openinx commented on a change in pull request #1185: URL: https://github.com/apache/iceberg/pull/1185#discussion_r479951122
########## File path: flink/src/main/java/org/apache/iceberg/flink/sink/IcebergFilesCommitter.java ########## @@ -0,0 +1,229 @@ +/* + * 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.iceberg.flink.sink; + +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.NavigableMap; +import java.util.SortedMap; +import org.apache.flink.api.common.state.ListState; +import org.apache.flink.api.common.state.ListStateDescriptor; +import org.apache.flink.api.common.typeinfo.BasicTypeInfo; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.api.java.typeutils.ListTypeInfo; +import org.apache.flink.runtime.state.StateInitializationContext; +import org.apache.flink.runtime.state.StateSnapshotContext; +import org.apache.flink.streaming.api.operators.AbstractStreamOperator; +import org.apache.flink.streaming.api.operators.BoundedOneInput; +import org.apache.flink.streaming.api.operators.OneInputStreamOperator; +import org.apache.flink.streaming.runtime.streamrecord.StreamRecord; +import org.apache.flink.table.runtime.typeutils.SortedMapTypeInfo; +import org.apache.hadoop.conf.Configuration; +import org.apache.iceberg.AppendFiles; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.Snapshot; +import org.apache.iceberg.Table; +import org.apache.iceberg.flink.TableLoader; +import org.apache.iceberg.hadoop.SerializableConfiguration; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.types.Comparators; +import org.apache.iceberg.types.Types; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +class IcebergFilesCommitter extends AbstractStreamOperator<Void> + implements OneInputStreamOperator<DataFile, Void>, BoundedOneInput { + + private static final long serialVersionUID = 1L; + private static final long INITIAL_CHECKPOINT_ID = -1L; + + private static final Logger LOG = LoggerFactory.getLogger(IcebergFilesCommitter.class); + private static final String FLINK_JOB_ID = "flink.job-id"; + + // The max checkpoint id we've committed to iceberg table. As the flink's checkpoint is always increasing, so we could + // correctly commit all the data files whose checkpoint id is greater than the max committed one to iceberg table, for + // avoiding committing the same data files twice. This id will be attached to iceberg's meta when committing the + // iceberg transaction. + private static final String MAX_COMMITTED_CHECKPOINT_ID = "flink.max-committed-checkpoint-id"; + + // TableLoader to load iceberg table lazily. + private final TableLoader tableLoader; + private final SerializableConfiguration hadoopConf; + + // A sorted map to maintain the completed data files for each pending checkpointId (which have not been committed + // to iceberg table). We need a sorted map here because there's possible that few checkpoints snapshot failed, for + // example: the 1st checkpoint have 2 data files <1, <file0, file1>>, the 2st checkpoint have 1 data files + // <2, <file3>>. Snapshot for checkpoint#1 interrupted because of network/disk failure etc, while we don't expect + // any data loss in iceberg table. So we keep the finished files <1, <file0, file1>> in memory and retry to commit + // iceberg table when the next checkpoint happen. + private final NavigableMap<Long, List<DataFile>> dataFilesPerCheckpoint = Maps.newTreeMap(); + + // The data files cache for current checkpoint. Once the snapshot barrier received, it will be flushed to the + // 'dataFilesPerCheckpoint'. + private final List<DataFile> dataFilesOfCurrentCheckpoint = Lists.newArrayList(); + + // It will have an unique identifier for one job. + private transient String flinkJobId; + private transient Table table; + private transient long maxCommittedCheckpointId; + + // All pending checkpoints states for this function. + private static final ListStateDescriptor<SortedMap<Long, List<DataFile>>> STATE_DESCRIPTOR = buildStateDescriptor(); + private transient ListState<SortedMap<Long, List<DataFile>>> checkpointsState; + + IcebergFilesCommitter(TableLoader tableLoader, Configuration hadoopConf) { + this.tableLoader = tableLoader; + this.hadoopConf = new SerializableConfiguration(hadoopConf); + } + + @Override + public void initializeState(StateInitializationContext context) throws Exception { + super.initializeState(context); + this.flinkJobId = getContainingTask().getEnvironment().getJobID().toString(); + + // Open the table loader and load the table. + this.tableLoader.open(hadoopConf.get()); + this.table = tableLoader.loadTable(); + this.maxCommittedCheckpointId = INITIAL_CHECKPOINT_ID; + + this.checkpointsState = context.getOperatorStateStore().getListState(STATE_DESCRIPTOR); + if (context.isRestored()) { + this.maxCommittedCheckpointId = getMaxCommittedCheckpointId(table, flinkJobId); + // In the restoring path, it should have one valid snapshot for current flink job at least, so the max committed + // checkpoint id should be positive. If it's not positive, that means someone might have removed or expired the + // iceberg snapshot, in that case we should throw an exception in case of committing duplicated data files into + // the iceberg table. + Preconditions.checkState(maxCommittedCheckpointId != INITIAL_CHECKPOINT_ID, + "There should be an existing iceberg snapshot for current flink job: %s", flinkJobId); + + SortedMap<Long, List<DataFile>> restoredDataFiles = checkpointsState.get().iterator().next(); + // Only keep the uncommitted data files in the cache. + this.dataFilesPerCheckpoint.putAll(restoredDataFiles.tailMap(maxCommittedCheckpointId + 1)); Review comment: Committing those uncommitted data files here immediately sounds good to me, it should won't impact the correctness 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. 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