jberragan commented on code in PR #294: URL: https://github.com/apache/cassandra-sidecar/pull/294#discussion_r2637003968
########## server/src/main/java/org/apache/cassandra/sidecar/cdc/CdcManager.java: ########## @@ -0,0 +1,282 @@ +/* + * 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.cassandra.sidecar.cdc; + +import java.io.IOException; +import java.net.InetAddress; +import java.net.UnknownHostException; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.stream.Collectors; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.cassandra.cdc.api.CdcOptions; +import org.apache.cassandra.cdc.api.EventConsumer; +import org.apache.cassandra.cdc.api.SchemaSupplier; +import org.apache.cassandra.cdc.api.TokenRangeSupplier; +import org.apache.cassandra.cdc.sidecar.CdcSidecarInstancesProvider; +import org.apache.cassandra.cdc.sidecar.ClusterConfigProvider; +import org.apache.cassandra.cdc.sidecar.SidecarCdc; +import org.apache.cassandra.cdc.sidecar.SidecarCdcClient; +import org.apache.cassandra.cdc.sidecar.SidecarCdcStats; +import org.apache.cassandra.cdc.sidecar.SidecarStatePersister; +import org.apache.cassandra.cdc.stats.ICdcStats; +import org.apache.cassandra.secrets.SecretsProvider; +import org.apache.cassandra.sidecar.cluster.instance.InstanceMetadata; +import org.apache.cassandra.sidecar.common.server.cluster.locator.TokenRange; +import org.apache.cassandra.sidecar.concurrent.TaskExecutorPool; +import org.apache.cassandra.sidecar.coordination.RangeManager; +import org.apache.cassandra.sidecar.db.CdcDatabaseAccessor; +import org.apache.cassandra.sidecar.utils.InstanceMetadataFetcher; +import org.apache.cassandra.spark.utils.AsyncExecutor; +import org.jetbrains.annotations.NotNull; + + +/** + * Manages the lifecycle and coordination of CDC (Change Data Capture) consumers for processing + * Cassandra change events across distributed token ranges. + * + * <p>This class is responsible for: + * <ul> + * <li>Building and configuring {@link SidecarCdc} consumers based on owned token ranges</li> + * <li>Deduplicating consumers by instance ID and token range to prevent duplicate processing</li> + * <li>Managing consumer lifecycle (start/stop operations)</li> + * <li>Integrating with various providers for cluster configuration, schema, and instance metadata</li> + * <li>Coordinating with the range manager to determine token ownership</li> + * </ul> + * + * <p>The CDC consumers created by this manager process change events from Cassandra commit logs + * and forward them to configured event consumers (such as Kafka producers) while maintaining + * state persistence and proper token range distribution across the cluster. + * + * @see SidecarCdc + * @see EventConsumer + * @see RangeManager + * @see CdcConfig + */ +public class CdcManager +{ + private static final Logger LOGGER = LoggerFactory.getLogger(CdcManager.class); + private final CdcConfig conf; + private final RangeManager rangeManager; + private final InstanceMetadataFetcher instanceFetcher; + private final EventConsumer eventConsumer; + private final SchemaSupplier schemaSupplier; + private final ClusterConfigProvider clusterConfigProvider; + private final CdcSidecarInstancesProvider sidecarInstancesProvider; + private final SecretsProvider secretsProvider; + private final SidecarCdcClient.ClientConfig clientConfig; + private final ICdcStats cdcStats; + private List<SidecarCdc> consumers = new ArrayList<>(); + private final TaskExecutorPool taskExecutorPool; + private final CdcDatabaseAccessor cdcDatabaseAccessor; + + + public CdcManager(EventConsumer eventConsumer, + SchemaSupplier schemaSupplier, + CdcConfig conf, + RangeManager rangeManager, + InstanceMetadataFetcher instanceFetcher, + ClusterConfigProvider clusterConfigProvider, + CdcSidecarInstancesProvider sidecarInstancesProvider, + SecretsProvider secretsProvider, + SidecarCdcClient.ClientConfig clientConfig, + ICdcStats cdcStats, + TaskExecutorPool taskExecutorPool, + CdcDatabaseAccessor cdcDatabaseAccessor) + { + this.eventConsumer = eventConsumer; + this.schemaSupplier = schemaSupplier; + this.conf = conf; + this.rangeManager = rangeManager; + this.instanceFetcher = instanceFetcher; + this.clusterConfigProvider = clusterConfigProvider; + this.sidecarInstancesProvider = sidecarInstancesProvider; + this.secretsProvider = secretsProvider; + this.clientConfig = clientConfig; + this.cdcStats = cdcStats; + this.taskExecutorPool = taskExecutorPool; + this.cdcDatabaseAccessor = cdcDatabaseAccessor; + } + + List<SidecarCdc> buildCdcConsumers() + { + Map<String, Set<TokenRange>> ownedRanges = rangeManager.ownedTokenRanges(); + if (ownedRanges == null || ownedRanges.isEmpty()) + { + throw new IllegalStateException("No owned token ranges right now, cql session may still be initializing."); + } + + // NEW: Deduplicate by (instanceId, tokenRange) to prevent duplicate consumers + Map<String, SidecarCdc> uniqueConsumers = new HashMap<>(); + + ownedRanges.entrySet().stream() + .flatMap(entry -> + entry.getValue().stream().map(range -> { + Integer instanceId = getInstanceId(entry.getKey()); + + // Create unique key: "instanceId:rangeStart:rangeEnd" + String uniqueKey = String.format("%d:%s:%s", + instanceId, + range.startAsBigInt(), + range.endAsBigInt()); + + // Only create consumer if not already created for this (instance, range) + return uniqueConsumers.computeIfAbsent(uniqueKey, k -> { + try + { + return loadOrBuildCdcConsumer(instanceId, + clusterConfigProvider, + eventConsumer, + schemaSupplier, + () -> org.apache.cassandra.bridge.TokenRange.openClosed(range.startAsBigInt(), range.endAsBigInt()), + sidecarInstancesProvider, + secretsProvider, + clientConfig, + conf, + cdcStats, + taskExecutorPool); + } + catch (IOException e) + { + throw new RuntimeException(e); + } + }); + })) + .collect(Collectors.toList()); + + consumers = new ArrayList<>(uniqueConsumers.values()); + return consumers; + } + + SidecarCdc loadOrBuildCdcConsumer(Integer instanceId, + ClusterConfigProvider clusterConfigProvider, + EventConsumer eventConsumer, + SchemaSupplier schemaSupplier, + TokenRangeSupplier tokenRangeSupplier, + CdcSidecarInstancesProvider sidecarInstancesProvider, + SecretsProvider secretsProvider, + SidecarCdcClient.ClientConfig clientConfig, + CdcConfig conf, + ICdcStats cdcStats, + TaskExecutorPool taskExecutorPool) throws IOException + { + return buildConsumer(conf.jobId(), + instanceId, + new SidecarCdcOptions(instanceFetcher), + clusterConfigProvider, + eventConsumer, + schemaSupplier, + tokenRangeSupplier, + sidecarInstancesProvider, + clientConfig, + secretsProvider, + cdcStats, + taskExecutorPool); + } + + public void startConsumers() + { + consumers.forEach(SidecarCdc::initSchema); + consumers.forEach(SidecarCdc::start); + } + + public void stopConsumers() + { + consumers.forEach(SidecarCdc::stop); + } + + private Integer getInstanceId(String instanceIp) + { + for (InstanceMetadata instance : instanceFetcher.allLocalInstances()) + { + String configuredHost = instance.ipAddress(); + + // Option 1a: Normalize both to InetAddress and compare + if (resolveToSameAddress(instanceIp, configuredHost)) + { + return instance.id(); + } + } + LOGGER.warn("Requested IP {} does not match with any instances", instanceIp); + return -1; + } + + private boolean resolveToSameAddress(String host1, String host2) Review Comment: It seems like this only expects ip addresses to be input, and so will not perform DNS resolution. Can we make that explicit? We can also make the method static and add some unit tests here. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
