Mmuzaf commented on a change in pull request #8909: URL: https://github.com/apache/ignite/pull/8909#discussion_r601767565
########## File path: modules/core/src/main/java/org/apache/ignite/internal/cdc/IgniteCDC.java ########## @@ -0,0 +1,485 @@ +/* + * 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.ignite.internal.cdc; + +import java.io.File; +import java.io.IOException; +import java.io.Serializable; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.ArrayList; +import java.util.Comparator; +import java.util.HashSet; +import java.util.Iterator; +import java.util.List; +import java.util.Set; +import java.util.UUID; +import java.util.function.Predicate; +import java.util.stream.Stream; +import org.apache.ignite.IgniteCheckedException; +import org.apache.ignite.IgniteException; +import org.apache.ignite.IgniteLogger; +import org.apache.ignite.cdc.CaptureDataChangeConfiguration; +import org.apache.ignite.cdc.CaptureDataChangeConsumer; +import org.apache.ignite.cdc.ChangeEvent; +import org.apache.ignite.configuration.DataStorageConfiguration; +import org.apache.ignite.configuration.IgniteConfiguration; +import org.apache.ignite.internal.IgnitionEx; +import org.apache.ignite.internal.MarshallerContextImpl; +import org.apache.ignite.internal.pagemem.wal.WALIterator; +import org.apache.ignite.internal.processors.cache.binary.CacheObjectBinaryProcessorImpl; +import org.apache.ignite.internal.processors.cache.persistence.filename.PdsConsistentIdProcessor; +import org.apache.ignite.internal.processors.cache.persistence.wal.WALPointer; +import org.apache.ignite.internal.processors.cache.persistence.wal.reader.IgniteWalIteratorFactory; +import org.apache.ignite.internal.util.typedef.F; +import org.apache.ignite.internal.util.typedef.internal.CU; +import org.apache.ignite.internal.util.typedef.internal.U; +import org.apache.ignite.lang.IgniteBiTuple; + +import static org.apache.ignite.configuration.DataStorageConfiguration.DFLT_CDC_PATH; +import static org.apache.ignite.internal.pagemem.wal.record.WALRecord.RecordType.DATA_RECORD_V2; +import static org.apache.ignite.internal.processors.cache.persistence.filename.PdsConsistentIdProcessor.NODE_PATTERN; +import static org.apache.ignite.internal.processors.cache.persistence.filename.PdsConsistentIdProcessor.UUID_STR_PATTERN; +import static org.apache.ignite.internal.processors.cache.persistence.wal.FileWriteAheadLogManager.WAL_NAME_PATTERN; + +/** + * CDC(Capture Data Change) application. + * Application run independently of Ignite node process and provide ability for the {@link CaptureDataChangeConsumer} to consume events({@link ChangeEvent}) from WAL segments. + * User should responsible {@link CaptureDataChangeConsumer} implementation with custom consumption logic. + * + * Ignite node should be explicitly configured for using {@link IgniteCDC}. + * <ol> + * <li>Set {@link DataStorageConfiguration#setCdcEnabled(boolean)} to true.</li> + * <li>Optional: Set {@link DataStorageConfiguration#setCdcPath(String)} to path to the directory to store WAL setgments for CDC.</li> + * <li>Optional: Set {@link DataStorageConfiguration#setWalForceArchiveTimeout(long)} to configure timeout for force WAL rollover, + * so new events will be available for consumptions with the predicted time.</li> + * </ol> + * + * When {@link DataStorageConfiguration#getCdcPath()} is true then Ignite node on each WAL segment rollover creates hard link + * to archive WAL segment in {@link DataStorageConfiguration#getCdcPath()} directory. + * {@link IgniteCDC} application takes segment file and consumes events from it. After successfull consumption (see {@link CaptureDataChangeConsumer#onChange(Iterator)}) + * WAL segement will be deleted from directory. + * + * Several Ignite nodes can be started on the same host. + * If your deployment done with custom consistent id then you should specify it via {@link IgniteConfiguration#setConsistentId(Serializable)} in provided {@link IgniteConfiguration}. + * Otherwise you should specify auto generated consistent id and node index with the following options: + * <ul> + * <li>{@link CaptureDataChangeConfiguration#setAutoGeneratedConsistentId(UUID)}.</li> + * <li>{@link CaptureDataChangeConfiguration#setNodeIndex(int)}.</li> + * </ul> + * + * Application works as follows: + * <ol> + * <li>Search node work directory based on provided {@link IgniteConfiguration} and system properties.</li> + * <li>Await for creation of CDC directory if it not exists.</li> + * <li>Acquire file lock to ensure exclusive consumption.</li> + * <li>Loads state of consumption if it exists.</li> + * <li>Infinetely wait for new available segement and process it.</li> Review comment: segement > segment -- This is an automated message from the Apache Git Service. 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