junrao commented on code in PR #14699: URL: https://github.com/apache/kafka/pull/14699#discussion_r1387273811
########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -16,12 +16,48 @@ */ package kafka.server; +import java.util.Collections; Review Comment: Should this class be in the same package as other client metric related classes like `DefaultClientTelemetryPayload`? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); + clientInstance.lastPushRequestEpoch(now); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + ClientMetricsReceiverPlugin.exportMetrics(requestContext, request); + } + + clientInstance.lastKnownError(Errors.NONE); + return request.createResponse(throttleMs, Errors.NONE); } @Override public void close() throws IOException { - // TODO: Implement the close logic to close the client metrics manager. + // Do nothing for now. + } + + private void updateLastSubscriptionUpdateEpoch() { + this.lastSubscriptionUpdateEpoch = System.currentTimeMillis(); + } + + private void updateClientSubscription(String subscriptionName, ClientMetricsConfigs configs) { + List<String> metrics = configs.getList(ClientMetricsConfigs.SUBSCRIPTION_METRICS); + int pushInterval = configs.getInt(ClientMetricsConfigs.PUSH_INTERVAL_MS); + List<String> clientMatchPattern = configs.getList(ClientMetricsConfigs.CLIENT_MATCH_PATTERN); + + SubscriptionInfo newSubscription = + new SubscriptionInfo(subscriptionName, metrics, pushInterval, + ClientMetricsConfigs.parseMatchingPatterns(clientMatchPattern)); + + subscriptionMap.put(subscriptionName, newSubscription); + } + + private Uuid generateNewClientId() { + Uuid id = Uuid.randomUuid(); + while (clientInstanceCache.get(id) != null) { + id = Uuid.randomUuid(); + } + return id; + } + + private ClientMetricsInstance getClientInstance(Uuid clientInstanceId, RequestContext requestContext, + long timestamp) { + // Check if null can be called on the cache. if can then we can avoid the method call. + ClientMetricsInstance clientInstance = clientInstanceCache.get(clientInstanceId); + + if (clientInstance == null) { + // If the client instance is not present in the cache, then create a new client instance + // and update the cache. This can also happen when the telemetry request is received by + // the separate broker instance. + ClientMetricsInstanceMetadata instanceMetadata = new ClientMetricsInstanceMetadata( + clientInstanceId, requestContext); + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, instanceMetadata, timestamp); + } else if (clientInstance.subscriptionUpdateEpoch() < lastSubscriptionUpdateEpoch) { + /* + If the last subscription update time for client instance is older than the subscription + updated time, then re-evaluate the subscription information for the client as per the + updated subscriptions. This is to ensure that the client instance is always in sync with + the latest subscription information. + */ + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, clientInstance.instanceMetadata(), timestamp); + } + + return clientInstance; + } + + private ClientMetricsInstance createClientInstanceAndUpdateCache(Uuid clientInstanceId, + ClientMetricsInstanceMetadata instanceMetadata, long timestamp) { + + ClientMetricsInstance clientInstance = createClientInstance(clientInstanceId, instanceMetadata, + timestamp); + clientInstanceCache.put(clientInstanceId, clientInstance); + return clientInstance; + } + + private ClientMetricsInstance createClientInstance(Uuid clientInstanceId, + ClientMetricsInstanceMetadata instanceMetadata, long timestamp) { + + int pushIntervalMs = ClientMetricsConfigs.DEFAULT_INTERVAL_MS; + // Keep a set of metrics to avoid duplicates in case of overlapping subscriptions. + Set<String> subscribedMetrics = new HashSet<>(); + boolean allMetricsSubscribed = false; + + for (SubscriptionInfo info : subscriptions()) { + if (instanceMetadata.isMatch(info.matchPattern())) { + allMetricsSubscribed = allMetricsSubscribed || info.metrics().contains( Review Comment: We don't need to include `allMetricsSubscribed` since it's false at this point? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); + clientInstance.lastPushRequestEpoch(now); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + ClientMetricsReceiverPlugin.exportMetrics(requestContext, request); Review Comment: Should we catch any exception and convert that to an `INVALID_RECORD` in the response? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); + clientInstance.lastPushRequestEpoch(now); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + ClientMetricsReceiverPlugin.exportMetrics(requestContext, request); + } + + clientInstance.lastKnownError(Errors.NONE); + return request.createResponse(throttleMs, Errors.NONE); } @Override public void close() throws IOException { - // TODO: Implement the close logic to close the client metrics manager. + // Do nothing for now. Review Comment: Should we clear up the internal data? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); + clientInstance.lastPushRequestEpoch(now); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + ClientMetricsReceiverPlugin.exportMetrics(requestContext, request); + } + + clientInstance.lastKnownError(Errors.NONE); + return request.createResponse(throttleMs, Errors.NONE); } @Override public void close() throws IOException { - // TODO: Implement the close logic to close the client metrics manager. + // Do nothing for now. + } + + private void updateLastSubscriptionUpdateEpoch() { + this.lastSubscriptionUpdateEpoch = System.currentTimeMillis(); + } + + private void updateClientSubscription(String subscriptionName, ClientMetricsConfigs configs) { + List<String> metrics = configs.getList(ClientMetricsConfigs.SUBSCRIPTION_METRICS); + int pushInterval = configs.getInt(ClientMetricsConfigs.PUSH_INTERVAL_MS); + List<String> clientMatchPattern = configs.getList(ClientMetricsConfigs.CLIENT_MATCH_PATTERN); + + SubscriptionInfo newSubscription = + new SubscriptionInfo(subscriptionName, metrics, pushInterval, + ClientMetricsConfigs.parseMatchingPatterns(clientMatchPattern)); + + subscriptionMap.put(subscriptionName, newSubscription); + } + + private Uuid generateNewClientId() { + Uuid id = Uuid.randomUuid(); + while (clientInstanceCache.get(id) != null) { + id = Uuid.randomUuid(); + } + return id; + } + + private ClientMetricsInstance getClientInstance(Uuid clientInstanceId, RequestContext requestContext, + long timestamp) { + // Check if null can be called on the cache. if can then we can avoid the method call. + ClientMetricsInstance clientInstance = clientInstanceCache.get(clientInstanceId); + + if (clientInstance == null) { + // If the client instance is not present in the cache, then create a new client instance + // and update the cache. This can also happen when the telemetry request is received by + // the separate broker instance. + ClientMetricsInstanceMetadata instanceMetadata = new ClientMetricsInstanceMetadata( + clientInstanceId, requestContext); + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, instanceMetadata, timestamp); + } else if (clientInstance.subscriptionUpdateEpoch() < lastSubscriptionUpdateEpoch) { Review Comment: Hmm, a subscription could be updated again in the same millisec. Is this check sufficient? ########## core/src/main/java/kafka/metrics/ClientMetricsInstance.java: ########## @@ -0,0 +1,121 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 kafka.metrics; + +import org.apache.kafka.common.Uuid; +import org.apache.kafka.common.protocol.Errors; + +import java.util.Objects; +import java.util.Set; + +/** + * Contains the metrics instance metadata and the state of the client instance. + */ +public class ClientMetricsInstance { + + private final Uuid clientInstanceId; + private final ClientMetricsInstanceMetadata instanceMetadata; + private final int subscriptionId; + private final long subscriptionUpdateEpoch; + private final Set<String> metrics; + private final int pushIntervalMs; + + private boolean terminating; + private long lastGetRequestEpoch; + private long lastPushRequestEpoch; + private Errors lastKnownError; Review Comment: Does this need to be volatile since it's written and read by different threads. Ditto for other fields like `terminating` ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; Review Comment: Should this be volatile since it's written and read by different threads? ########## clients/src/main/java/org/apache/kafka/common/requests/PushTelemetryRequest.java: ########## @@ -71,6 +73,31 @@ public PushTelemetryRequestData data() { return data; } + public PushTelemetryResponse createResponse(int throttleTimeMs, Errors errors) { + PushTelemetryResponseData responseData = new PushTelemetryResponseData(); + responseData.setErrorCode(errors.code()); + responseData.setThrottleTimeMs(throttleTimeMs); + return new PushTelemetryResponse(responseData); + } + + public String getMetricsContentType() { Review Comment: We don't use getters. So this can just be `metricsContentType`. Ditto for `getMetricsData`. ########## core/src/main/java/kafka/metrics/ClientMetricsReceiverPlugin.java: ########## @@ -0,0 +1,52 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 kafka.metrics; + +import org.apache.kafka.common.requests.PushTelemetryRequest; +import org.apache.kafka.common.requests.RequestContext; +import org.apache.kafka.server.telemetry.ClientTelemetryReceiver; + +import java.util.ArrayList; +import java.util.List; + +/** + * Plugin to register client telemetry receivers and export metrics. This class is used by the Kafka + * server to export client metrics to the registered receivers. + */ +public class ClientMetricsReceiverPlugin { + + private static final List<ClientTelemetryReceiver> RECEIVERS = new ArrayList<>(); Review Comment: Could we make the field and the method instance level instead of static? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); Review Comment: The KIP didn't talk about this. But if the client is hard killed, should we expire the client instance on the broker after some time? ########## clients/src/main/java/org/apache/kafka/common/requests/PushTelemetryRequest.java: ########## @@ -71,6 +73,31 @@ public PushTelemetryRequestData data() { return data; } + public PushTelemetryResponse createResponse(int throttleTimeMs, Errors errors) { + PushTelemetryResponseData responseData = new PushTelemetryResponseData(); + responseData.setErrorCode(errors.code()); + responseData.setThrottleTimeMs(throttleTimeMs); Review Comment: If error code is not `ThrottlingQuotaExceededException`, we should ignore `throttleTimeMs`. Could we redirect `getErrorResponse` to here and rename it to `errorResponse`? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); + clientInstance.lastPushRequestEpoch(now); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + ClientMetricsReceiverPlugin.exportMetrics(requestContext, request); + } + + clientInstance.lastKnownError(Errors.NONE); + return request.createResponse(throttleMs, Errors.NONE); } @Override public void close() throws IOException { - // TODO: Implement the close logic to close the client metrics manager. + // Do nothing for now. + } + + private void updateLastSubscriptionUpdateEpoch() { + this.lastSubscriptionUpdateEpoch = System.currentTimeMillis(); + } + + private void updateClientSubscription(String subscriptionName, ClientMetricsConfigs configs) { + List<String> metrics = configs.getList(ClientMetricsConfigs.SUBSCRIPTION_METRICS); + int pushInterval = configs.getInt(ClientMetricsConfigs.PUSH_INTERVAL_MS); + List<String> clientMatchPattern = configs.getList(ClientMetricsConfigs.CLIENT_MATCH_PATTERN); + + SubscriptionInfo newSubscription = + new SubscriptionInfo(subscriptionName, metrics, pushInterval, + ClientMetricsConfigs.parseMatchingPatterns(clientMatchPattern)); + + subscriptionMap.put(subscriptionName, newSubscription); + } + + private Uuid generateNewClientId() { + Uuid id = Uuid.randomUuid(); + while (clientInstanceCache.get(id) != null) { + id = Uuid.randomUuid(); + } + return id; + } + + private ClientMetricsInstance getClientInstance(Uuid clientInstanceId, RequestContext requestContext, + long timestamp) { + // Check if null can be called on the cache. if can then we can avoid the method call. + ClientMetricsInstance clientInstance = clientInstanceCache.get(clientInstanceId); + + if (clientInstance == null) { + // If the client instance is not present in the cache, then create a new client instance + // and update the cache. This can also happen when the telemetry request is received by + // the separate broker instance. + ClientMetricsInstanceMetadata instanceMetadata = new ClientMetricsInstanceMetadata( + clientInstanceId, requestContext); + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, instanceMetadata, timestamp); + } else if (clientInstance.subscriptionUpdateEpoch() < lastSubscriptionUpdateEpoch) { + /* + If the last subscription update time for client instance is older than the subscription + updated time, then re-evaluate the subscription information for the client as per the + updated subscriptions. This is to ensure that the client instance is always in sync with + the latest subscription information. + */ + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, clientInstance.instanceMetadata(), timestamp); + } + + return clientInstance; + } + + private ClientMetricsInstance createClientInstanceAndUpdateCache(Uuid clientInstanceId, + ClientMetricsInstanceMetadata instanceMetadata, long timestamp) { + + ClientMetricsInstance clientInstance = createClientInstance(clientInstanceId, instanceMetadata, + timestamp); + clientInstanceCache.put(clientInstanceId, clientInstance); + return clientInstance; + } + + private ClientMetricsInstance createClientInstance(Uuid clientInstanceId, + ClientMetricsInstanceMetadata instanceMetadata, long timestamp) { + + int pushIntervalMs = ClientMetricsConfigs.DEFAULT_INTERVAL_MS; + // Keep a set of metrics to avoid duplicates in case of overlapping subscriptions. + Set<String> subscribedMetrics = new HashSet<>(); + boolean allMetricsSubscribed = false; + + for (SubscriptionInfo info : subscriptions()) { + if (instanceMetadata.isMatch(info.matchPattern())) { + allMetricsSubscribed = allMetricsSubscribed || info.metrics().contains( + ClientMetricsConfigs.ALL_SUBSCRIBED_METRICS_CONFIG); + subscribedMetrics.addAll(info.metrics()); + pushIntervalMs = Math.min(pushIntervalMs, info.intervalMs()); + } + } + + /* + If client matches with any subscription that has empty metrics string, then it means that client + is subscribed to all the metrics, so just send the empty string as the subscribed metrics. + */ + if (allMetricsSubscribed) { + subscribedMetrics.clear(); + // Add an empty string to indicate that all metrics are subscribed. + subscribedMetrics.add(ClientMetricsConfigs.ALL_SUBSCRIBED_METRICS); + } + + int subscriptionId = computeSubscriptionId(subscribedMetrics, pushIntervalMs, clientInstanceId); + + return new ClientMetricsInstance(clientInstanceId, instanceMetadata, subscriptionId, timestamp, + subscribedMetrics, pushIntervalMs); + } + + /** + * Computes the SubscriptionId as a unique identifier for a client instance's subscription set, + * the id is generated by calculating a CRC32 of the configured metrics subscriptions including + * the PushIntervalMs, XORed with the ClientInstanceId. + */ + private int computeSubscriptionId(Set<String> metrics, int pushIntervalMs, Uuid clientInstanceId) { + CRC32 crc = new CRC32(); + byte[] metricsBytes = (metrics.toString() + pushIntervalMs).getBytes(StandardCharsets.UTF_8); + crc.update(ByteBuffer.wrap(metricsBytes)); + return (int) crc.getValue() ^ clientInstanceId.hashCode(); + } + + private GetTelemetrySubscriptionsResponse createGetSubscriptionResponse(Uuid clientInstanceId, + ClientMetricsInstance clientInstance, int telemetryMaxBytes, int throttleMs) { + + GetTelemetrySubscriptionsResponseData data = new GetTelemetrySubscriptionsResponseData() + .setClientInstanceId(clientInstanceId) + .setSubscriptionId(clientInstance.subscriptionId()) + .setRequestedMetrics(new ArrayList<>(clientInstance.metrics())) + .setAcceptedCompressionTypes(getSupportedCompressionTypes()) + .setPushIntervalMs(clientInstance.pushIntervalMs()) + .setTelemetryMaxBytes(telemetryMaxBytes) + .setDeltaTemporality(true) + .setErrorCode(Errors.NONE.code()) + .setThrottleTimeMs(throttleMs); + + return new GetTelemetrySubscriptionsResponse(data); + } + + private void validateGetRequest(GetTelemetrySubscriptionsRequest request, + ClientMetricsInstance clientInstance) { + + if (!clientInstance.canAcceptGetRequest() && clientInstance.lastKnownError() != Errors.UNKNOWN_SUBSCRIPTION_ID) { + String msg = String.format("Request from the client [%s] arrived before the next push interval time", + request.data().clientInstanceId()); + throw new ThrottlingQuotaExceededException(msg); + } + } + + private void validatePushRequest(PushTelemetryRequest request, int telemetryMaxBytes, + ClientMetricsInstance clientInstance) { + + if (clientInstance.terminating()) { + String msg = String.format( + "Client [%s] sent the previous request with state terminating to TRUE, can not accept" + + "any requests after that", request.data().clientInstanceId()); + throw new InvalidRequestException(msg); + } + + if (!clientInstance.canAcceptPushRequest() && !request.data().terminating()) { + String msg = String.format("Request from the client [%s] arrived before the next push interval time", + request.data().clientInstanceId()); + throw new ThrottlingQuotaExceededException(msg); + } + + if (request.data().subscriptionId() != clientInstance.subscriptionId()) { + String msg = String.format("Unknown client subscription id for the client [%s]", + request.data().clientInstanceId()); + throw new UnknownSubscriptionIdException(msg); + } + + if (!isSupportedCompressionType(request.data().compressionType())) { + String msg = String.format("Unknown compression type [%s] is received in telemetry request from [%s]", + request.data().compressionType(), request.data().clientInstanceId()); + throw new UnsupportedCompressionTypeException(msg); + } + + if (request.data().metrics() != null && request.data().metrics().length > telemetryMaxBytes) { + String msg = String.format("Telemetry request from [%s] is larger than the maximum allowed size [%s]", + request.data().clientInstanceId(), telemetryMaxBytes); + throw new TelemetryTooLargeException(msg); + } + } + + private List<Byte> getSupportedCompressionTypes() { + List<Byte> compressionTypes = new ArrayList<>(); + for (CompressionType compressionType : CompressionType.values()) { Review Comment: Are we returning the compression type in the preferred order? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); + clientInstance.lastPushRequestEpoch(now); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + ClientMetricsReceiverPlugin.exportMetrics(requestContext, request); + } + + clientInstance.lastKnownError(Errors.NONE); + return request.createResponse(throttleMs, Errors.NONE); } @Override public void close() throws IOException { - // TODO: Implement the close logic to close the client metrics manager. + // Do nothing for now. + } + + private void updateLastSubscriptionUpdateEpoch() { + this.lastSubscriptionUpdateEpoch = System.currentTimeMillis(); + } + + private void updateClientSubscription(String subscriptionName, ClientMetricsConfigs configs) { + List<String> metrics = configs.getList(ClientMetricsConfigs.SUBSCRIPTION_METRICS); + int pushInterval = configs.getInt(ClientMetricsConfigs.PUSH_INTERVAL_MS); + List<String> clientMatchPattern = configs.getList(ClientMetricsConfigs.CLIENT_MATCH_PATTERN); + + SubscriptionInfo newSubscription = + new SubscriptionInfo(subscriptionName, metrics, pushInterval, + ClientMetricsConfigs.parseMatchingPatterns(clientMatchPattern)); + + subscriptionMap.put(subscriptionName, newSubscription); + } + + private Uuid generateNewClientId() { + Uuid id = Uuid.randomUuid(); + while (clientInstanceCache.get(id) != null) { + id = Uuid.randomUuid(); + } + return id; + } + + private ClientMetricsInstance getClientInstance(Uuid clientInstanceId, RequestContext requestContext, + long timestamp) { + // Check if null can be called on the cache. if can then we can avoid the method call. + ClientMetricsInstance clientInstance = clientInstanceCache.get(clientInstanceId); + + if (clientInstance == null) { + // If the client instance is not present in the cache, then create a new client instance + // and update the cache. This can also happen when the telemetry request is received by + // the separate broker instance. + ClientMetricsInstanceMetadata instanceMetadata = new ClientMetricsInstanceMetadata( + clientInstanceId, requestContext); + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, instanceMetadata, timestamp); + } else if (clientInstance.subscriptionUpdateEpoch() < lastSubscriptionUpdateEpoch) { + /* + If the last subscription update time for client instance is older than the subscription + updated time, then re-evaluate the subscription information for the client as per the + updated subscriptions. This is to ensure that the client instance is always in sync with + the latest subscription information. + */ + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, clientInstance.instanceMetadata(), timestamp); + } + + return clientInstance; + } + + private ClientMetricsInstance createClientInstanceAndUpdateCache(Uuid clientInstanceId, + ClientMetricsInstanceMetadata instanceMetadata, long timestamp) { + + ClientMetricsInstance clientInstance = createClientInstance(clientInstanceId, instanceMetadata, + timestamp); + clientInstanceCache.put(clientInstanceId, clientInstance); + return clientInstance; + } + + private ClientMetricsInstance createClientInstance(Uuid clientInstanceId, + ClientMetricsInstanceMetadata instanceMetadata, long timestamp) { + + int pushIntervalMs = ClientMetricsConfigs.DEFAULT_INTERVAL_MS; + // Keep a set of metrics to avoid duplicates in case of overlapping subscriptions. + Set<String> subscribedMetrics = new HashSet<>(); + boolean allMetricsSubscribed = false; + + for (SubscriptionInfo info : subscriptions()) { + if (instanceMetadata.isMatch(info.matchPattern())) { + allMetricsSubscribed = allMetricsSubscribed || info.metrics().contains( + ClientMetricsConfigs.ALL_SUBSCRIBED_METRICS_CONFIG); + subscribedMetrics.addAll(info.metrics()); + pushIntervalMs = Math.min(pushIntervalMs, info.intervalMs()); + } + } + + /* + If client matches with any subscription that has empty metrics string, then it means that client + is subscribed to all the metrics, so just send the empty string as the subscribed metrics. + */ + if (allMetricsSubscribed) { + subscribedMetrics.clear(); + // Add an empty string to indicate that all metrics are subscribed. + subscribedMetrics.add(ClientMetricsConfigs.ALL_SUBSCRIBED_METRICS); + } + + int subscriptionId = computeSubscriptionId(subscribedMetrics, pushIntervalMs, clientInstanceId); + + return new ClientMetricsInstance(clientInstanceId, instanceMetadata, subscriptionId, timestamp, + subscribedMetrics, pushIntervalMs); + } + + /** + * Computes the SubscriptionId as a unique identifier for a client instance's subscription set, + * the id is generated by calculating a CRC32 of the configured metrics subscriptions including + * the PushIntervalMs, XORed with the ClientInstanceId. + */ + private int computeSubscriptionId(Set<String> metrics, int pushIntervalMs, Uuid clientInstanceId) { + CRC32 crc = new CRC32(); + byte[] metricsBytes = (metrics.toString() + pushIntervalMs).getBytes(StandardCharsets.UTF_8); + crc.update(ByteBuffer.wrap(metricsBytes)); + return (int) crc.getValue() ^ clientInstanceId.hashCode(); + } + + private GetTelemetrySubscriptionsResponse createGetSubscriptionResponse(Uuid clientInstanceId, + ClientMetricsInstance clientInstance, int telemetryMaxBytes, int throttleMs) { + + GetTelemetrySubscriptionsResponseData data = new GetTelemetrySubscriptionsResponseData() + .setClientInstanceId(clientInstanceId) + .setSubscriptionId(clientInstance.subscriptionId()) + .setRequestedMetrics(new ArrayList<>(clientInstance.metrics())) + .setAcceptedCompressionTypes(getSupportedCompressionTypes()) + .setPushIntervalMs(clientInstance.pushIntervalMs()) + .setTelemetryMaxBytes(telemetryMaxBytes) + .setDeltaTemporality(true) + .setErrorCode(Errors.NONE.code()) + .setThrottleTimeMs(throttleMs); + + return new GetTelemetrySubscriptionsResponse(data); + } + + private void validateGetRequest(GetTelemetrySubscriptionsRequest request, + ClientMetricsInstance clientInstance) { + + if (!clientInstance.canAcceptGetRequest() && clientInstance.lastKnownError() != Errors.UNKNOWN_SUBSCRIPTION_ID) { + String msg = String.format("Request from the client [%s] arrived before the next push interval time", + request.data().clientInstanceId()); + throw new ThrottlingQuotaExceededException(msg); + } + } + + private void validatePushRequest(PushTelemetryRequest request, int telemetryMaxBytes, + ClientMetricsInstance clientInstance) { + + if (clientInstance.terminating()) { + String msg = String.format( + "Client [%s] sent the previous request with state terminating to TRUE, can not accept" + + "any requests after that", request.data().clientInstanceId()); + throw new InvalidRequestException(msg); + } + + if (!clientInstance.canAcceptPushRequest() && !request.data().terminating()) { + String msg = String.format("Request from the client [%s] arrived before the next push interval time", + request.data().clientInstanceId()); + throw new ThrottlingQuotaExceededException(msg); + } + + if (request.data().subscriptionId() != clientInstance.subscriptionId()) { + String msg = String.format("Unknown client subscription id for the client [%s]", + request.data().clientInstanceId()); + throw new UnknownSubscriptionIdException(msg); + } + + if (!isSupportedCompressionType(request.data().compressionType())) { + String msg = String.format("Unknown compression type [%s] is received in telemetry request from [%s]", + request.data().compressionType(), request.data().clientInstanceId()); + throw new UnsupportedCompressionTypeException(msg); + } + + if (request.data().metrics() != null && request.data().metrics().length > telemetryMaxBytes) { + String msg = String.format("Telemetry request from [%s] is larger than the maximum allowed size [%s]", + request.data().clientInstanceId(), telemetryMaxBytes); + throw new TelemetryTooLargeException(msg); + } + } + + private List<Byte> getSupportedCompressionTypes() { Review Comment: This can just be `supportedCompressionTypes`. ########## core/src/main/java/kafka/metrics/ClientMetricsInstanceMetadata.java: ########## @@ -0,0 +1,72 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 kafka.metrics; + +import java.util.regex.Pattern; +import org.apache.kafka.common.Uuid; +import org.apache.kafka.common.requests.RequestContext; + +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; + +/** + * Information from the client's metadata is gathered from the client's request. + */ +public class ClientMetricsInstanceMetadata { + + private final Map<String, String> attributesMap; + + public ClientMetricsInstanceMetadata(Uuid clientInstanceId, RequestContext requestContext) { + Objects.requireNonNull(clientInstanceId); + Objects.requireNonNull(requestContext); + + attributesMap = new HashMap<>(); + + attributesMap.put(ClientMetricsConfigs.CLIENT_INSTANCE_ID, clientInstanceId.toString()); + attributesMap.put(ClientMetricsConfigs.CLIENT_ID, requestContext.clientId()); + attributesMap.put(ClientMetricsConfigs.CLIENT_SOFTWARE_NAME, requestContext.clientInformation != null ? + requestContext.clientInformation.softwareName() : null); + attributesMap.put(ClientMetricsConfigs.CLIENT_SOFTWARE_VERSION, requestContext.clientInformation != null ? + requestContext.clientInformation.softwareVersion() : null); + attributesMap.put(ClientMetricsConfigs.CLIENT_SOURCE_ADDRESS, requestContext.clientAddress != null ? + requestContext.clientAddress.getHostAddress() : null); + // KIP-714 mentions client source port should be the client connection's source port from the + // broker's point of view. But the broker does not have this information rather the port could be + // the broker's port where the client connection is established. We might want to consider removing + // the client source port from the KIP or use broker port if that can be helpful. + // TODO: fix port Review Comment: We populate `RequestContext` in `SocketServer`. We could obtain the client port through `transportLayer.socketChannel().socket().getPort` in `KafkaChannel`. ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = System.currentTimeMillis(); + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance); + } catch (ApiException exception) { + clientInstance.lastKnownError(Errors.forException(exception)); + return request.getErrorResponse(throttleMs, exception); + } finally { + // Update the client instance with the latest push request parameters. + clientInstance.terminating(request.data().terminating()); + clientInstance.lastPushRequestEpoch(now); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + ClientMetricsReceiverPlugin.exportMetrics(requestContext, request); + } + + clientInstance.lastKnownError(Errors.NONE); + return request.createResponse(throttleMs, Errors.NONE); } @Override public void close() throws IOException { - // TODO: Implement the close logic to close the client metrics manager. + // Do nothing for now. + } + + private void updateLastSubscriptionUpdateEpoch() { + this.lastSubscriptionUpdateEpoch = System.currentTimeMillis(); + } + + private void updateClientSubscription(String subscriptionName, ClientMetricsConfigs configs) { + List<String> metrics = configs.getList(ClientMetricsConfigs.SUBSCRIPTION_METRICS); + int pushInterval = configs.getInt(ClientMetricsConfigs.PUSH_INTERVAL_MS); + List<String> clientMatchPattern = configs.getList(ClientMetricsConfigs.CLIENT_MATCH_PATTERN); + + SubscriptionInfo newSubscription = + new SubscriptionInfo(subscriptionName, metrics, pushInterval, + ClientMetricsConfigs.parseMatchingPatterns(clientMatchPattern)); + + subscriptionMap.put(subscriptionName, newSubscription); + } + + private Uuid generateNewClientId() { + Uuid id = Uuid.randomUuid(); + while (clientInstanceCache.get(id) != null) { + id = Uuid.randomUuid(); + } + return id; + } + + private ClientMetricsInstance getClientInstance(Uuid clientInstanceId, RequestContext requestContext, + long timestamp) { + // Check if null can be called on the cache. if can then we can avoid the method call. Review Comment: Have you checked that yet? ########## clients/src/main/java/org/apache/kafka/common/requests/PushTelemetryRequest.java: ########## @@ -71,6 +73,31 @@ public PushTelemetryRequestData data() { return data; } + public PushTelemetryResponse createResponse(int throttleTimeMs, Errors errors) { + PushTelemetryResponseData responseData = new PushTelemetryResponseData(); + responseData.setErrorCode(errors.code()); + responseData.setThrottleTimeMs(throttleTimeMs); + return new PushTelemetryResponse(responseData); + } + + public String getMetricsContentType() { + // Future versions of PushTelemetryRequest and GetTelemetrySubscriptionsRequest may include a content-type + // field to allow for updated OTLP format versions (or additional formats), but this field is currently not + // included since only one format is specified in the current proposal of the kip-714 + return OTLP_CONTENT_TYPE; + } + + public ByteBuffer getMetricsData() { + CompressionType cType = CompressionType.forId(this.data.compressionType()); + return (cType == CompressionType.NONE) ? + ByteBuffer.wrap(this.data.metrics()) : decompressMetricsData(cType, this.data.metrics()); + } + + private static ByteBuffer decompressMetricsData(CompressionType compressionType, byte[] metrics) { + // TODO: Add support for decompression of metrics data Review Comment: So, this will be added in a future PR? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -34,13 +70,348 @@ public class ClientMetricsManager implements Closeable { public static ClientMetricsManager instance() { return INSTANCE; } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; + private final Cache<Uuid, ClientMetricsInstance> clientInstanceCache; + private final Map<String, SubscriptionInfo> subscriptionMap; + + // The last subscription updated time is used to determine if the next telemetry request needs + // to re-evaluate the subscription id as per changes subscriptions. + private long lastSubscriptionUpdateEpoch; + + // Visible for testing + ClientMetricsManager() { + subscriptionMap = new ConcurrentHashMap<>(); + clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // IncrementalAlterConfigs API will send empty configs when all the configs are deleted + // for respective subscription. In that case, we need to remove the subscription from the map. + if (properties.isEmpty()) { + // Remove the subscription from the map if it exists, else ignore the config update. + if (subscriptionMap.containsKey(subscriptionName)) { + log.info("Removing subscription [{}] from the subscription map", subscriptionName); + subscriptionMap.remove(subscriptionName); + updateLastSubscriptionUpdateEpoch(); + } + return; + } + + ClientMetricsConfigs configs = new ClientMetricsConfigs(properties); + updateClientSubscription(subscriptionName, configs); + /* + Update last subscription updated time to current time to indicate that there is a change + in the subscription. This will be used to determine if the next telemetry request needs + to re-evaluate the subscription id as per changes subscriptions. + */ + updateLastSubscriptionUpdateEpoch(); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = System.currentTimeMillis(); + Uuid clientInstanceId = Optional.ofNullable(request.data().clientInstanceId()) + .filter(id -> !id.equals(Uuid.ZERO_UUID)) + .orElse(generateNewClientId()); + + /* + Get the client instance from the cache or create a new one. If subscription has changed + since the last request, then the client instance will be re-evaluated. Validation of the + request will be done after the client instance is created. If client issued get telemetry + request prior to push interval, then the client should get a throttle error but if the + subscription has changed since the last request then the client should get the updated + subscription immediately. + */ + ClientMetricsInstance clientInstance = getClientInstance(clientInstanceId, requestContext, now); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } finally { + clientInstance.lastGetRequestEpoch(now); + } + + clientInstance.lastKnownError(Errors.NONE); + return createGetSubscriptionResponse(clientInstanceId, clientInstance, telemetryMaxBytes, throttleMs); + } + + public PushTelemetryResponse processPushTelemetryRequest(PushTelemetryRequest request, + int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + Uuid clientInstanceId = request.data().clientInstanceId(); + if (clientInstanceId == null || clientInstanceId == Uuid.ZERO_UUID) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); Review Comment: Do we need to set `throttleMs` for invalid request error? ########## core/src/main/java/kafka/metrics/ClientMetricsConfigs.java: ########## @@ -80,6 +82,11 @@ public class ClientMetricsConfigs { public static final String CLIENT_SOURCE_ADDRESS = "client_source_address"; public static final String CLIENT_SOURCE_PORT = "client_source_port"; + // Empty string in client-metrics resource configs indicates that all the metrics are subscribed. + public static final String ALL_SUBSCRIBED_METRICS_CONFIG = "\"\""; Review Comment: This is what the user provides. Why is `ALL_SUBSCRIBED_METRICS` not the same as this? ########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -0,0 +1,416 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 kafka.server; + +import java.util.Collections; +import java.util.regex.Pattern; +import kafka.metrics.ClientMetricsConfigs; +import kafka.metrics.ClientMetricsInstance; +import kafka.metrics.ClientMetricsInstanceMetadata; +import kafka.metrics.ClientMetricsReceiverPlugin; + +import org.apache.kafka.common.Uuid; +import org.apache.kafka.common.cache.Cache; +import org.apache.kafka.common.cache.LRUCache; +import org.apache.kafka.common.cache.SynchronizedCache; +import org.apache.kafka.common.errors.ApiException; +import org.apache.kafka.common.errors.InvalidRequestException; +import org.apache.kafka.common.errors.TelemetryTooLargeException; +import org.apache.kafka.common.errors.ThrottlingQuotaExceededException; +import org.apache.kafka.common.errors.UnknownSubscriptionIdException; +import org.apache.kafka.common.errors.UnsupportedCompressionTypeException; +import org.apache.kafka.common.message.GetTelemetrySubscriptionsResponseData; +import org.apache.kafka.common.protocol.Errors; +import org.apache.kafka.common.record.CompressionType; +import org.apache.kafka.common.requests.GetTelemetrySubscriptionsRequest; +import org.apache.kafka.common.requests.GetTelemetrySubscriptionsResponse; +import org.apache.kafka.common.requests.PushTelemetryRequest; +import org.apache.kafka.common.requests.PushTelemetryResponse; +import org.apache.kafka.common.requests.RequestContext; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.Closeable; +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.charset.StandardCharsets; +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Properties; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.zip.CRC32; + +/** + * Handles client telemetry metrics requests/responses, subscriptions and instance information. + */ +public class ClientMetricsManager implements Closeable { + + private static final Logger log = LoggerFactory.getLogger(ClientMetricsManager.class); + private static final ClientMetricsManager INSTANCE = new ClientMetricsManager(); + + public static ClientMetricsManager instance() { + return INSTANCE; + } + // Max cache size (16k active client connections per broker) + private static final int CM_CACHE_MAX_SIZE = 16384; Review Comment: Is this enough? A broker could handle 100s of Ks of connections. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org