apoorvmittal10 commented on code in PR #14699: URL: https://github.com/apache/kafka/pull/14699#discussion_r1398479956
########## core/src/main/java/kafka/server/ClientMetricsManager.java: ########## @@ -30,17 +69,376 @@ public class ClientMetricsManager implements Closeable { private static final Logger log = LoggerFactory.getLogger(ClientMetricsManager.class); private static final ClientMetricsManager INSTANCE = new ClientMetricsManager(); + private static final List<Byte> SUPPORTED_COMPRESSION_TYPES = Collections.unmodifiableList( + Arrays.asList(CompressionType.ZSTD.id, CompressionType.LZ4.id, CompressionType.GZIP.id, CompressionType.SNAPPY.id)); 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; + private final Time time; + + // The latest subscription version is used to determine if subscription has changed and needs + // to re-evaluate the client instance subscription id as per changed subscriptions. + private final AtomicInteger subscriptionUpdateVersion; + + private ClientMetricsManager() { + this(Time.SYSTEM); + } + + // Visible for testing + ClientMetricsManager(Time time) { + this.subscriptionMap = new ConcurrentHashMap<>(); + this.subscriptionUpdateVersion = new AtomicInteger(0); + this.clientInstanceCache = new SynchronizedCache<>(new LRUCache<>(CM_CACHE_MAX_SIZE)); + this.time = time; + } public void updateSubscription(String subscriptionName, Properties properties) { - // TODO: Implement the update logic to manage subscriptions. + // Validate the subscription properties. + ClientMetricsConfigs.validate(subscriptionName, properties); + // 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); + this.subscriptionUpdateVersion.incrementAndGet(); + } + return; + } + + updateClientSubscription(subscriptionName, new ClientMetricsConfigs(properties)); + } + + public GetTelemetrySubscriptionsResponse processGetTelemetrySubscriptionRequest( + GetTelemetrySubscriptionsRequest request, int telemetryMaxBytes, RequestContext requestContext, int throttleMs) { + + long now = time.milliseconds(); + 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 issues another 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 = clientInstance(clientInstanceId, requestContext); + + try { + // Validate the get request parameters for the client instance. + validateGetRequest(request, clientInstance, now); + } catch (ApiException exception) { + return request.getErrorResponse(throttleMs, exception); + } + + 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 || Uuid.RESERVED.contains(clientInstanceId)) { + String msg = String.format("Invalid request from the client [%s], invalid client instance id", + clientInstanceId); + return request.getErrorResponse(throttleMs, new InvalidRequestException(msg)); + } + + long now = time.milliseconds(); + ClientMetricsInstance clientInstance = clientInstance(clientInstanceId, requestContext); + + try { + // Validate the push request parameters for the client instance. + validatePushRequest(request, telemetryMaxBytes, clientInstance, now); + } catch (ApiException exception) { + log.debug("Error validating push telemetry request from client [{}]", clientInstanceId, 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()); + } + + // Push the metrics to the external client receiver plugin. + byte[] metrics = request.data().metrics(); + if (metrics != null && metrics.length > 0) { + try { + ClientMetricsReceiverPlugin.instance().exportMetrics(requestContext, request); + } catch (Exception exception) { + clientInstance.lastKnownError(Errors.INVALID_RECORD); + return request.errorResponse(throttleMs, Errors.INVALID_RECORD); + } + } + + clientInstance.lastKnownError(Errors.NONE); + return new PushTelemetryResponse(new PushTelemetryResponseData().setThrottleTimeMs(throttleMs)); } @Override public void close() throws IOException { - // TODO: Implement the close logic to close the client metrics manager. + subscriptionMap.clear(); + } + + 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); + + /* + 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. + */ + int version = this.subscriptionUpdateVersion.incrementAndGet(); + SubscriptionInfo newSubscription = + new SubscriptionInfo(subscriptionName, metrics, pushInterval, + ClientMetricsConfigs.parseMatchingPatterns(clientMatchPattern), version); + + subscriptionMap.put(subscriptionName, newSubscription); + } + + private Uuid generateNewClientId() { + Uuid id = Uuid.randomUuid(); + while (clientInstanceCache.get(id) != null) { + id = Uuid.randomUuid(); + } + return id; + } + + private ClientMetricsInstance clientInstance(Uuid clientInstanceId, RequestContext requestContext) { + 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. + Though cache is synchronized, but it is possible that concurrent calls can create the same + client instance. Hence, safeguard the client instance creation with a double-checked lock + to ensure that only one instance is created. + */ + synchronized (this) { + clientInstance = clientInstanceCache.get(clientInstanceId); + if (clientInstance != null) { + return clientInstance; + } + + ClientMetricsInstanceMetadata instanceMetadata = new ClientMetricsInstanceMetadata( + clientInstanceId, requestContext); + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, instanceMetadata); + } + } else if (clientInstance.subscriptionVersion() < subscriptionUpdateVersion.get()) { + /* + If the last subscription update version for client instance is older than the subscription + updated version, 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. + Though cache is synchronized, but it is possible that concurrent calls can create the same + client instance. Hence, safeguard the client instance update with a double-checked lock + to ensure that only one instance is created. + */ + synchronized (this) { + clientInstance = clientInstanceCache.get(clientInstanceId); + if (clientInstance.subscriptionVersion() >= subscriptionUpdateVersion.get()) { + return clientInstance; + } + clientInstance = createClientInstanceAndUpdateCache(clientInstanceId, clientInstance.instanceMetadata()); + } + } + + return clientInstance; + } + + private ClientMetricsInstance createClientInstanceAndUpdateCache(Uuid clientInstanceId, + ClientMetricsInstanceMetadata instanceMetadata) { + + ClientMetricsInstance clientInstance = createClientInstance(clientInstanceId, instanceMetadata); + clientInstanceCache.put(clientInstanceId, clientInstance); + return clientInstance; + } + + private ClientMetricsInstance createClientInstance(Uuid clientInstanceId, ClientMetricsInstanceMetadata instanceMetadata) { + + 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; + + int currentSubscriptionVersion = 0; + for (SubscriptionInfo info : subscriptionMap.values()) { + 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()); + currentSubscriptionVersion = Math.max(currentSubscriptionVersion, info.version()); Review Comment: My bad, I have used the global `subscriptionUpdateVersion` -- This is an automated message from the Apache Git Service. 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