apoorvmittal10 commented on code in PR #14699:
URL: https://github.com/apache/kafka/pull/14699#discussion_r1391658586
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core/src/main/java/kafka/server/ClientMetricsManager.java:
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@@ -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:
Done.
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