[HUDI-3921] Fixed schema evolution cannot work with HUDI-3855 (#5376)

- when columns names are renamed (schema evolution enabled), while copying records from old data file with HoodieMergeHande, renamed columns wasn't handled well.

Author: xiarixiaoyao

hudi-client/hudi-client-common/src/main/java/org/apache/hudi/io/HoodieWriteHandle.java

@@ -46,6 +46,9 @@
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
+import java.util.HashMap;
+
+import static org.apache.hudi.common.util.StringUtils.isNullOrEmpty;
 
 /**
  * Base class for all write operations logically performed at the file group level.
@@ -98,6 +101,8 @@ public abstract class HoodieWriteHandle<T extends HoodieRecordPayload, I, K, O>
   protected final String fileId;
   protected final String writeToken;
   protected final TaskContextSupplier taskContextSupplier;
+  // For full schema evolution
+  protected final boolean schemaOnReadEnabled;
 
   public HoodieWriteHandle(HoodieWriteConfig config, String instantTime, String partitionPath,
                            String fileId, HoodieTable<T, I, K, O> hoodieTable, TaskContextSupplier taskContextSupplier) {
@@ -120,6 +125,7 @@ protected HoodieWriteHandle(HoodieWriteConfig config, String instantTime, String
         !hoodieTable.getIndex().isImplicitWithStorage(), config.getWriteStatusFailureFraction());
     this.taskContextSupplier = taskContextSupplier;
     this.writeToken = makeWriteToken();
+    schemaOnReadEnabled = !isNullOrEmpty(hoodieTable.getConfig().getInternalSchema());
   }
 
   /**
@@ -224,11 +230,13 @@ public void write(HoodieRecord record, Option<IndexedRecord> avroRecord, Option<
    * Rewrite the GenericRecord with the Schema containing the Hoodie Metadata fields.
    */
   protected GenericRecord rewriteRecord(GenericRecord record) {
-    return HoodieAvroUtils.rewriteRecord(record, writeSchemaWithMetaFields);
+    return schemaOnReadEnabled ? HoodieAvroUtils.rewriteRecordWithNewSchema(record, writeSchemaWithMetaFields, new HashMap<>())
+        : HoodieAvroUtils.rewriteRecord(record, writeSchemaWithMetaFields);
   }
 
   protected GenericRecord rewriteRecordWithMetadata(GenericRecord record, String fileName) {
-    return HoodieAvroUtils.rewriteRecordWithMetadata(record, writeSchemaWithMetaFields, fileName);
+    return schemaOnReadEnabled ? HoodieAvroUtils.rewriteEvolutionRecordWithMetadata(record, writeSchemaWithMetaFields, fileName)
+        : HoodieAvroUtils.rewriteRecordWithMetadata(record, writeSchemaWithMetaFields, fileName);
   }
 
   public abstract List<WriteStatus> close();

hudi-client/hudi-client-common/src/main/java/org/apache/hudi/table/action/commit/HoodieMergeHelper.java

@@ -36,6 +36,7 @@
 import org.apache.hudi.internal.schema.convert.AvroInternalSchemaConverter;
 import org.apache.hudi.internal.schema.utils.AvroSchemaEvolutionUtils;
 import org.apache.hudi.internal.schema.utils.SerDeHelper;
+import org.apache.hudi.internal.schema.utils.InternalSchemaUtils;
 import org.apache.hudi.io.HoodieMergeHandle;
 import org.apache.hudi.io.storage.HoodieFileReader;
 import org.apache.hudi.io.storage.HoodieFileReaderFactory;
@@ -52,6 +53,8 @@
 import java.io.IOException;
 import java.util.Iterator;
 import java.util.List;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 public class HoodieMergeHelper<T extends HoodieRecordPayload> extends
@@ -93,6 +96,7 @@ public void runMerge(HoodieTable<T, HoodieData<HoodieRecord<T>>, HoodieData<Hood
 
     Option<InternalSchema> querySchemaOpt = SerDeHelper.fromJson(table.getConfig().getInternalSchema());
     boolean needToReWriteRecord = false;
+    Map<String, String> renameCols = new HashMap<>();
     // TODO support bootstrap
     if (querySchemaOpt.isPresent() && !baseFile.getBootstrapBaseFile().isPresent()) {
       // check implicitly add columns, and position reorder(spark sql may change cols order)
@@ -109,10 +113,14 @@ public void runMerge(HoodieTable<T, HoodieData<HoodieRecord<T>>, HoodieData<Hood
                       && writeInternalSchema.findIdByName(f) == querySchema.findIdByName(f)
                       && writeInternalSchema.findIdByName(f) != -1
                       && writeInternalSchema.findType(writeInternalSchema.findIdByName(f)).equals(querySchema.findType(writeInternalSchema.findIdByName(f)))).collect(Collectors.toList());
-      readSchema = AvroInternalSchemaConverter.convert(new InternalSchemaMerger(writeInternalSchema, querySchema, true, false).mergeSchema(), readSchema.getName());
+      readSchema = AvroInternalSchemaConverter
+          .convert(new InternalSchemaMerger(writeInternalSchema, querySchema, true, false, false).mergeSchema(), readSchema.getName());
       Schema writeSchemaFromFile = AvroInternalSchemaConverter.convert(writeInternalSchema, readSchema.getName());
       needToReWriteRecord = sameCols.size() != colNamesFromWriteSchema.size()
-              || SchemaCompatibility.checkReaderWriterCompatibility(writeSchemaFromFile, readSchema).getType() == org.apache.avro.SchemaCompatibility.SchemaCompatibilityType.COMPATIBLE;
+              || SchemaCompatibility.checkReaderWriterCompatibility(readSchema, writeSchemaFromFile).getType() == org.apache.avro.SchemaCompatibility.SchemaCompatibilityType.COMPATIBLE;
+      if (needToReWriteRecord) {
+        renameCols = InternalSchemaUtils.collectRenameCols(writeInternalSchema, querySchema);
+      }
     }
 
     try {
@@ -121,7 +129,7 @@ public void runMerge(HoodieTable<T, HoodieData<HoodieRecord<T>>, HoodieData<Hood
         readerIterator = getMergingIterator(table, mergeHandle, baseFile, reader, readSchema, externalSchemaTransformation);
       } else {
         if (needToReWriteRecord) {
-          readerIterator = HoodieAvroUtils.rewriteRecordWithNewSchema(reader.getRecordIterator(), readSchema);
+          readerIterator = HoodieAvroUtils.rewriteRecordWithNewSchema(reader.getRecordIterator(), readSchema, renameCols);
         } else {
           readerIterator = reader.getRecordIterator(readSchema);
         }

hudi-common/src/main/java/org/apache/hudi/avro/HoodieAvroUtils.java

@@ -70,6 +70,8 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Deque;
+import java.util.LinkedList;
 import java.util.TimeZone;
 import java.util.stream.Collectors;
 
@@ -405,6 +407,14 @@ public static GenericRecord rewriteRecordWithMetadata(GenericRecord genericRecor
     return newRecord;
   }
 
+  // TODO Unify the logical of rewriteRecordWithMetadata and rewriteEvolutionRecordWithMetadata, and delete this function.
+  public static GenericRecord rewriteEvolutionRecordWithMetadata(GenericRecord genericRecord, Schema newSchema, String fileName) {
+    GenericRecord newRecord = HoodieAvroUtils.rewriteRecordWithNewSchema(genericRecord, newSchema, new HashMap<>());
+    // do not preserve FILENAME_METADATA_FIELD
+    newRecord.put(HoodieRecord.FILENAME_METADATA_FIELD_POS, fileName);
+    return newRecord;
+  }
+
   /**
    * Converts list of {@link GenericRecord} provided into the {@link GenericRecord} adhering to the
    * provided {@code newSchema}.
@@ -719,14 +729,28 @@ public static Object getRecordColumnValues(HoodieRecord<? extends HoodieRecordPa
    *
    * @param oldRecord oldRecord to be rewritten
    * @param newSchema newSchema used to rewrite oldRecord
+   * @param renameCols a map store all rename cols, (k, v)-> (colNameFromNewSchema, colNameFromOldSchema)
    * @return newRecord for new Schema
    */
-  public static GenericRecord rewriteRecordWithNewSchema(IndexedRecord oldRecord, Schema newSchema) {
-    Object newRecord = rewriteRecordWithNewSchema(oldRecord, oldRecord.getSchema(), newSchema);
+  public static GenericRecord rewriteRecordWithNewSchema(IndexedRecord oldRecord, Schema newSchema, Map<String, String> renameCols) {
+    Object newRecord = rewriteRecordWithNewSchema(oldRecord, oldRecord.getSchema(), newSchema, renameCols, new LinkedList<>());
     return (GenericData.Record) newRecord;
   }
 
-  private static Object rewriteRecordWithNewSchema(Object oldRecord, Schema oldSchema, Schema newSchema) {
+  /**
+   * Given a avro record with a given schema, rewrites it into the new schema while setting fields only from the new schema.
+   * support deep rewrite for nested record and adjust rename operation.
+   * This particular method does the following things :
+   * a) Create a new empty GenericRecord with the new schema.
+   * b) For GenericRecord, copy over the data from the old schema to the new schema or set default values for all fields of this transformed schema
+   *
+   * @param oldRecord oldRecord to be rewritten
+   * @param newSchema newSchema used to rewrite oldRecord
+   * @param renameCols a map store all rename cols, (k, v)-> (colNameFromNewSchema, colNameFromOldSchema)
+   * @param fieldNames track the full name of visited field when we travel new schema.
+   * @return newRecord for new Schema
+   */
+  private static Object rewriteRecordWithNewSchema(Object oldRecord, Schema oldSchema, Schema newSchema, Map<String, String> renameCols, Deque<String> fieldNames) {
     if (oldRecord == null) {
       return null;
     }
@@ -741,10 +765,23 @@ private static Object rewriteRecordWithNewSchema(Object oldRecord, Schema oldSch
 
         for (int i = 0; i < fields.size(); i++) {
           Schema.Field field = fields.get(i);
+          String fieldName = field.name();
+          fieldNames.push(fieldName);
           if (oldSchema.getField(field.name()) != null) {
             Schema.Field oldField = oldSchema.getField(field.name());
-            helper.put(i, rewriteRecordWithNewSchema(indexedRecord.get(oldField.pos()), oldField.schema(), fields.get(i).schema()));
+            helper.put(i, rewriteRecordWithNewSchema(indexedRecord.get(oldField.pos()), oldField.schema(), fields.get(i).schema(), renameCols, fieldNames));
+          } else {
+            String fieldFullName = createFullName(fieldNames);
+            String[] colNamePartsFromOldSchema = renameCols.getOrDefault(fieldFullName, "").split("\\.");
+            String lastColNameFromOldSchema = colNamePartsFromOldSchema[colNamePartsFromOldSchema.length - 1];
+            // deal with rename
+            if (oldSchema.getField(field.name()) == null && oldSchema.getField(lastColNameFromOldSchema) != null) {
+              // find rename
+              Schema.Field oldField = oldSchema.getField(lastColNameFromOldSchema);
+              helper.put(i, rewriteRecordWithNewSchema(indexedRecord.get(oldField.pos()), oldField.schema(), fields.get(i).schema(), renameCols, fieldNames));
+            }
           }
+          fieldNames.pop();
         }
         GenericData.Record newRecord = new GenericData.Record(newSchema);
         for (int i = 0; i < fields.size(); i++) {
@@ -765,27 +802,41 @@ private static Object rewriteRecordWithNewSchema(Object oldRecord, Schema oldSch
         }
         Collection array = (Collection)oldRecord;
         List<Object> newArray = new ArrayList();
+        fieldNames.push("element");
         for (Object element : array) {
-          newArray.add(rewriteRecordWithNewSchema(element, oldSchema.getElementType(), newSchema.getElementType()));
+          newArray.add(rewriteRecordWithNewSchema(element, oldSchema.getElementType(), newSchema.getElementType(), renameCols, fieldNames));
         }
+        fieldNames.pop();
         return newArray;
       case MAP:
         if (!(oldRecord instanceof Map)) {
           throw new IllegalArgumentException("cannot rewrite record with different type");
         }
         Map<Object, Object> map = (Map<Object, Object>) oldRecord;
         Map<Object, Object> newMap = new HashMap<>();
+        fieldNames.push("value");
         for (Map.Entry<Object, Object> entry : map.entrySet()) {
-          newMap.put(entry.getKey(), rewriteRecordWithNewSchema(entry.getValue(), oldSchema.getValueType(), newSchema.getValueType()));
+          newMap.put(entry.getKey(), rewriteRecordWithNewSchema(entry.getValue(), oldSchema.getValueType(), newSchema.getValueType(), renameCols, fieldNames));
         }
+        fieldNames.pop();
         return newMap;
       case UNION:
-        return rewriteRecordWithNewSchema(oldRecord, getActualSchemaFromUnion(oldSchema, oldRecord), getActualSchemaFromUnion(newSchema, oldRecord));
+        return rewriteRecordWithNewSchema(oldRecord, getActualSchemaFromUnion(oldSchema, oldRecord), getActualSchemaFromUnion(newSchema, oldRecord), renameCols, fieldNames);
       default:
         return rewritePrimaryType(oldRecord, oldSchema, newSchema);
     }
   }
 
+  private static String createFullName(Deque<String> fieldNames) {
+    String result = "";
+    if (!fieldNames.isEmpty()) {
+      List<String> parentNames = new ArrayList<>();
+      fieldNames.descendingIterator().forEachRemaining(parentNames::add);
+      result = parentNames.stream().collect(Collectors.joining("."));
+    }
+    return result;
+  }
+
   private static Object rewritePrimaryType(Object oldValue, Schema oldSchema, Schema newSchema) {
     Schema realOldSchema = oldSchema;
     if (realOldSchema.getType() == UNION) {
@@ -958,9 +1009,10 @@ private static Schema getActualSchemaFromUnion(Schema schema, Object data) {
    *
    * @param oldRecords oldRecords to be rewrite
    * @param newSchema newSchema used to rewrite oldRecord
+   * @param renameCols a map store all rename cols, (k, v)-> (colNameFromNewSchema, colNameFromOldSchema)
    * @return a iterator of rewrote GeneriRcords
    */
-  public static Iterator<GenericRecord> rewriteRecordWithNewSchema(Iterator<GenericRecord> oldRecords, Schema newSchema) {
+  public static Iterator<GenericRecord> rewriteRecordWithNewSchema(Iterator<GenericRecord> oldRecords, Schema newSchema, Map<String, String> renameCols) {
     if (oldRecords == null || newSchema == null) {
       return Collections.emptyIterator();
     }
@@ -972,7 +1024,7 @@ public boolean hasNext() {
 
       @Override
       public GenericRecord next() {
-        return rewriteRecordWithNewSchema(oldRecords.next(), newSchema);
+        return rewriteRecordWithNewSchema(oldRecords.next(), newSchema, renameCols);
       }
     };
   }

hudi-common/src/main/java/org/apache/hudi/common/table/log/AbstractHoodieLogRecordReader.java

@@ -58,6 +58,7 @@
 import java.util.ArrayDeque;
 import java.util.Arrays;
 import java.util.Deque;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -379,7 +380,7 @@ private void processDataBlock(HoodieDataBlock dataBlock, Option<KeySpec> keySpec
       Option<Schema> schemaOption = getMergedSchema(dataBlock);
       while (recordIterator.hasNext()) {
         IndexedRecord currentRecord = recordIterator.next();
-        IndexedRecord record = schemaOption.isPresent() ? HoodieAvroUtils.rewriteRecordWithNewSchema(currentRecord, schemaOption.get()) : currentRecord;
+        IndexedRecord record = schemaOption.isPresent() ? HoodieAvroUtils.rewriteRecordWithNewSchema(currentRecord, schemaOption.get(), new HashMap<>()) : currentRecord;
         processNextRecord(createHoodieRecord(record, this.hoodieTableMetaClient.getTableConfig(), this.payloadClassFQN,
             this.preCombineField, this.withOperationField, this.simpleKeyGenFields, this.partitionName));
         totalLogRecords.incrementAndGet();

hudi-common/src/main/java/org/apache/hudi/internal/schema/action/InternalSchemaMerger.java

@@ -48,6 +48,25 @@ public class InternalSchemaMerger {
   // we can pass decimalType to reWriteRecordWithNewSchema directly, everything is ok.
   private boolean useColumnTypeFromFileSchema = true;
 
+  // deal with rename
+  // Whether to use column name from file schema to read files when we find some column name has changed.
+  // spark parquetReader need the original column name to read data, otherwise the parquetReader will read nothing.
+  // eg: current column name is colOldName, now we rename it to colNewName,
+  // we should not pass colNewName to parquetReader, we must pass colOldName to it; when we read out the data.
+  // for log reader
+  // since our reWriteRecordWithNewSchema function support rewrite directly, so we no need this parameter
+  // eg: current column name is colOldName, now we rename it to colNewName,
+  // we can pass colNewName to reWriteRecordWithNewSchema directly, everything is ok.
+  private boolean useColNameFromFileSchema = true;
+
+  public InternalSchemaMerger(InternalSchema fileSchema, InternalSchema querySchema, boolean ignoreRequiredAttribute, boolean useColumnTypeFromFileSchema, boolean useColNameFromFileSchema) {
+    this.fileSchema = fileSchema;
+    this.querySchema = querySchema;
+    this.ignoreRequiredAttribute = ignoreRequiredAttribute;
+    this.useColumnTypeFromFileSchema = useColumnTypeFromFileSchema;
+    this.useColNameFromFileSchema = useColNameFromFileSchema;
+  }
+
   public InternalSchemaMerger(InternalSchema fileSchema, InternalSchema querySchema, boolean ignoreRequiredAttribute, boolean useColumnTypeFromFileSchema) {
     this.fileSchema = fileSchema;
     this.querySchema = querySchema;
@@ -131,12 +150,15 @@ private List<Types.Field> buildRecordType(List<Types.Field> oldFields, List<Type
   private Types.Field dealWithRename(int fieldId, Type newType, Types.Field oldField) {
     Types.Field fieldFromFileSchema = fileSchema.findField(fieldId);
     String nameFromFileSchema = fieldFromFileSchema.name();
+    String nameFromQuerySchema = querySchema.findField(fieldId).name();
     Type typeFromFileSchema = fieldFromFileSchema.type();
     // Current design mechanism guarantees nestedType change is not allowed, so no need to consider.
     if (newType.isNestedType()) {
-      return Types.Field.get(oldField.fieldId(), oldField.isOptional(), nameFromFileSchema, newType, oldField.doc());
+      return Types.Field.get(oldField.fieldId(), oldField.isOptional(),
+          useColNameFromFileSchema ? nameFromFileSchema : nameFromQuerySchema, newType, oldField.doc());
     } else {
-      return Types.Field.get(oldField.fieldId(), oldField.isOptional(), nameFromFileSchema, useColumnTypeFromFileSchema ? typeFromFileSchema : newType, oldField.doc());
+      return Types.Field.get(oldField.fieldId(), oldField.isOptional(),
+          useColNameFromFileSchema ? nameFromFileSchema : nameFromQuerySchema, useColumnTypeFromFileSchema ? typeFromFileSchema : newType, oldField.doc());
     }
   }
 

hudi-common/src/main/java/org/apache/hudi/internal/schema/utils/InternalSchemaUtils.java

@@ -267,4 +267,20 @@ public static String createFullName(String name, Deque<String> fieldNames) {
     }
     return result;
   }
+
+  /**
+   * Try to find all renamed cols between oldSchema and newSchema.
+   *
+   * @param oldSchema oldSchema
+   * @param newSchema newSchema which modified from oldSchema
+   * @return renameCols Map. (k, v) -> (colNameFromNewSchema, colNameFromOldSchema)
+   */
+  public static Map<String, String> collectRenameCols(InternalSchema oldSchema, InternalSchema newSchema) {
+    List<String> colNamesFromWriteSchema = oldSchema.getAllColsFullName();
+    return colNamesFromWriteSchema.stream().filter(f -> {
+      int filedIdFromWriteSchema = oldSchema.findIdByName(f);
+      // try to find the cols which has the same id, but have different colName;
+      return newSchema.getAllIds().contains(filedIdFromWriteSchema) && !newSchema.findfullName(filedIdFromWriteSchema).equalsIgnoreCase(f);
+    }).collect(Collectors.toMap(e -> newSchema.findfullName(oldSchema.findIdByName(e)), e -> e));
+  }
 }

hudi-common/src/test/java/org/apache/hudi/internal/schema/utils/TestAvroSchemaEvolutionUtils.java

@@ -284,7 +284,7 @@ public void testReWriteRecordWithTypeChanged() {
         .updateColumnType("col6", Types.StringType.get());
     InternalSchema newSchema = SchemaChangeUtils.applyTableChanges2Schema(internalSchema, updateChange);
     Schema newAvroSchema = AvroInternalSchemaConverter.convert(newSchema, avroSchema.getName());
-    GenericRecord newRecord = HoodieAvroUtils.rewriteRecordWithNewSchema(avroRecord, newAvroSchema);
+    GenericRecord newRecord = HoodieAvroUtils.rewriteRecordWithNewSchema(avroRecord, newAvroSchema, new HashMap<>());
 
     Assertions.assertEquals(GenericData.get().validate(newAvroSchema, newRecord), true);
   }
@@ -349,7 +349,7 @@ public void testReWriteNestRecord() {
     );
 
     Schema newAvroSchema = AvroInternalSchemaConverter.convert(newRecord, schema.getName());
-    GenericRecord newAvroRecord = HoodieAvroUtils.rewriteRecordWithNewSchema(avroRecord, newAvroSchema);
+    GenericRecord newAvroRecord = HoodieAvroUtils.rewriteRecordWithNewSchema(avroRecord, newAvroSchema, new HashMap<>());
     // test the correctly of rewrite
     Assertions.assertEquals(GenericData.get().validate(newAvroSchema, newAvroRecord), true);
   }