[GOBBLIN-2163] Adding Iceberg TableMetadata Validator

gobblin-data-management/src/main/java/org/apache/gobblin/data/management/copy/iceberg/IcebergPartitionDatasetFinder.java

@@ -46,7 +46,8 @@ public IcebergPartitionDatasetFinder(FileSystem sourceFs, Properties properties)
   @Override
   protected IcebergDataset createSpecificDataset(IcebergTable srcIcebergTable, IcebergTable destIcebergTable,
       Properties properties, FileSystem fs, boolean shouldIncludeMetadataPath) throws IOException {
-//    TODO: Add Validator for source and destination tables later
+    IcebergTableMetadataValidatorUtils.validateSourceAndDestinationTablesMetadata(
+        srcIcebergTable.accessTableMetadata(), destIcebergTable.accessTableMetadata());
 
     String partitionColumnName = getLocationQualifiedProperty(properties, IcebergDatasetFinder.CatalogLocation.SOURCE,
         ICEBERG_PARTITION_NAME_KEY);

gobblin-data-management/src/main/java/org/apache/gobblin/data/management/copy/iceberg/IcebergTableMetadataValidatorUtils.java

@@ -0,0 +1,96 @@
+/*
+ * 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.gobblin.data.management.copy.iceberg;
+
+import java.io.IOException;
+
+import org.apache.iceberg.PartitionSpec;
+import org.apache.iceberg.Schema;
+import org.apache.iceberg.TableMetadata;
+
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * Validator for Iceberg table metadata, ensuring that the source and destination tables have
+ * compatible schemas and partition specifications.
+ */
+@Slf4j
+public class IcebergTableMetadataValidatorUtils {
+
+  private IcebergTableMetadataValidatorUtils() {
+    // Do not instantiate
+  }
+
+  /**
+   * Validates the metadata of the source and destination Iceberg tables.
+   *
+   * @param srcTableMetadata  the metadata of the source table
+   * @param destTableMetadata the metadata of the destination table
+   * @throws IOException if the schemas or partition specifications do not match
+   */
+  public static void validateSourceAndDestinationTablesMetadata(TableMetadata srcTableMetadata,
+      TableMetadata destTableMetadata) throws IOException {
+    log.info("Starting validation of Source : {} and Destination : {} Iceberg Tables Metadata",
+        srcTableMetadata.location(),
+        destTableMetadata.location());
+    Schema srcTableSchema = srcTableMetadata.schema();
+    Schema destTableSchema = destTableMetadata.schema();
+    PartitionSpec srcPartitionSpec = srcTableMetadata.spec();
+    PartitionSpec destPartitionSpec = destTableMetadata.spec();
+    validateSchemaForEquality(srcTableSchema, destTableSchema);
+    validatePartitionSpecForEquality(srcPartitionSpec, destPartitionSpec);
+    log.info("Validation of Source : {} and Destination : {} Iceberg Tables Metadata completed successfully",
+        srcTableMetadata.location(),
+        destTableMetadata.location());
+  }
+
+  private static void validateSchemaForEquality(Schema srcTableSchema, Schema destTableSchema) throws IOException {
+    // TODO: Need to add support for schema evolution, currently only supporting copying
+    //  between iceberg tables with same schema.
+    //  This function needs to be broken down into multiple functions to support schema evolution
+    //  Possible cases - Src Schema == Dest Schema,
+    //  - Src Schema is subset of Dest Schema [ Destination Schema Evolved ],
+    //  - Src Schema is superset of Dest Schema [ Source Schema Evolved ],
+    //  - Other cases?
+    //  Also consider using Strategy or any other design pattern for this to make it a better solution
+    if (!srcTableSchema.sameSchema(destTableSchema)) {
+      String errMsg = String.format(
+          "Schema Mismatch between Source and Destination Iceberg Tables Schema - Source-Schema-Id : {%s} and "
+              + "Destination-Schema-Id : {%s}",
+          srcTableSchema.schemaId(),
+          destTableSchema.schemaId()
+      );
+      log.error(errMsg);
+      throw new IOException(errMsg);
+    }
+  }
+
+  private static void validatePartitionSpecForEquality(PartitionSpec srcPartitionSpec, PartitionSpec destPartitionSpec)
+      throws IOException {
+    // Currently, only supporting copying between iceberg tables with same partition spec
+    if (!srcPartitionSpec.compatibleWith(destPartitionSpec)) {
+      String errMsg = String.format(
+          "Partition Spec Mismatch between Source and Destination Iceberg Tables Partition Spec - Source : {%s} and Destination : {%s}",
+          srcPartitionSpec,
+          destPartitionSpec
+      );
+      log.error(errMsg);
+      throw new IOException(errMsg);
+    }
+  }
+}

gobblin-data-management/src/test/java/org/apache/gobblin/data/management/copy/iceberg/IcebergTableMetadataValidatorUtilsTest.java

@@ -0,0 +1,186 @@
+/*
+ * 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.gobblin.data.management.copy.iceberg;
+
+import java.io.IOException;
+import java.util.HashMap;
+
+import org.apache.iceberg.PartitionSpec;
+import org.apache.iceberg.TableMetadata;
+import org.apache.iceberg.avro.AvroSchemaUtil;
+import org.apache.iceberg.Schema;
+import org.apache.iceberg.shaded.org.apache.avro.SchemaBuilder;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+public class IcebergTableMetadataValidatorUtilsTest {
+  private static final org.apache.iceberg.shaded.org.apache.avro.Schema avroDataSchema1 =
+      SchemaBuilder.record("schema1")
+          .fields()
+          .requiredString("field1")
+          .requiredString("field2")
+          .endRecord();
+  private static final org.apache.iceberg.shaded.org.apache.avro.Schema avroDataSchema2 =
+      SchemaBuilder.record("schema2")
+          .fields()
+          .requiredString("field2")
+          .requiredString("field1")
+          .endRecord();
+  private static final org.apache.iceberg.shaded.org.apache.avro.Schema avroDataSchema3 =
+      SchemaBuilder.record("schema3")
+          .fields()
+          .requiredString("field1")
+          .requiredString("field2")
+          .requiredInt("field3")
+          .endRecord();
+  private static final org.apache.iceberg.shaded.org.apache.avro.Schema avroDataSchema4 =
+      SchemaBuilder.record("schema4")
+          .fields()
+          .requiredInt("field1")
+          .requiredString("field2")
+          .requiredInt("field3")
+          .endRecord();
+  private static final PartitionSpec unpartitionedPartitionSpec = PartitionSpec.unpartitioned();
+  private static final Schema schema1 = AvroSchemaUtil.toIceberg(avroDataSchema1);
+  private static final Schema schema2IsNotSchema1Compat = AvroSchemaUtil.toIceberg(avroDataSchema2);
+  private static final Schema schema3 = AvroSchemaUtil.toIceberg(avroDataSchema3);
+  private static final Schema schema4IsNotSchema3Compat = AvroSchemaUtil.toIceberg(avroDataSchema4);
+  private static final PartitionSpec partitionSpec1 = PartitionSpec.builderFor(schema1)
+      .identity("field1")
+      .build();
+  private static final TableMetadata tableMetadataWithSchema1AndUnpartitionedSpec = TableMetadata.newTableMetadata(
+      schema1, unpartitionedPartitionSpec, "metadataLocationWithSchema1AndUnpartitionedSpec", new HashMap<>());
+  private static final TableMetadata tableMetadataWithSchema1AndPartitionSpec1 = TableMetadata.newTableMetadata(
+      schema1, partitionSpec1, "metadataLocationWithSchema2AndUnpartitionedSpec", new HashMap<>());
+  private static final TableMetadata tableMetadataWithSchema3AndUnpartitionedSpec = TableMetadata.newTableMetadata(
+      schema3, unpartitionedPartitionSpec, "metadataLocationWithSchema1AndUnpartitionedSpec", new HashMap<>());
+  private static final String SCHEMA_MISMATCH_EXCEPTION = "Schema Mismatch between Source and Destination Iceberg Tables Schema";
+  private static final String PARTITION_SPEC_MISMATCH_EXCEPTION = "Partition Spec Mismatch between Source and Destination Iceberg Tables Partition Spec";
+  @Test
+  public void testValidateSameSchema() throws IOException {
+    IcebergTableMetadataValidatorUtils.validateSourceAndDestinationTablesMetadata(
+        tableMetadataWithSchema1AndUnpartitionedSpec, tableMetadataWithSchema1AndUnpartitionedSpec
+    );
+  }
+
+  @Test
+  public void testValidateDifferentSchema() {
+    // Schema 1 and Schema 2 have different field order
+
+    TableMetadata destTableMetadata = TableMetadata.newTableMetadata(schema2IsNotSchema1Compat,
+        unpartitionedPartitionSpec, "destMetadataLocationForSchema2", new HashMap<>());
+
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema1AndUnpartitionedSpec,
+        destTableMetadata, SCHEMA_MISMATCH_EXCEPTION);
+  }
+
+  @Test
+  public void testValidateSchemaWithDifferentTypes() {
+    // schema 3 and schema 4 have different field types for field1
+
+    TableMetadata destTableMetadata = TableMetadata.newTableMetadata(schema4IsNotSchema3Compat,
+        unpartitionedPartitionSpec, "destMetadataLocationForSchema4", new HashMap<>());
+
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema3AndUnpartitionedSpec,
+        destTableMetadata, SCHEMA_MISMATCH_EXCEPTION);
+  }
+
+  @Test
+  public void testValidateSchemaWithEvolvedDestinationSchema() {
+    // TODO: This test should pass in the future when we support source side schema evolution and here there should
+    //  not be any commit needed on destination side
+    // Schema 3 has one more extra field as compared to Schema 1
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema1AndUnpartitionedSpec,
+        tableMetadataWithSchema3AndUnpartitionedSpec, SCHEMA_MISMATCH_EXCEPTION);
+  }
+
+  @Test
+  public void testValidateSchemaWithEvolvedSourceSchema() {
+    // TODO: This test should pass in the future when we support source side schema evolution and commit the changes
+    //  on destination side either through IcebergRegisterStep or any other CommitStep
+    // Schema 3 has one more extra field as compared to Schema 1
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema3AndUnpartitionedSpec,
+        tableMetadataWithSchema1AndUnpartitionedSpec, SCHEMA_MISMATCH_EXCEPTION);
+  }
+
+  @Test
+  public void testValidateEvolvedSourceSchemaFromIntToLongType() {
+    // Adding this test as to verify that partition copy doesn't proceed further for this case
+    // as while doing poc and testing had seen final commit gets fail if there is mismatch in field type
+    // specially from int to long
+    org.apache.iceberg.shaded.org.apache.avro.Schema avroDataSchema =
+        SchemaBuilder.record("schema5")
+            .fields()
+            .requiredLong("field1")
+            .requiredString("field2")
+            .requiredInt("field3")
+            .endRecord();
+    Schema schema5EvolvedFromSchema4 = AvroSchemaUtil.toIceberg(avroDataSchema);
+    PartitionSpec partitionSpec = PartitionSpec.builderFor(schema5EvolvedFromSchema4)
+        .identity("field1")
+        .build();
+    TableMetadata destTableMetadata = TableMetadata.newTableMetadata(schema5EvolvedFromSchema4, partitionSpec,
+        "destMetadataLocationForSchema5", new HashMap<>());
+
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema1AndUnpartitionedSpec,
+        destTableMetadata, SCHEMA_MISMATCH_EXCEPTION);
+  }
+
+  @Test
+  public void testValidateSamePartitionSpec() throws IOException {
+    IcebergTableMetadataValidatorUtils.validateSourceAndDestinationTablesMetadata(
+        tableMetadataWithSchema1AndPartitionSpec1, tableMetadataWithSchema1AndPartitionSpec1
+    );
+  }
+
+  @Test
+  public void testValidatePartitionSpecWithDiffName() {
+    PartitionSpec partitionSpec12 = PartitionSpec.builderFor(schema1)
+        .identity("field2")
+        .build();
+    TableMetadata destTableMetadata = TableMetadata.newTableMetadata(schema1, partitionSpec12,
+        "destMetadataLocationForSchema1", new HashMap<>());
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema1AndPartitionSpec1,
+        destTableMetadata, PARTITION_SPEC_MISMATCH_EXCEPTION);
+  }
+
+  @Test
+  public void testValidatePartitionSpecWithUnpartitioned() {
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema1AndUnpartitionedSpec,
+        tableMetadataWithSchema1AndPartitionSpec1, PARTITION_SPEC_MISMATCH_EXCEPTION);
+  }
+
+  @Test
+  public void testPartitionSpecWithDifferentTransform() {
+    PartitionSpec partitionSpec12 = PartitionSpec.builderFor(schema1)
+        .truncate("field1", 4)
+        .build();
+    TableMetadata destTableMetadata = TableMetadata.newTableMetadata(schema1, partitionSpec12,
+        "destMetadataLocationForSchema1", new HashMap<>());
+    verifyValidateSourceAndDestinationTablesMetadataIOException(tableMetadataWithSchema1AndPartitionSpec1,
+        destTableMetadata, PARTITION_SPEC_MISMATCH_EXCEPTION);
+  }
+
+  private void verifyValidateSourceAndDestinationTablesMetadataIOException(TableMetadata srcTableMetadata,
+      TableMetadata destTableMetadata, String expectedMessage) {
+    IOException exception = Assert.expectThrows(IOException.class, () -> {
+      IcebergTableMetadataValidatorUtils.validateSourceAndDestinationTablesMetadata(srcTableMetadata, destTableMetadata);
+    });
+    Assert.assertTrue(exception.getMessage().startsWith(expectedMessage));
+  }
+}