ahmedabu98 commented on code in PR #38837: URL: https://github.com/apache/beam/pull/38837#discussion_r3589979900
########## sdks/java/io/iceberg/src/main/java/org/apache/beam/sdk/io/iceberg/cdc/LocalResolveDoFn.java: ########## @@ -0,0 +1,245 @@ +/* + * 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.beam.sdk.io.iceberg.cdc; + +import static org.apache.beam.sdk.io.iceberg.IcebergUtils.icebergSchemaToBeamSchema; +import static org.apache.beam.sdk.io.iceberg.cdc.SerializableChangelogTask.Type.ADDED_ROWS; +import static org.apache.beam.sdk.util.Preconditions.checkStateNotNull; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Comparator; +import java.util.HashSet; +import java.util.List; +import java.util.Objects; +import java.util.Set; +import java.util.stream.Collectors; +import org.apache.beam.sdk.io.iceberg.IcebergScanConfig; +import org.apache.beam.sdk.io.iceberg.IcebergUtils; +import org.apache.beam.sdk.io.iceberg.TableCache; +import org.apache.beam.sdk.transforms.DoFn; +import org.apache.beam.sdk.transforms.join.CoGroupByKey; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.Row; +import org.apache.beam.sdk.values.ValueKind; +import org.apache.iceberg.Schema; +import org.apache.iceberg.Snapshot; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableProperties; +import org.apache.iceberg.data.Record; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.types.Comparators; +import org.apache.iceberg.types.TypeUtil; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.StructLikeMap; +import org.apache.iceberg.util.StructLikeUtil; +import org.apache.iceberg.util.StructProjection; +import org.checkerframework.checker.nullness.qual.MonotonicNonNull; +import org.checkerframework.checker.nullness.qual.Nullable; + +/** + * Resolves a small bi-directional changelog group entirely in memory. This is the equivalent of + * {@link ReadFromChangelogs} + {@link CoGroupByKey} + {@link ResolveChanges}. + * + * <p>All tasks in a changelog group belong to the same Iceberg {@link Snapshot}. The upstream + * {@link ChangelogScanner} routes here only when the total size of the bi-directional group fits + * within {@link TableProperties#SPLIT_SIZE}. + * + * <p>The incoming batch's overlap region has already been computed in the scanning phase by {@link + * ChangelogScanner}. In this DoFn, we just process each task and route records: + * + * <ul> + * <li>Records whose PK falls <b>outside</b> the overlap range cannot have an opposing-side match, + * so they are emitted directly with {@code INSERT} or {@code DELETE} kind. + * <li>Records whose PK falls <b>inside</b> the overlap range are stashed in a {@link + * StructLikeMap} keyed by PK, then resolved by {@link CdcResolver}. + * </ul> + */ +class LocalResolveDoFn extends DoFn<KV<ChangelogDescriptor, List<SerializableChangelogTask>>, Row> { + private final IcebergScanConfig scanConfig; + private final org.apache.beam.sdk.schemas.Schema projectedBeamSchema; + private final org.apache.beam.sdk.schemas.Schema outputBeamSchema; + + private transient @MonotonicNonNull OverlapRange overlap; + private transient @MonotonicNonNull List<Types.NestedField> nonPkFields; + private transient @MonotonicNonNull StructProjection projector; + + LocalResolveDoFn(IcebergScanConfig scanConfig) { + this.scanConfig = scanConfig; + this.projectedBeamSchema = + CdcOutputUtils.readBeamSchemaWithRowMetadata( + scanConfig.getMetadataColumns(), scanConfig.getProjectedSchema()); + this.outputBeamSchema = + CdcOutputUtils.outputSchema( + scanConfig, icebergSchemaToBeamSchema(scanConfig.getProjectedSchema())); + } + + @Setup + public void setup() { + Schema tableSchema = + TableCache.get(scanConfig.getCatalogConfig(), scanConfig.getTableIdentifier()).schema(); + Schema fullReadSchema = + CdcOutputUtils.readSchemaWithRowMetadata(scanConfig.getMetadataColumns(), tableSchema); + this.overlap = OverlapRange.forScanConfig(scanConfig); + Set<String> pkFieldNames = new HashSet<>(overlap.recordIdSchema().identifierFieldNames()); + // The dedup logic only inspects non-PK fields, so precompute them once. + List<Types.NestedField> nonPk = new ArrayList<>(); + for (Types.NestedField f : tableSchema.columns()) { + if (!pkFieldNames.contains(f.name())) { + nonPk.add(f); + } + } + this.nonPkFields = nonPk; + this.projector = + StructProjection.create( + fullReadSchema, + CdcOutputUtils.readSchemaWithRowMetadata( + scanConfig.getMetadataColumns(), scanConfig.getProjectedSchema())); + } + + @ProcessElement + public void process( + @Element KV<ChangelogDescriptor, List<SerializableChangelogTask>> element, + OutputReceiver<Row> out) + throws IOException { + ChangelogDescriptor descriptor = element.getKey(); + Table table = TableCache.get(scanConfig.getCatalogConfig(), scanConfig.getTableIdentifier()); + OverlapRange ovl = checkStateNotNull(overlap); + + // {PK: (inserts | deletes)} for in-overlap records that need resolution. + // Records outside the overlap are emitted directly + StructLikeMap<PkGroup> pkGroups = StructLikeMap.create(ovl.recordIdSchema().asStruct()); Review Comment: I added a scaling factor in ChangelogScanner to make a rough estimate of the decoded bytes. This reduces the byte size threshold of batches getting routed to LocalResolveDoFn, so we won't see big batches making it there. Should help us avoid OOMs, and we can adjust the factor when we see how it's handled with real usage -- 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]
