chia7712 commented on a change in pull request #10275: URL: https://github.com/apache/kafka/pull/10275#discussion_r589631318
########## File path: clients/src/main/java/org/apache/kafka/clients/admin/DescribeProducersResult.java ########## @@ -0,0 +1,76 @@ +/* + * 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 org.apache.kafka.clients.admin; + +import org.apache.kafka.common.KafkaException; +import org.apache.kafka.common.KafkaFuture; +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.common.annotation.InterfaceStability; +import org.apache.kafka.common.internals.KafkaFutureImpl; + +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.concurrent.ExecutionException; + +@InterfaceStability.Evolving +public class DescribeProducersResult { + + private final Map<TopicPartition, KafkaFutureImpl<PartitionProducerState>> futures; + + DescribeProducersResult(Map<TopicPartition, KafkaFutureImpl<PartitionProducerState>> futures) { + this.futures = futures; + } + + public KafkaFuture<PartitionProducerState> partitionResult(final TopicPartition partition) { + KafkaFuture<PartitionProducerState> future = futures.get(partition); + if (future == null) { + throw new IllegalArgumentException("Topic partition " + partition + + " was not included in the request"); + } + return future; + } + + public KafkaFuture<Map<TopicPartition, PartitionProducerState>> all() { + return KafkaFuture.allOf(futures.values().toArray(new KafkaFuture[0])) + .thenApply(nil -> { + Map<TopicPartition, PartitionProducerState> results = new HashMap<>(futures.size()); + for (Map.Entry<TopicPartition, KafkaFutureImpl<PartitionProducerState>> entry : futures.entrySet()) { + try { + results.put(entry.getKey(), entry.getValue().get()); + } catch (InterruptedException | ExecutionException e) { + // This should be unreachable, because allOf ensured that all the futures completed successfully. + throw new KafkaException(e); + } + } + return results; + }); + } + + public static class PartitionProducerState { + private final List<ProducerState> activeProducers; + + public PartitionProducerState(List<ProducerState> activeProducers) { Review comment: Could we change the modifier from public to package-private? Exposing this constructor to users is useless. ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/DescribeProducersOptions.java ########## @@ -0,0 +1,63 @@ +/* + * 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 org.apache.kafka.clients.admin; + +import org.apache.kafka.common.annotation.InterfaceStability; + +import java.util.Collection; +import java.util.Objects; +import java.util.OptionalInt; + +/** + * Options for {@link Admin#describeProducers(Collection)}. + * + * The API of this class is evolving, see {@link Admin} for details. + */ +@InterfaceStability.Evolving +public class DescribeProducersOptions extends AbstractOptions<DescribeProducersOptions> { Review comment: Could we make it override `timeoutMs` in order to write following code. ```java new DescribeProducersOptions() .timeoutMs(11) .setBrokerId(1) ``` ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/DescribeProducersOptions.java ########## @@ -0,0 +1,63 @@ +/* + * 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 org.apache.kafka.clients.admin; + +import org.apache.kafka.common.annotation.InterfaceStability; + +import java.util.Collection; +import java.util.Objects; +import java.util.OptionalInt; + +/** + * Options for {@link Admin#describeProducers(Collection)}. + * + * The API of this class is evolving, see {@link Admin} for details. + */ +@InterfaceStability.Evolving +public class DescribeProducersOptions extends AbstractOptions<DescribeProducersOptions> { + private OptionalInt brokerId = OptionalInt.empty(); + + public DescribeProducersOptions setBrokerId(int brokerId) { Review comment: Other options classes does not call it `setXXX`. Maybe we should following consistent naming? ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/DescribeProducersOptions.java ########## @@ -0,0 +1,63 @@ +/* + * 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 org.apache.kafka.clients.admin; + +import org.apache.kafka.common.annotation.InterfaceStability; + +import java.util.Collection; +import java.util.Objects; +import java.util.OptionalInt; + +/** + * Options for {@link Admin#describeProducers(Collection)}. + * + * The API of this class is evolving, see {@link Admin} for details. + */ +@InterfaceStability.Evolving +public class DescribeProducersOptions extends AbstractOptions<DescribeProducersOptions> { + private OptionalInt brokerId = OptionalInt.empty(); + + public DescribeProducersOptions setBrokerId(int brokerId) { + this.brokerId = OptionalInt.of(brokerId); + return this; + } + + public OptionalInt brokerId() { + return brokerId; + } + + @Override + public boolean equals(Object o) { + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + DescribeProducersOptions that = (DescribeProducersOptions) o; + return Objects.equals(brokerId, that.brokerId); + } + + @Override + public int hashCode() { + return Objects.hash(brokerId); Review comment: include `timeoutMs`? ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/internals/AdminApiDriver.java ########## @@ -0,0 +1,464 @@ +/* + * 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 org.apache.kafka.clients.admin.internals; + +import org.apache.kafka.clients.admin.internals.AdminApiHandler.DynamicKeyMapping; +import org.apache.kafka.clients.admin.internals.AdminApiHandler.KeyMappings; +import org.apache.kafka.clients.admin.internals.AdminApiHandler.StaticKeyMapping; +import org.apache.kafka.clients.admin.internals.AdminApiLookupStrategy.RequestScope; +import org.apache.kafka.common.errors.DisconnectException; +import org.apache.kafka.common.internals.KafkaFutureImpl; +import org.apache.kafka.common.requests.AbstractRequest; +import org.apache.kafka.common.requests.AbstractResponse; +import org.apache.kafka.common.utils.LogContext; +import org.slf4j.Logger; + +import java.util.ArrayList; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Objects; +import java.util.Optional; +import java.util.OptionalInt; +import java.util.Set; +import java.util.function.BiFunction; + +/** + * The `KafkaAdminClient`'s internal `Call` primitive is not a good fit for multi-stage + * request workflows such as we see with the group coordinator APIs or any request which + * needs to be sent to a partition leader. Typically these APIs have two concrete stages: + * + * 1. Lookup: Find the broker that can fulfill the request (e.g. partition leader or group + * coordinator) + * 2. Fulfillment: Send the request to the broker found in the first step + * + * This is complicated by the fact that `Admin` APIs are typically batched, which + * means the Lookup stage may result in a set of brokers. For example, take a `ListOffsets` + * request for a set of topic partitions. In the Lookup stage, we will find the partition + * leaders for this set of partitions; in the Fulfillment stage, we will group together + * partition according to the IDs of the discovered leaders. + * + * Additionally, the flow between these two stages is bi-directional. We may find after + * sending a `ListOffsets` request to an expected leader that there was a leader change. + * This would result in a topic partition being sent back to the Lookup stage. + * + * Managing this complexity by chaining together `Call` implementations is challenging + * and messy, so instead we use this class to do the bookkeeping. It handles both the + * batching aspect as well as the transitions between the Lookup and Fulfillment stages. + * + * Note that the interpretation of the `retries` configuration becomes ambiguous + * for this kind of pipeline. We could treat it as an overall limit on the number + * of requests that can be sent, but that is not very useful because each pipeline + * has a minimum number of requests that need to be sent in order to satisfy the request. + * Instead, we treat this number of retries independently at each stage so that each + * stage has at least one opportunity to complete. So if a user sets `retries=1`, then + * the full pipeline can still complete as long as there are no request failures. + * + * @param <K> The key type, which is also the granularity of the request routing (e.g. + * this could be `TopicPartition` in the case of requests intended for a partition + * leader or the `GroupId` in the case of consumer group requests intended for + * the group coordinator) + * @param <V> The fulfillment type for each key (e.g. this could be consumer group state + * when the key type is a consumer `GroupId`) + */ +public class AdminApiDriver<K, V> { + private final Logger log; + private final long retryBackoffMs; + private final long deadlineMs; + private final AdminApiHandler<K, V> handler; + private final Optional<StaticKeyMapping<K>> staticMapping; + private final Optional<DynamicKeyMapping<K>> dynamicMapping; + private final Map<K, KafkaFutureImpl<V>> futures; + + private final BiMultimap<RequestScope, K> lookupMap = new BiMultimap<>(); + private final BiMultimap<BrokerScope, K> fulfillmentMap = new BiMultimap<>(); + private final Map<RequestScope, RequestState> requestStates = new HashMap<>(); + + + public AdminApiDriver( + AdminApiHandler<K, V> handler, + long deadlineMs, + long retryBackoffMs, + LogContext logContext + ) { + this.handler = handler; + this.deadlineMs = deadlineMs; + this.retryBackoffMs = retryBackoffMs; + this.log = logContext.logger(AdminApiDriver.class); + this.futures = new HashMap<>(); + + KeyMappings<K> result = handler.initializeKeys(); + this.dynamicMapping = result.dynamicMapping; + this.staticMapping = result.staticMapping; + + initializeKeys(); + } + + private void initializeKeys() { + staticMapping.ifPresent(mapping -> { + for (Map.Entry<K, Integer> staticMapping : mapping.keys.entrySet()) { + K key = staticMapping.getKey(); + Integer brokerId = staticMapping.getValue(); + futures.put(key, new KafkaFutureImpl<>()); + map(key, brokerId); + } + }); + + dynamicMapping.ifPresent(mapping -> { + for (K key : mapping.keys) { + futures.put(key, new KafkaFutureImpl<>()); + lookupMap.put(mapping.lookupStrategy.lookupScope(key), key); + } + }); + } + + /** + * Associate a key with a brokerId. This is called after a response in the Lookup + * stage reveals the mapping (e.g. when the `FindCoordinator` tells us the the + * group coordinator for a specific consumer group). + */ + private void map(K key, Integer brokerId) { + lookupMap.remove(key); + fulfillmentMap.put(new BrokerScope(brokerId), key); + + // To allow for derived keys, we create futures dynamically if they + // do not already exist in the future map + futures.computeIfAbsent(key, k -> new KafkaFutureImpl<>()); + } + + /** + * Disassociate a key from the currently mapped brokerId. This will send the key + * back to the Lookup stage, which will allow us to attempt lookup again. + */ + private void unmap(K key) { + DynamicKeyMapping<K> mapping = dynamicMapping.orElseThrow(() -> + new IllegalStateException("Attempt to unmap key " + key + " which is not dynamically mapped") + ); + fulfillmentMap.remove(key); + lookupMap.put(mapping.lookupStrategy.lookupScope(key), key); + } + + private void clear(K key) { + lookupMap.remove(key); + fulfillmentMap.remove(key); + } + + OptionalInt keyToBrokerId(K key) { Review comment: It seems `keyToBrokerId` (and `getKey`) are used by testing only. Is it worthwhile to keep a `reverseMap` in production code for testing? ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/internals/AdminApiDriver.java ########## @@ -0,0 +1,464 @@ +/* + * 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 org.apache.kafka.clients.admin.internals; + +import org.apache.kafka.clients.admin.internals.AdminApiHandler.DynamicKeyMapping; +import org.apache.kafka.clients.admin.internals.AdminApiHandler.KeyMappings; +import org.apache.kafka.clients.admin.internals.AdminApiHandler.StaticKeyMapping; +import org.apache.kafka.clients.admin.internals.AdminApiLookupStrategy.RequestScope; +import org.apache.kafka.common.errors.DisconnectException; +import org.apache.kafka.common.internals.KafkaFutureImpl; +import org.apache.kafka.common.requests.AbstractRequest; +import org.apache.kafka.common.requests.AbstractResponse; +import org.apache.kafka.common.utils.LogContext; +import org.slf4j.Logger; + +import java.util.ArrayList; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Objects; +import java.util.Optional; +import java.util.OptionalInt; +import java.util.Set; +import java.util.function.BiFunction; + +/** + * The `KafkaAdminClient`'s internal `Call` primitive is not a good fit for multi-stage + * request workflows such as we see with the group coordinator APIs or any request which + * needs to be sent to a partition leader. Typically these APIs have two concrete stages: + * + * 1. Lookup: Find the broker that can fulfill the request (e.g. partition leader or group + * coordinator) + * 2. Fulfillment: Send the request to the broker found in the first step + * + * This is complicated by the fact that `Admin` APIs are typically batched, which + * means the Lookup stage may result in a set of brokers. For example, take a `ListOffsets` + * request for a set of topic partitions. In the Lookup stage, we will find the partition + * leaders for this set of partitions; in the Fulfillment stage, we will group together + * partition according to the IDs of the discovered leaders. + * + * Additionally, the flow between these two stages is bi-directional. We may find after + * sending a `ListOffsets` request to an expected leader that there was a leader change. + * This would result in a topic partition being sent back to the Lookup stage. + * + * Managing this complexity by chaining together `Call` implementations is challenging + * and messy, so instead we use this class to do the bookkeeping. It handles both the + * batching aspect as well as the transitions between the Lookup and Fulfillment stages. + * + * Note that the interpretation of the `retries` configuration becomes ambiguous + * for this kind of pipeline. We could treat it as an overall limit on the number + * of requests that can be sent, but that is not very useful because each pipeline + * has a minimum number of requests that need to be sent in order to satisfy the request. + * Instead, we treat this number of retries independently at each stage so that each + * stage has at least one opportunity to complete. So if a user sets `retries=1`, then + * the full pipeline can still complete as long as there are no request failures. + * + * @param <K> The key type, which is also the granularity of the request routing (e.g. + * this could be `TopicPartition` in the case of requests intended for a partition + * leader or the `GroupId` in the case of consumer group requests intended for + * the group coordinator) + * @param <V> The fulfillment type for each key (e.g. this could be consumer group state + * when the key type is a consumer `GroupId`) + */ +public class AdminApiDriver<K, V> { + private final Logger log; + private final long retryBackoffMs; + private final long deadlineMs; + private final AdminApiHandler<K, V> handler; + private final Optional<StaticKeyMapping<K>> staticMapping; + private final Optional<DynamicKeyMapping<K>> dynamicMapping; + private final Map<K, KafkaFutureImpl<V>> futures; + + private final BiMultimap<RequestScope, K> lookupMap = new BiMultimap<>(); + private final BiMultimap<BrokerScope, K> fulfillmentMap = new BiMultimap<>(); + private final Map<RequestScope, RequestState> requestStates = new HashMap<>(); + + + public AdminApiDriver( + AdminApiHandler<K, V> handler, + long deadlineMs, + long retryBackoffMs, + LogContext logContext + ) { + this.handler = handler; + this.deadlineMs = deadlineMs; + this.retryBackoffMs = retryBackoffMs; + this.log = logContext.logger(AdminApiDriver.class); + this.futures = new HashMap<>(); + + KeyMappings<K> result = handler.initializeKeys(); + this.dynamicMapping = result.dynamicMapping; + this.staticMapping = result.staticMapping; + + initializeKeys(); + } + + private void initializeKeys() { + staticMapping.ifPresent(mapping -> { + for (Map.Entry<K, Integer> staticMapping : mapping.keys.entrySet()) { + K key = staticMapping.getKey(); + Integer brokerId = staticMapping.getValue(); + futures.put(key, new KafkaFutureImpl<>()); + map(key, brokerId); + } + }); + + dynamicMapping.ifPresent(mapping -> { + for (K key : mapping.keys) { + futures.put(key, new KafkaFutureImpl<>()); + lookupMap.put(mapping.lookupStrategy.lookupScope(key), key); + } + }); + } + + /** + * Associate a key with a brokerId. This is called after a response in the Lookup + * stage reveals the mapping (e.g. when the `FindCoordinator` tells us the the + * group coordinator for a specific consumer group). + */ + private void map(K key, Integer brokerId) { + lookupMap.remove(key); + fulfillmentMap.put(new BrokerScope(brokerId), key); + + // To allow for derived keys, we create futures dynamically if they + // do not already exist in the future map + futures.computeIfAbsent(key, k -> new KafkaFutureImpl<>()); + } + + /** + * Disassociate a key from the currently mapped brokerId. This will send the key + * back to the Lookup stage, which will allow us to attempt lookup again. + */ + private void unmap(K key) { + DynamicKeyMapping<K> mapping = dynamicMapping.orElseThrow(() -> + new IllegalStateException("Attempt to unmap key " + key + " which is not dynamically mapped") + ); + fulfillmentMap.remove(key); + lookupMap.put(mapping.lookupStrategy.lookupScope(key), key); + } + + private void clear(K key) { + lookupMap.remove(key); + fulfillmentMap.remove(key); + } + + OptionalInt keyToBrokerId(K key) { + Optional<BrokerScope> scope = fulfillmentMap.getKey(key); + if (scope.isPresent()) { + return OptionalInt.of(scope.get().destinationBrokerId); + } else { + return OptionalInt.empty(); + } + } + + /** + * Complete the future associated with the given key exceptionally. After is called, + * the key will be taken out of both the Lookup and Fulfillment stages so that request + * are not retried. + */ + private void completeExceptionally(K key, Throwable t) { + KafkaFutureImpl<V> future = futures.get(key); + if (future == null) { + log.warn("Attempt to complete future for {}, which was not requested", key); + } else { + clear(key); + future.completeExceptionally(t); + } + } + + /** + * Complete the future associated with the given key. After is called, the key will + * be taken out of both the Lookup and Fulfillment stages so that request are not retried. + */ + private void complete(K key, V value) { + KafkaFutureImpl<V> future = futures.get(key); + if (future == null) { + log.warn("Attempt to complete future for {}, which was not requested", key); + } else { + clear(key); + future.complete(value); + } + } + + /** + * Check whether any requests need to be sent. This should be called immediately + * after the driver is constructed and then again after each request returns + * (i.e. after {@link #onFailure(long, RequestSpec, Throwable)} or + * {@link #onResponse(long, RequestSpec, AbstractResponse)}). + * + * @return A list of requests that need to be sent + */ + public List<RequestSpec<K>> poll() { + List<RequestSpec<K>> requests = new ArrayList<>(); + collectLookupRequests(requests); + collectFulfillmentRequests(requests); + return requests; + } + + /** + * Get a map of the futures that are awaiting completion. + */ + public Map<K, KafkaFutureImpl<V>> futures() { + return futures; + } + + /** + * Callback that is invoked when a `Call` returns a response successfully. + */ + public void onResponse( + long currentTimeMs, + RequestSpec<K> spec, + AbstractResponse response + ) { + clearInflightRequest(currentTimeMs, spec); + if (spec.scope instanceof AdminApiDriver.BrokerScope) { + int brokerId = ((BrokerScope) spec.scope).destinationBrokerId; + AdminApiHandler.ApiResult<K, V> result = handler.handleResponse( + brokerId, + spec.keys, + response + ); + result.completedKeys.forEach(this::complete); + result.failedKeys.forEach(this::completeExceptionally); + result.unmappedKeys.forEach(this::unmap); + } else { + DynamicKeyMapping<K> mapping = dynamicMapping.orElseThrow(() -> + new IllegalStateException("Received response for unexpected dynamic lookup scope " + spec.scope) + ); + + AdminApiLookupStrategy.LookupResult<K> result = mapping.lookupStrategy.handleResponse( + spec.keys, + response + ); + result.failedKeys.forEach(this::completeExceptionally); + result.mappedKeys.forEach(this::map); + } + } + + /** + * Callback that is invoked when a `Call` is failed. + */ + public void onFailure( + long currentTimeMs, + RequestSpec<K> spec, + Throwable t + ) { + clearInflightRequest(currentTimeMs, spec); + if (t instanceof DisconnectException) { + log.debug("Node disconnected before response could be received for request {}. " + + "Will attempt retry", spec.request); + dynamicMapping.ifPresent(mapping -> { + if (mapping.keys.containsAll(spec.keys)) { + spec.keys.forEach(this::unmap); + } + }); + } else { + spec.keys.forEach(key -> completeExceptionally(key, t)); + } + } + + private void clearInflightRequest(long currentTimeMs, RequestSpec<K> spec) { + RequestState requestState = requestStates.get(spec.scope); + if (requestState != null) { + requestState.clearInflight(currentTimeMs); + } + } + + private <T extends RequestScope> void collectRequests( + List<RequestSpec<K>> requests, + BiMultimap<T, K> multimap, + BiFunction<Set<K>, T, AbstractRequest.Builder<?>> buildRequest + ) { + for (Map.Entry<T, Set<K>> entry : multimap.entrySet()) { + T scope = entry.getKey(); + + Set<K> keys = entry.getValue(); + if (keys.isEmpty()) { + continue; + } + + RequestState requestState = requestStates.computeIfAbsent(scope, c -> new RequestState()); + if (requestState.hasInflight()) { + continue; + } + + AbstractRequest.Builder<?> request = buildRequest.apply(keys, scope); + RequestSpec<K> spec = new RequestSpec<>( + handler.apiName() + "(api=" + request.apiKey() + ")", + scope, + new HashSet<>(keys), // copy to avoid exposing mutable state + request, + requestState.nextAllowedRetryMs, + deadlineMs, + requestState.tries + ); + + requestState.setInflight(spec); + requests.add(spec); + } + } + + private void collectLookupRequests(List<RequestSpec<K>> requests) { + dynamicMapping.ifPresent(mapping -> { + collectRequests( + requests, + lookupMap, + (keys, scope) -> mapping.lookupStrategy.buildRequest(keys) + ); + }); + } + + private void collectFulfillmentRequests(List<RequestSpec<K>> requests) { + collectRequests( + requests, + fulfillmentMap, + (keys, scope) -> handler.buildRequest(scope.destinationBrokerId, keys) + ); + } + + /** + * This is a helper class which helps us to map requests that need to be sent + * to the internal `Call` implementation that is used internally in + * {@link org.apache.kafka.clients.admin.KafkaAdminClient}. + */ + public static class RequestSpec<K> { + public final String name; + public final RequestScope scope; + public final Set<K> keys; + public final AbstractRequest.Builder<?> request; + public final long nextAllowedTryMs; + public final long deadlineMs; + public final int tries; + + public RequestSpec( + String name, + RequestScope scope, + Set<K> keys, + AbstractRequest.Builder<?> request, + long nextAllowedTryMs, + long deadlineMs, + int tries + ) { + this.name = name; + this.scope = scope; + this.keys = keys; + this.request = request; + this.nextAllowedTryMs = nextAllowedTryMs; + this.deadlineMs = deadlineMs; + this.tries = tries; + } + } + + /** + * Helper class used to track the request state within each request scope. + * This class enforces a maximum number of inflight request and keeps track + * of backoff/retry state. + */ + private class RequestState { + private Optional<RequestSpec<K>> inflightRequest = Optional.empty(); + private int tries = 0; + private long nextAllowedRetryMs = 0; + + boolean hasInflight() { + return inflightRequest.isPresent(); + } + + public void clearInflight(long currentTimeMs) { + this.inflightRequest = Optional.empty(); + this.nextAllowedRetryMs = currentTimeMs + retryBackoffMs; + } + + public void setInflight(RequestSpec<K> spec) { + this.inflightRequest = Optional.of(spec); + this.tries++; + } + } + + /** + * Completion of the Lookup stage results in a destination broker to send the + * fulfillment request to. Each destination broker in the Fulfillment stage + * gets its own request scope. + */ + private static class BrokerScope implements RequestScope { + public final int destinationBrokerId; + + private BrokerScope(int destinationBrokerId) { + this.destinationBrokerId = destinationBrokerId; + } + + @Override + public OptionalInt destinationBrokerId() { + return OptionalInt.of(destinationBrokerId); + } + + @Override + public boolean equals(Object o) { + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + BrokerScope that = (BrokerScope) o; + return destinationBrokerId == that.destinationBrokerId; + } + + @Override + public int hashCode() { + return Objects.hash(destinationBrokerId); + } + } + + /** + * Helper class which maintains a bi-directional mapping from a key to a set of values. + * Each value can map to one and only one key, but many values can be associated with + * a single key. + * + * @param <K> The key type + * @param <V> The value type + */ + private static class BiMultimap<K, V> { + private final Map<V, K> reverseMap = new HashMap<>(); + private final Map<K, Set<V>> map = new HashMap<>(); + + void put(K key, V value) { + remove(value); + reverseMap.put(value, key); + map.computeIfAbsent(key, k -> new HashSet<>()).add(value); + } + + void remove(V value) { + K key = reverseMap.remove(value); + if (key != null) { + Set<V> set = map.get(key); + if (set != null) { + set.remove(value); + if (set.isEmpty()) { + map.remove(key); + } + } + } + } + + Optional<K> getKey(V value) { + return Optional.ofNullable(reverseMap.get(value)); Review comment: Is this method safe? If there are same values, it would return unrelated key. ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/internals/AdminApiHandler.java ########## @@ -0,0 +1,127 @@ +/* + * 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 org.apache.kafka.clients.admin.internals; + +import org.apache.kafka.common.requests.AbstractRequest; +import org.apache.kafka.common.requests.AbstractResponse; + +import java.util.Collections; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Set; + +public interface AdminApiHandler<K, V> { + + /** + * Get a user-friendly name for the API this handler is implementing. + */ + String apiName(); + + /** + * Initialize the set of keys required to handle this API and how the driver + * should map them to the broker that will handle the request for these keys. + * + * Two mapping types are supported: + * + * - Static mapping: when the brokerId is known ahead of time + * - Dynamic mapping: when the brokerId must be discovered dynamically + * + * @return the key mappings + */ + KeyMappings<K> initializeKeys(); + + /** + * Build the fulfillment request. The set of keys are derived during the Lookup stage + * as the set of keys which all map to the same destination broker. + * + * @param brokerId the target brokerId for the request + * @param keys the set of keys that should be handled by this request + * + * @return a builder for the request containing the given keys + */ + AbstractRequest.Builder<?> buildRequest(Integer brokerId, Set<K> keys); + + /** + * Callback that is invoked when a Fulfillment request returns successfully. + * The handler should parse the response, check for errors, and return a + * result which indicates which keys (if any) have either been completed or + * failed with an unrecoverable error. + * + * It is also possible that the response indicates an incorrect target brokerId + * (e.g. in the case of a NotLeader error when the request is bound for a partition + * leader). In this case the key will be "unmapped" from the target brokerId + * and lookup will be retried. + * + * Note that keys which received a retriable error should be left out of the + * result. They will be retried automatically. + * + * @param brokerId the brokerId that the associated request was sent to + * @param keys the set of keys from the associated request + * @param response the response received from the broker + * + * @return result indicating key complation, failure, and unmapping + */ + ApiResult<K, V> handleResponse(Integer brokerId, Set<K> keys, AbstractResponse response); + + class KeyMappings<K> { + public final Optional<StaticKeyMapping<K>> staticMapping; + public final Optional<DynamicKeyMapping<K>> dynamicMapping; + + public KeyMappings( + Optional<StaticKeyMapping<K>> staticMapping, + Optional<DynamicKeyMapping<K>> dynamicMapping + ) { + this.staticMapping = staticMapping; + this.dynamicMapping = dynamicMapping; + } + } + + class StaticKeyMapping<K> { + public final Map<K, Integer> keys; + + public StaticKeyMapping(Map<K, Integer> keys) { + this.keys = keys; Review comment: Why this field is not wrapped to unmodified stuff? ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/internals/AdminApiLookupStrategy.java ########## @@ -0,0 +1,94 @@ +/* + * 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 org.apache.kafka.clients.admin.internals; + +import org.apache.kafka.common.requests.AbstractRequest; +import org.apache.kafka.common.requests.AbstractResponse; + +import java.util.Collections; +import java.util.Map; +import java.util.OptionalInt; +import java.util.Set; + +public interface AdminApiLookupStrategy<T> { + + /** + * Define the scope of a given key for lookup. Key lookups are complicated + * by the need to accommodate different batching mechanics. For example, + * a `Metadata` request supports arbitrary batching of topic partitions in + * order to discover partitions leaders. This can be supported by returning + * a single scope object for all keys. + * + * On the other hand, `FindCoordinator` request only supports lookup of a + * single key. This can be supported by returning a different scope object + * for each lookup key. + * + * @param key the lookup key + * + * @return request scope indicating how lookup requests can be batched together + */ + RequestScope lookupScope(T key); + + /** + * Build the lookup request for a set of keys. The grouping of the keys is controlled + * through {@link #lookupScope(Object)}. In other words, each set of keys that map + * to the same request scope object will be sent to this method. + * + * @param keys the set of keys that require lookup + * + * @return a builder for the lookup request + */ + AbstractRequest.Builder<?> buildRequest(Set<T> keys); + + /** + * Callback that is invoked when a lookup request returns successfully. The handler + * should parse the response, check for errors, and return a result indicating + * which keys were mapped to a brokerId successfully and which keys received + * a fatal error (e.g. a topic authorization failure). + * + * Note that keys which receive a retriable error should be left out of the + * result. They will be retried automatically. For example, if the response of + * `FindCoordinator` request indicates an unavailable coordinator, then the key + * should be left out of the result so that the request will be retried. + * + * @param keys the set of keys from the associated request + * @param response the response received from the broker + * + * @return a result indicating which keys mapped successfully to a brokerId and + * which encountered a fatal error + */ + LookupResult<T> handleResponse(Set<T> keys, AbstractResponse response); + + class LookupResult<K> { + public final Map<K, Integer> mappedKeys; + public final Map<K, Throwable> failedKeys; + + public LookupResult( + Map<K, Throwable> failedKeys, + Map<K, Integer> mappedKeys + ) { + this.failedKeys = Collections.unmodifiableMap(failedKeys); + this.mappedKeys = Collections.unmodifiableMap(mappedKeys); + } + } + + interface RequestScope { + default OptionalInt destinationBrokerId() { + return OptionalInt.empty(); + }; Review comment: unnecessary `;` ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/DescribeProducersOptions.java ########## @@ -0,0 +1,63 @@ +/* + * 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 org.apache.kafka.clients.admin; + +import org.apache.kafka.common.annotation.InterfaceStability; + +import java.util.Collection; +import java.util.Objects; +import java.util.OptionalInt; + +/** + * Options for {@link Admin#describeProducers(Collection)}. + * + * The API of this class is evolving, see {@link Admin} for details. + */ +@InterfaceStability.Evolving +public class DescribeProducersOptions extends AbstractOptions<DescribeProducersOptions> { + private OptionalInt brokerId = OptionalInt.empty(); + + public DescribeProducersOptions setBrokerId(int brokerId) { + this.brokerId = OptionalInt.of(brokerId); + return this; + } + + public OptionalInt brokerId() { + return brokerId; + } + + @Override + public boolean equals(Object o) { + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + DescribeProducersOptions that = (DescribeProducersOptions) o; + return Objects.equals(brokerId, that.brokerId); Review comment: Should it compare `timeoutMs`? ########## File path: clients/src/main/java/org/apache/kafka/clients/admin/internals/AdminApiHandler.java ########## @@ -0,0 +1,127 @@ +/* + * 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 org.apache.kafka.clients.admin.internals; + +import org.apache.kafka.common.requests.AbstractRequest; +import org.apache.kafka.common.requests.AbstractResponse; + +import java.util.Collections; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Set; + +public interface AdminApiHandler<K, V> { + + /** + * Get a user-friendly name for the API this handler is implementing. + */ + String apiName(); + + /** + * Initialize the set of keys required to handle this API and how the driver + * should map them to the broker that will handle the request for these keys. + * + * Two mapping types are supported: + * + * - Static mapping: when the brokerId is known ahead of time + * - Dynamic mapping: when the brokerId must be discovered dynamically + * + * @return the key mappings + */ + KeyMappings<K> initializeKeys(); + + /** + * Build the fulfillment request. The set of keys are derived during the Lookup stage + * as the set of keys which all map to the same destination broker. + * + * @param brokerId the target brokerId for the request + * @param keys the set of keys that should be handled by this request + * + * @return a builder for the request containing the given keys + */ + AbstractRequest.Builder<?> buildRequest(Integer brokerId, Set<K> keys); + + /** + * Callback that is invoked when a Fulfillment request returns successfully. + * The handler should parse the response, check for errors, and return a + * result which indicates which keys (if any) have either been completed or + * failed with an unrecoverable error. + * + * It is also possible that the response indicates an incorrect target brokerId + * (e.g. in the case of a NotLeader error when the request is bound for a partition + * leader). In this case the key will be "unmapped" from the target brokerId + * and lookup will be retried. + * + * Note that keys which received a retriable error should be left out of the + * result. They will be retried automatically. + * + * @param brokerId the brokerId that the associated request was sent to + * @param keys the set of keys from the associated request + * @param response the response received from the broker + * + * @return result indicating key complation, failure, and unmapping + */ + ApiResult<K, V> handleResponse(Integer brokerId, Set<K> keys, AbstractResponse response); + + class KeyMappings<K> { + public final Optional<StaticKeyMapping<K>> staticMapping; + public final Optional<DynamicKeyMapping<K>> dynamicMapping; + + public KeyMappings( + Optional<StaticKeyMapping<K>> staticMapping, + Optional<DynamicKeyMapping<K>> dynamicMapping + ) { + this.staticMapping = staticMapping; + this.dynamicMapping = dynamicMapping; + } + } + + class StaticKeyMapping<K> { + public final Map<K, Integer> keys; + + public StaticKeyMapping(Map<K, Integer> keys) { + this.keys = keys; + } + } + + class DynamicKeyMapping<K> { + public final Set<K> keys; + public final AdminApiLookupStrategy<K> lookupStrategy; + + public DynamicKeyMapping(Set<K> keys, AdminApiLookupStrategy<K> lookupStrategy) { + this.keys = keys; Review comment: wrap it to unmodified collection? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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