeException(e);
+        } catch (EntitiesLimitException e) {
+            log.warn("[{}][{}] API limit exception: [{}]", e.getTenantId(), gatewayId, e.getMessage());
+            return TransportApiResponseMsg.newBuilder()
+                    .setGetOrCreateDeviceResponseMsg(
+                            GetOrCreateDeviceFromGatewayResponseMsg.newBuilder()
+                                    .setError(TransportProtos.TransportApiRequestErrorCode.ENTITY_LIMIT))
+                    .build();
         } finally {
             deviceCreationLock.unlock();
         }

application/src/main/resources/thingsboard.yml

@@ -583,6 +583,9 @@ cache:
   rateLimits:
     timeToLiveInMinutes: "${CACHE_SPECS_RATE_LIMITS_TTL:120}" # Rate limits cache TTL
     maxSize: "${CACHE_SPECS_RATE_LIMITS_MAX_SIZE:200000}" # 0 means the cache is disabled
+  entityLimits:
+    timeToLiveInMinutes: "${CACHE_SPECS_ENTITY_LIMITS_TTL:5}" # Entity limits cache TTL
+    maxSize: "${CACHE_SPECS_ENTITY_LIMITS_MAX_SIZE:100000}" # 0 means the cache is disabled
 
 # Spring data parameters
 spring.data.redis.repositories.enabled: false # Disable this because it is not required.
@@ -875,7 +878,7 @@ transport:
     ip_limits_enabled: "${TB_TRANSPORT_IP_RATE_LIMITS_ENABLED:false}"
     # Maximum number of connect attempts with invalid credentials
     max_wrong_credentials_per_ip: "${TB_TRANSPORT_MAX_WRONG_CREDENTIALS_PER_IP:10}"
-    # Timeout to expire block IP addresses
+    # Timeout (in milliseconds) to expire block IP addresses
     ip_block_timeout: "${TB_TRANSPORT_IP_BLOCK_TIMEOUT:60000}"
   # Local HTTP transport parameters
   http:

common/cluster-api/src/main/proto/queue.proto

@@ -255,6 +255,12 @@ message GetOrCreateDeviceFromGatewayRequestMsg {
 message GetOrCreateDeviceFromGatewayResponseMsg {
   DeviceInfoProto deviceInfo = 1;
   bytes profileBody = 2;
+  TransportApiRequestErrorCode error = 3;
+}
+
+enum TransportApiRequestErrorCode {
+  UNKNOWN_TRANSPORT_API_ERROR  = 0;
+  ENTITY_LIMIT = 1;
 }
 
 message GetEntityProfileRequestMsg {

common/data/src/main/java/org/thingsboard/server/common/data/DataConstants.java

@@ -49,6 +49,7 @@ public class DataConstants {
     public static final String MQTT_TRANSPORT_NAME = "MQTT";
     public static final String HTTP_TRANSPORT_NAME = "HTTP";
     public static final String SNMP_TRANSPORT_NAME = "SNMP";
+    public static final String MAXIMUM_NUMBER_OF_DEVICES_REACHED = "Maximum number of devices reached!";
 
 
     public static final String[] allScopes() {

common/transport/mqtt/src/main/java/org/thingsboard/server/transport/mqtt/session/AbstractGatewaySessionHandler.java

@@ -35,6 +35,7 @@ import io.netty.handler.codec.mqtt.MqttPublishMessage;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.ConcurrentReferenceHashMap;
+import org.thingsboard.server.common.data.DataConstants;
 import org.thingsboard.server.common.data.StringUtils;
 import org.thingsboard.server.common.data.id.DeviceId;
 import org.thingsboard.server.common.transport.TransportService;
@@ -215,8 +216,7 @@ public abstract class AbstractGatewaySessionHandler<T extends AbstractGatewayDev
 
             @Override
             public void onFailure(Throwable t) {
-                log.warn("[{}][{}][{}] Failed to process device connect command: [{}]", gateway.getTenantId(), gateway.getDeviceId(), sessionId, deviceName, t);
+                logDeviceCreationError(t, deviceName);
-
             }
         }, context.getExecutor());
     }
@@ -248,7 +248,8 @@ public abstract class AbstractGatewaySessionHandler<T extends AbstractGatewayDev
             return future;
         }
         try {
-            transportService.process(GetOrCreateDeviceFromGatewayRequestMsg.newBuilder()
+            transportService.process(gateway.getTenantId(),
+                    GetOrCreateDeviceFromGatewayRequestMsg.newBuilder()
                             .setDeviceName(deviceName)
                             .setDeviceType(deviceType)
                             .setGatewayIdMSB(gateway.getDeviceId().getId().getMostSignificantBits())
@@ -274,9 +275,9 @@ public abstract class AbstractGatewaySessionHandler<T extends AbstractGatewayDev
                         }
 
                         @Override
-                        public void onError(Throwable e) {
+                        public void onError(Throwable t) {
-                            log.warn("[{}][{}][{}] Failed to process device connect command at getDeviceCreationFuture: [{}]", gateway.getTenantId(), gateway.getDeviceId(), sessionId, deviceName, e);
+                            logDeviceCreationError(t, deviceName);
-                            futureToSet.setException(e);
+                            futureToSet.setException(t);
                             deviceFutures.remove(deviceName);
                         }
                     });
@@ -287,6 +288,15 @@ public abstract class AbstractGatewaySessionHandler<T extends AbstractGatewayDev
         }
     }
 
+    private void logDeviceCreationError(Throwable t, String deviceName) {
+        if (DataConstants.MAXIMUM_NUMBER_OF_DEVICES_REACHED.equals(t.getMessage())) {
+            log.info("[{}][{}][{}] Failed to process device connect command: [{}] due to [{}]", gateway.getTenantId(), gateway.getDeviceId(), sessionId, deviceName,
+                    DataConstants.MAXIMUM_NUMBER_OF_DEVICES_REACHED);
+        } else {
+            log.warn("[{}][{}][{}] Failed to process device connect command: [{}]", gateway.getTenantId(), gateway.getDeviceId(), sessionId, deviceName, t);
+        }
+    }
+
     protected abstract T newDeviceSessionCtx(GetOrCreateDeviceFromGatewayResponse msg);
 
     protected int getMsgId(MqttPublishMessage mqttMsg) {

common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/TransportService.java

@@ -98,7 +98,7 @@ public interface TransportService {
     void process(ValidateDeviceLwM2MCredentialsRequestMsg msg,
                  TransportServiceCallback<ValidateDeviceCredentialsResponse> callback);
 
-    void process(GetOrCreateDeviceFromGatewayRequestMsg msg,
+    void process(TenantId tenantId, GetOrCreateDeviceFromGatewayRequestMsg msg,
                  TransportServiceCallback<GetOrCreateDeviceFromGatewayResponse> callback);
 
     void process(ProvisionDeviceRequestMsg msg,

common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/limits/DefaultEntityLimitsCache.java

@@ -0,0 +1,74 @@
+/**
+ * Copyright © 2016-2023 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.common.transport.limits;
+
+import com.github.benmanes.caffeine.cache.Cache;
+import com.github.benmanes.caffeine.cache.Caffeine;
+import com.github.benmanes.caffeine.cache.Expiry;
+import lombok.extern.slf4j.Slf4j;
+import org.jetbrains.annotations.NotNull;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+import org.thingsboard.server.queue.util.TbTransportComponent;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.TimeUnit;
+
+@Service
+@TbTransportComponent
+@Slf4j
+public class DefaultEntityLimitsCache implements EntityLimitsCache {
+
+    private static final int DEVIATION = 10;
+    private final Cache<EntityLimitKey, Boolean> cache;
+
+    public DefaultEntityLimitsCache(@Value("${cache.entityLimits.timeToLiveInMinutes:5}") int ttl,
+                                    @Value("${cache.entityLimits.maxSize:100000}") int maxSize) {
+        // We use the 'random' expiration time to avoid peak loads.
+        long mainPart = (TimeUnit.MINUTES.toNanos(ttl) / 100) * (100 - DEVIATION);
+        long randomPart = (TimeUnit.MINUTES.toNanos(ttl) / 100) * DEVIATION;
+        cache = Caffeine.newBuilder()
+                .expireAfter(new Expiry<EntityLimitKey, Boolean>() {
+                    @Override
+                    public long expireAfterCreate(@NotNull EntityLimitKey key, @NotNull Boolean value, long currentTime) {
+                        return mainPart + (long) (randomPart * ThreadLocalRandom.current().nextDouble());
+                    }
+
+                    @Override
+                    public long expireAfterUpdate(@NotNull EntityLimitKey key, @NotNull Boolean value, long currentTime, long currentDuration) {
+                        return currentDuration;
+                    }
+
+                    @Override
+                    public long expireAfterRead(@NotNull EntityLimitKey key, @NotNull Boolean value, long currentTime, long currentDuration) {
+                        return currentDuration;
+                    }
+                })
+                .maximumSize(maxSize)
+                .build();
+    }
+
+    @Override
+    public boolean get(EntityLimitKey key) {
+        var result = cache.getIfPresent(key);
+        return result != null ? result : false;
+    }
+
+    @Override
+    public void put(EntityLimitKey key, boolean value) {
+        cache.put(key, value);
+    }
+}

common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/limits/EntityLimitKey.java

@@ -0,0 +1,27 @@
+/**
+ * Copyright © 2016-2023 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.common.transport.limits;
+
+import lombok.Data;
+import org.thingsboard.server.common.data.id.TenantId;
+
+@Data
+public class EntityLimitKey {
+
+    private final TenantId tenantId;
+    private final String deviceName;
+
+}

common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/limits/EntityLimitsCache.java

@@ -0,0 +1,24 @@
+/**
+ * Copyright © 2016-2023 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.common.transport.limits;
+
+public interface EntityLimitsCache {
+
+    boolean get(EntityLimitKey key);
+
+    void put(EntityLimitKey key, boolean value);
+
+}

common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/service/DefaultTransportService.java

@@ -76,6 +76,8 @@ import org.thingsboard.server.common.transport.TransportTenantProfileCache;
 import org.thingsboard.server.common.transport.auth.GetOrCreateDeviceFromGatewayResponse;
 import org.thingsboard.server.common.transport.auth.TransportDeviceInfo;
 import org.thingsboard.server.common.transport.auth.ValidateDeviceCredentialsResponse;
+import org.thingsboard.server.common.transport.limits.EntityLimitKey;
+import org.thingsboard.server.common.transport.limits.EntityLimitsCache;
 import org.thingsboard.server.common.transport.limits.TransportRateLimitService;
 import org.thingsboard.server.common.transport.util.JsonUtils;
 import org.thingsboard.server.gen.transport.TransportProtos;
@@ -161,6 +163,7 @@ public class DefaultTransportService implements TransportService {
     @Value("${transport.stats.enabled:false}")
     private boolean statsEnabled;
 
+
     @Autowired
     @Lazy
     private TbApiUsageReportClient apiUsageClient;
@@ -184,6 +187,8 @@ public class DefaultTransportService implements TransportService {
     private final TransportResourceCache transportResourceCache;
     private final NotificationRuleProcessor notificationRuleProcessor;
 
+    private final EntityLimitsCache entityLimitsCache;
+
     protected TbQueueRequestTemplate<TbProtoQueueMsg<TransportApiRequestMsg>, TbProtoQueueMsg<TransportApiResponseMsg>> transportApiRequestTemplate;
     protected TbQueueProducer<TbProtoQueueMsg<ToRuleEngineMsg>> ruleEngineMsgProducer;
     protected TbQueueProducer<TbProtoQueueMsg<ToCoreMsg>> tbCoreMsgProducer;
@@ -212,7 +217,8 @@ public class DefaultTransportService implements TransportService {
                                    TransportTenantProfileCache tenantProfileCache,
                                    TransportRateLimitService rateLimitService,
                                    DataDecodingEncodingService dataDecodingEncodingService, SchedulerComponent scheduler, TransportResourceCache transportResourceCache,
-                                   ApplicationEventPublisher eventPublisher, NotificationRuleProcessor notificationRuleProcessor) {
+                                   ApplicationEventPublisher eventPublisher, NotificationRuleProcessor notificationRuleProcessor,
+                                   EntityLimitsCache entityLimitsCache) {
         this.partitionService = partitionService;
         this.serviceInfoProvider = serviceInfoProvider;
         this.queueProvider = queueProvider;
@@ -227,6 +233,7 @@ public class DefaultTransportService implements TransportService {
         this.transportResourceCache = transportResourceCache;
         this.eventPublisher = eventPublisher;
         this.notificationRuleProcessor = notificationRuleProcessor;
+        this.entityLimitsCache = entityLimitsCache;
     }
 
     @PostConstruct
@@ -249,7 +256,7 @@ public class DefaultTransportService implements TransportService {
     }
 
     @AfterStartUp(order = AfterStartUp.TRANSPORT_SERVICE)
-    private void start() {
+    public void start() {
         mainConsumerExecutor.execute(() -> {
             while (!stopped) {
                 try {
@@ -473,24 +480,33 @@ public class DefaultTransportService implements TransportService {
         AsyncCallbackTemplate.withCallback(response, callback::onSuccess, callback::onError, transportCallbackExecutor);
     }
 
+
     @Override
-    public void process(TransportProtos.GetOrCreateDeviceFromGatewayRequestMsg requestMsg, TransportServiceCallback<GetOrCreateDeviceFromGatewayResponse> callback) {
+    public void process(TenantId tenantId, TransportProtos.GetOrCreateDeviceFromGatewayRequestMsg requestMsg, TransportServiceCallback<GetOrCreateDeviceFromGatewayResponse> callback) {
         TbProtoQueueMsg<TransportApiRequestMsg> protoMsg = new TbProtoQueueMsg<>(UUID.randomUUID(), TransportApiRequestMsg.newBuilder().setGetOrCreateDeviceRequestMsg(requestMsg).build());
         log.trace("Processing msg: {}", requestMsg);
-        ListenableFuture<GetOrCreateDeviceFromGatewayResponse> response = Futures.transform(transportApiRequestTemplate.send(protoMsg), tmp -> {
+        var key = new EntityLimitKey(tenantId, StringUtils.truncate(requestMsg.getDeviceName(), 256));
-            TransportProtos.GetOrCreateDeviceFromGatewayResponseMsg msg = tmp.getValue().getGetOrCreateDeviceResponseMsg();
+        if (entityLimitsCache.get(key)) {
-            GetOrCreateDeviceFromGatewayResponse.GetOrCreateDeviceFromGatewayResponseBuilder result = GetOrCreateDeviceFromGatewayResponse.builder();
+            transportCallbackExecutor.submit(() -> callback.onError(new RuntimeException(DataConstants.MAXIMUM_NUMBER_OF_DEVICES_REACHED)));
-            if (msg.hasDeviceInfo()) {
+        } else {
-                TransportDeviceInfo tdi = getTransportDeviceInfo(msg.getDeviceInfo());
+            ListenableFuture<GetOrCreateDeviceFromGatewayResponse> response = Futures.transform(transportApiRequestTemplate.send(protoMsg), tmp -> {
-                result.deviceInfo(tdi);
+                TransportProtos.GetOrCreateDeviceFromGatewayResponseMsg msg = tmp.getValue().getGetOrCreateDeviceResponseMsg();
-                ByteString profileBody = msg.getProfileBody();
+                GetOrCreateDeviceFromGatewayResponse.GetOrCreateDeviceFromGatewayResponseBuilder result = GetOrCreateDeviceFromGatewayResponse.builder();
-                if (profileBody != null && !profileBody.isEmpty()) {
+                if (msg.hasDeviceInfo()) {
-                    result.deviceProfile(deviceProfileCache.getOrCreate(tdi.getDeviceProfileId(), profileBody));
+                    TransportDeviceInfo tdi = getTransportDeviceInfo(msg.getDeviceInfo());
+                    result.deviceInfo(tdi);
+                    ByteString profileBody = msg.getProfileBody();
+                    if (!profileBody.isEmpty()) {
+                        result.deviceProfile(deviceProfileCache.getOrCreate(tdi.getDeviceProfileId(), profileBody));
+                    }
+                } else if (TransportProtos.TransportApiRequestErrorCode.ENTITY_LIMIT.equals(msg.getError())) {
+                    entityLimitsCache.put(key, true);
+                    throw new RuntimeException(DataConstants.MAXIMUM_NUMBER_OF_DEVICES_REACHED);
                 }
-            }
+                return result.build();
-            return result.build();
+            }, MoreExecutors.directExecutor());
-        }, MoreExecutors.directExecutor());
+            AsyncCallbackTemplate.withCallback(response, callback::onSuccess, callback::onError, transportCallbackExecutor);
-        AsyncCallbackTemplate.withCallback(response, callback::onSuccess, callback::onError, transportCallbackExecutor);
+        }
     }
 
     @Override

dao/src/main/java/org/thingsboard/server/dao/exception/EntitiesLimitException.java

@@ -0,0 +1,35 @@
+/**
+ * Copyright © 2016-2023 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.dao.exception;
+
+import lombok.Getter;
+import org.thingsboard.server.common.data.EntityType;
+import org.thingsboard.server.common.data.id.TenantId;
+
+public class EntitiesLimitException extends DataValidationException {
+    private static final long serialVersionUID = -9211462514373279196L;
+
+    @Getter
+    private final TenantId tenantId;
+    @Getter
+    private final EntityType entityType;
+
+    public EntitiesLimitException(TenantId tenantId, EntityType entityType) {
+        super(entityType.getNormalName() + "s limit reached");
+        this.tenantId = tenantId;
+        this.entityType = entityType;
+    }
+}

dao/src/main/java/org/thingsboard/server/dao/service/DataValidator.java

@@ -26,6 +26,7 @@ import org.thingsboard.server.common.data.id.EntityId;
 import org.thingsboard.server.common.data.id.TenantId;
 import org.thingsboard.server.dao.TenantEntityWithDataDao;
 import org.thingsboard.server.dao.exception.DataValidationException;
+import org.thingsboard.server.dao.exception.EntitiesLimitException;
 import org.thingsboard.server.dao.usagerecord.ApiLimitService;
 
 import java.util.HashSet;
@@ -117,7 +118,7 @@ public abstract class DataValidator<D extends BaseData<?>> {
     protected void validateNumberOfEntitiesPerTenant(TenantId tenantId,
                                                      EntityType entityType) {
         if (!apiLimitService.checkEntitiesLimit(tenantId, entityType)) {
-            throw new DataValidationException(entityType.getNormalName() + "s limit reached");
+            throw new EntitiesLimitException(tenantId, entityType);
         }
     }
 

transport/coap/src/main/resources/tb-coap-transport.yml

@@ -49,6 +49,10 @@ zk:
 cache:
   # caffeine or redis
   type: "${CACHE_TYPE:redis}"
+  # Deliberately placed outside the 'specs' group above
+  entityLimits:
+    timeToLiveInMinutes: "${CACHE_SPECS_ENTITY_LIMITS_TTL:5}" # Entity limits cache TTL
+    maxSize: "${CACHE_SPECS_ENTITY_LIMITS_MAX_SIZE:100000}" # 0 means the cache is disabled
 
 # Redis configuration parameters
 redis:

transport/http/src/main/resources/tb-http-transport.yml

@@ -79,6 +79,10 @@ zk:
 cache:
   # caffeine or redis
   type: "${CACHE_TYPE:redis}"
+  # Deliberately placed outside the 'specs' group above
+  entityLimits:
+    timeToLiveInMinutes: "${CACHE_SPECS_ENTITY_LIMITS_TTL:5}" # Entity limits cache TTL
+    maxSize: "${CACHE_SPECS_ENTITY_LIMITS_MAX_SIZE:100000}" # 0 means the cache is disabled
 
 # Redis configuration parameters
 redis:

transport/lwm2m/src/main/resources/tb-lwm2m-transport.yml

@@ -49,6 +49,10 @@ zk:
 cache:
   # caffeine or redis
   type: "${CACHE_TYPE:redis}"
+  # Deliberately placed outside the 'specs' group above
+  entityLimits:
+    timeToLiveInMinutes: "${CACHE_SPECS_ENTITY_LIMITS_TTL:5}" # Entity limits cache TTL
+    maxSize: "${CACHE_SPECS_ENTITY_LIMITS_MAX_SIZE:100000}" # 0 means the cache is disabled
 
 # Redis configuration parameters
 redis:

transport/mqtt/src/main/resources/tb-mqtt-transport.yml

@@ -49,6 +49,10 @@ zk:
 cache:
   # caffeine or redis
   type: "${CACHE_TYPE:redis}"
+  # Deliberately placed outside the 'specs' group above
+  entityLimits:
+    timeToLiveInMinutes: "${CACHE_SPECS_ENTITY_LIMITS_TTL:5}" # Entity limits cache TTL
+    maxSize: "${CACHE_SPECS_ENTITY_LIMITS_MAX_SIZE:100000}" # 0 means the cache is disabled
 
 # Redis configuration parameters
 redis:

transport/snmp/src/main/resources/tb-snmp-transport.yml

@@ -49,6 +49,10 @@ zk:
 cache:
   # caffeine or redis
   type: "${CACHE_TYPE:redis}"
+  # Deliberately placed outside the 'specs' group above
+  entityLimits:
+    timeToLiveInMinutes: "${CACHE_SPECS_ENTITY_LIMITS_TTL:5}" # Entity limits cache TTL
+    maxSize: "${CACHE_SPECS_ENTITY_LIMITS_MAX_SIZE:100000}" # 0 means the cache is disabled
 
 # Redis configuration parameters
 redis: