[HUDI-3478][HUDI-4887] Use Avro as the format of persisted cdc data

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

@@ -102,16 +102,11 @@ public HoodieCDCLogger(
       this.cdcSupplementalLoggingMode = HoodieCDCSupplementalLoggingMode.parse(
           config.getStringOrDefault(HoodieTableConfig.CDC_SUPPLEMENTAL_LOGGING_MODE));
 
-      if (cdcSupplementalLoggingMode.equals(HoodieCDCSupplementalLoggingMode.WITH_BEFORE_AFTER)) {
-        this.cdcSchema = HoodieCDCUtils.CDC_SCHEMA;
-        this.cdcSchemaString = HoodieCDCUtils.CDC_SCHEMA_STRING;
-      } else if (cdcSupplementalLoggingMode.equals(HoodieCDCSupplementalLoggingMode.WITH_BEFORE)) {
-        this.cdcSchema = HoodieCDCUtils.CDC_SCHEMA_OP_RECORDKEY_BEFORE;
-        this.cdcSchemaString = HoodieCDCUtils.CDC_SCHEMA_OP_RECORDKEY_BEFORE_STRING;
-      } else {
-        this.cdcSchema = HoodieCDCUtils.CDC_SCHEMA_OP_AND_RECORDKEY;
-        this.cdcSchemaString = HoodieCDCUtils.CDC_SCHEMA_OP_AND_RECORDKEY_STRING;
-      }
+      this.cdcSchema = HoodieCDCUtils.schemaBySupplementalLoggingMode(
+          cdcSupplementalLoggingMode,
+          dataSchema
+      );
+      this.cdcSchemaString = this.cdcSchema.toString();
 
       this.cdcData = new ExternalSpillableMap<>(
           maxInMemorySizeInBytes,
@@ -158,18 +153,21 @@ private GenericData.Record createCDCRecord(HoodieCDCOperation operation,
                                              GenericRecord newRecord) {
     GenericData.Record record;
     if (cdcSupplementalLoggingMode.equals(HoodieCDCSupplementalLoggingMode.WITH_BEFORE_AFTER)) {
-      record = HoodieCDCUtils.cdcRecord(operation.getValue(), commitTime,
+      record = HoodieCDCUtils.cdcRecord(cdcSchema, operation.getValue(), commitTime,
           removeCommitMetadata(oldRecord), newRecord);
     } else if (cdcSupplementalLoggingMode.equals(HoodieCDCSupplementalLoggingMode.WITH_BEFORE)) {
-      record = HoodieCDCUtils.cdcRecord(operation.getValue(), recordKey,
+      record = HoodieCDCUtils.cdcRecord(cdcSchema, operation.getValue(), recordKey,
           removeCommitMetadata(oldRecord));
     } else {
-      record = HoodieCDCUtils.cdcRecord(operation.getValue(), recordKey);
+      record = HoodieCDCUtils.cdcRecord(cdcSchema, operation.getValue(), recordKey);
     }
     return record;
   }
 
   private GenericRecord removeCommitMetadata(GenericRecord record) {
+    if (record == null) {
+      return null;
+    }
     return HoodieAvroUtils.rewriteRecordWithNewSchema(record, dataSchema, new HashMap<>());
   }
 
@@ -221,18 +219,6 @@ public void close() {
     }
   }
 
-  public static Option<AppendResult> writeCDCDataIfNeeded(HoodieCDCLogger cdcLogger,
-                                                          long recordsWritten,
-                                                          long insertRecordsWritten) {
-    if (cdcLogger == null || recordsWritten == 0L || (recordsWritten == insertRecordsWritten)) {
-      // the following cases where we do not need to write out the cdc file:
-      // case 1: all the data from the previous file slice are deleted. and no new data is inserted;
-      // case 2: all the data are new-coming,
-      return Option.empty();
-    }
-    return cdcLogger.writeCDCData();
-  }
-
   public static void setCDCStatIfNeeded(HoodieWriteStat stat,
                                         Option<AppendResult> cdcResult,
                                         String partitionPath,

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

@@ -425,6 +425,16 @@ protected void writeIncomingRecords() throws IOException {
     }
   }
 
+  private Option<AppendResult> writeCDCDataIfNeeded() {
+    if (cdcLogger == null || recordsWritten == 0L || (recordsWritten == insertRecordsWritten)) {
+      // the following cases where we do not need to write out the cdc file:
+      // case 1: all the data from the previous file slice are deleted. and no new data is inserted;
+      // case 2: all the data are new-coming,
+      return Option.empty();
+    }
+    return cdcLogger.writeCDCData();
+  }
+
   @Override
   public List<WriteStatus> close() {
     try {
@@ -445,8 +455,7 @@ public List<WriteStatus> close() {
       }
 
       // if there are cdc data written, set the CDC-related information.
-      Option<AppendResult> cdcResult =
-          HoodieCDCLogger.writeCDCDataIfNeeded(cdcLogger, recordsWritten, insertRecordsWritten);
+      Option<AppendResult> cdcResult = writeCDCDataIfNeeded();
       HoodieCDCLogger.setCDCStatIfNeeded(stat, cdcResult, partitionPath, fs);
 
       long fileSizeInBytes = FSUtils.getFileSize(fs, newFilePath);

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

@@ -109,6 +109,11 @@ public static Schema createNullableSchema(Schema.Type avroType) {
     return Schema.createUnion(Schema.create(Schema.Type.NULL), Schema.create(avroType));
   }
 
+  public static Schema createNullableSchema(Schema schema) {
+    checkState(schema.getType() != Schema.Type.NULL);
+    return Schema.createUnion(Schema.create(Schema.Type.NULL), schema);
+  }
+
   /**
    * Returns true in case when schema contains the field w/ provided name
    */

hudi-common/src/main/java/org/apache/hudi/common/table/cdc/HoodieCDCUtils.java

@@ -18,12 +18,17 @@
 
 package org.apache.hudi.common.table.cdc;
 
+import org.apache.avro.JsonProperties;
 import org.apache.avro.Schema;
 import org.apache.avro.generic.GenericData;
 import org.apache.avro.generic.GenericRecord;
 
+import org.apache.hudi.avro.AvroSchemaUtils;
 import org.apache.hudi.exception.HoodieException;
 
+import java.util.Arrays;
+import java.util.List;
+
 public class HoodieCDCUtils {
 
   public static final String CDC_LOGFILE_SUFFIX = "-cdc";
@@ -50,33 +55,6 @@ public class HoodieCDCUtils {
       CDC_AFTER_IMAGE
   };
 
-  /**
-   * This is the standard CDC output format.
-   * Also, this is the schema of cdc log file in the case `hoodie.table.cdc.supplemental.logging.mode` is 'cdc_data_before_after'.
-   */
-  public static final String CDC_SCHEMA_STRING = "{\"type\":\"record\",\"name\":\"Record\","
-      + "\"fields\":["
-      + "{\"name\":\"op\",\"type\":[\"string\",\"null\"]},"
-      + "{\"name\":\"ts_ms\",\"type\":[\"string\",\"null\"]},"
-      + "{\"name\":\"before\",\"type\":[\"string\",\"null\"]},"
-      + "{\"name\":\"after\",\"type\":[\"string\",\"null\"]}"
-      + "]}";
-
-  public static final Schema CDC_SCHEMA = new Schema.Parser().parse(CDC_SCHEMA_STRING);
-
-  /**
-   * The schema of cdc log file in the case `hoodie.table.cdc.supplemental.logging.mode` is 'cdc_data_before'.
-   */
-  public static final String CDC_SCHEMA_OP_RECORDKEY_BEFORE_STRING = "{\"type\":\"record\",\"name\":\"Record\","
-      + "\"fields\":["
-      + "{\"name\":\"op\",\"type\":[\"string\",\"null\"]},"
-      + "{\"name\":\"record_key\",\"type\":[\"string\",\"null\"]},"
-      + "{\"name\":\"before\",\"type\":[\"string\",\"null\"]}"
-      + "]}";
-
-  public static final Schema CDC_SCHEMA_OP_RECORDKEY_BEFORE =
-      new Schema.Parser().parse(CDC_SCHEMA_OP_RECORDKEY_BEFORE_STRING);
-
   /**
    * The schema of cdc log file in the case `hoodie.table.cdc.supplemental.logging.mode` is 'cdc_op_key'.
    */
@@ -89,32 +67,50 @@ public class HoodieCDCUtils {
   public static final Schema CDC_SCHEMA_OP_AND_RECORDKEY =
       new Schema.Parser().parse(CDC_SCHEMA_OP_AND_RECORDKEY_STRING);
 
-  public static final Schema schemaBySupplementalLoggingMode(HoodieCDCSupplementalLoggingMode supplementalLoggingMode) {
-    switch (supplementalLoggingMode) {
-      case WITH_BEFORE_AFTER:
-        return CDC_SCHEMA;
-      case WITH_BEFORE:
-        return CDC_SCHEMA_OP_RECORDKEY_BEFORE;
-      case OP_KEY:
-        return CDC_SCHEMA_OP_AND_RECORDKEY;
-      default:
-        throw new HoodieException("not support this supplemental logging mode: " + supplementalLoggingMode);
+  public static Schema schemaBySupplementalLoggingMode(
+      HoodieCDCSupplementalLoggingMode supplementalLoggingMode,
+      Schema tableSchema) {
+    if (supplementalLoggingMode == HoodieCDCSupplementalLoggingMode.OP_KEY) {
+      return CDC_SCHEMA_OP_AND_RECORDKEY;
+    } else if (supplementalLoggingMode == HoodieCDCSupplementalLoggingMode.WITH_BEFORE) {
+      return createCDCSchema(tableSchema, false);
+    } else if (supplementalLoggingMode == HoodieCDCSupplementalLoggingMode.WITH_BEFORE_AFTER) {
+      return createCDCSchema(tableSchema, true);
+    } else {
+      throw new HoodieException("not support this supplemental logging mode: " + supplementalLoggingMode);
     }
   }
 
+  private static Schema createCDCSchema(Schema tableSchema, boolean withAfterImage) {
+    Schema imageSchema = AvroSchemaUtils.createNullableSchema(tableSchema);
+    Schema.Field opField = new Schema.Field(CDC_OPERATION_TYPE,
+        AvroSchemaUtils.createNullableSchema(Schema.Type.STRING), "", JsonProperties.NULL_VALUE);
+    Schema.Field beforeField = new Schema.Field(
+        CDC_BEFORE_IMAGE, imageSchema, "", JsonProperties.NULL_VALUE);
+    List<Schema.Field> fields;
+    if (withAfterImage) {
+      Schema.Field tsField = new Schema.Field(CDC_COMMIT_TIMESTAMP,
+          AvroSchemaUtils.createNullableSchema(Schema.Type.STRING), "", JsonProperties.NULL_VALUE);
+      Schema.Field afterField = new Schema.Field(
+          CDC_AFTER_IMAGE, imageSchema, "", JsonProperties.NULL_VALUE);
+      fields = Arrays.asList(opField, tsField, beforeField, afterField);
+    } else {
+      Schema.Field keyField = new Schema.Field(CDC_RECORD_KEY,
+          AvroSchemaUtils.createNullableSchema(Schema.Type.STRING), "", JsonProperties.NULL_VALUE);
+      fields = Arrays.asList(opField, keyField, beforeField);
+    }
+
+    Schema mergedSchema = Schema.createRecord("CDC", null, tableSchema.getNamespace(), false);
+    mergedSchema.setFields(fields);
+    return mergedSchema;
+  }
+
   /**
    * Build the cdc record which has all the cdc fields when `hoodie.table.cdc.supplemental.logging.mode` is 'cdc_data_before_after'.
    */
-  public static GenericData.Record cdcRecord(
-      String op, String commitTime, GenericRecord before, GenericRecord after) {
-    String beforeJsonStr = recordToJson(before);
-    String afterJsonStr = recordToJson(after);
-    return cdcRecord(op, commitTime, beforeJsonStr, afterJsonStr);
-  }
-
-  public static GenericData.Record cdcRecord(
-      String op, String commitTime, String before, String after) {
-    GenericData.Record record = new GenericData.Record(CDC_SCHEMA);
+  public static GenericData.Record cdcRecord(Schema cdcSchema, String op, String commitTime,
+                                             GenericRecord before, GenericRecord after) {
+    GenericData.Record record = new GenericData.Record(cdcSchema);
     record.put(CDC_OPERATION_TYPE, op);
     record.put(CDC_COMMIT_TIMESTAMP, commitTime);
     record.put(CDC_BEFORE_IMAGE, before);
@@ -125,20 +121,20 @@ public static GenericData.Record cdcRecord(
   /**
    * Build the cdc record when `hoodie.table.cdc.supplemental.logging.mode` is 'cdc_data_before'.
    */
-  public static GenericData.Record cdcRecord(String op, String recordKey, GenericRecord before) {
-    GenericData.Record record = new GenericData.Record(CDC_SCHEMA_OP_RECORDKEY_BEFORE);
+  public static GenericData.Record cdcRecord(Schema cdcSchema, String op,
+                                             String recordKey, GenericRecord before) {
+    GenericData.Record record = new GenericData.Record(cdcSchema);
     record.put(CDC_OPERATION_TYPE, op);
     record.put(CDC_RECORD_KEY, recordKey);
-    String beforeJsonStr = recordToJson(before);
-    record.put(CDC_BEFORE_IMAGE, beforeJsonStr);
+    record.put(CDC_BEFORE_IMAGE, before);
     return record;
   }
 
   /**
    * Build the cdc record when `hoodie.table.cdc.supplemental.logging.mode` is 'cdc_op_key'.
    */
-  public static GenericData.Record cdcRecord(String op, String recordKey) {
-    GenericData.Record record = new GenericData.Record(CDC_SCHEMA_OP_AND_RECORDKEY);
+  public static GenericData.Record cdcRecord(Schema cdcSchema, String op, String recordKey) {
+    GenericData.Record record = new GenericData.Record(cdcSchema);
     record.put(CDC_OPERATION_TYPE, op);
     record.put(CDC_RECORD_KEY, recordKey);
     return record;

hudi-common/src/test/java/org/apache/hudi/common/functional/TestHoodieLogFormat.java

@@ -19,6 +19,7 @@
 package org.apache.hudi.common.functional;
 
 import org.apache.avro.Schema;
+import org.apache.avro.generic.GenericData;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.generic.IndexedRecord;
 
@@ -37,6 +38,7 @@
 import org.apache.hudi.common.model.HoodieLogFile;
 import org.apache.hudi.common.model.HoodieRecord;
 import org.apache.hudi.common.model.HoodieTableType;
+import org.apache.hudi.common.table.cdc.HoodieCDCSupplementalLoggingMode;
 import org.apache.hudi.common.table.cdc.HoodieCDCUtils;
 import org.apache.hudi.common.table.log.AppendResult;
 import org.apache.hudi.common.table.log.HoodieLogFileReader;
@@ -561,46 +563,79 @@ public void testCDCBlock() throws IOException, InterruptedException {
         .withFs(fs)
         .build();
 
-    GenericRecord record1 = HoodieCDCUtils.cdcRecord("i", "100",
-        null, "{\"uuid\": 1, \"name\": \"apple\"}, \"ts\": 1100}");
-    GenericRecord record2 = HoodieCDCUtils.cdcRecord("u", "100",
-        "{\"uuid\": 2, \"name\": \"banana\"}, \"ts\": 1000}",
-        "{\"uuid\": 2, \"name\": \"blueberry\"}, \"ts\": 1100}");
-    GenericRecord record3 = HoodieCDCUtils.cdcRecord("d", "100",
-        "{\"uuid\": 3, \"name\": \"cherry\"}, \"ts\": 1000}", null);
+    String dataSchameString = "{\"type\":\"record\",\"name\":\"Record\","
+        + "\"fields\":["
+        + "{\"name\":\"uuid\",\"type\":[\"int\",\"null\"]},"
+        + "{\"name\":\"name\",\"type\":[\"string\",\"null\"]},"
+        + "{\"name\":\"ts\",\"type\":[\"long\",\"null\"]}"
+        + "]}";
+    Schema dataSchema = new Schema.Parser().parse(dataSchameString);
+    Schema cdcSchema = HoodieCDCUtils.schemaBySupplementalLoggingMode(
+        HoodieCDCSupplementalLoggingMode.WITH_BEFORE_AFTER, dataSchema);
+    GenericRecord insertedRecord = new GenericData.Record(dataSchema);
+    insertedRecord.put("uuid", 1);
+    insertedRecord.put("name", "apple");
+    insertedRecord.put("ts", 1100L);
+
+    GenericRecord updateBeforeImageRecord = new GenericData.Record(dataSchema);
+    updateBeforeImageRecord.put("uuid", 2);
+    updateBeforeImageRecord.put("name", "banana");
+    updateBeforeImageRecord.put("ts", 1000L);
+    GenericRecord updateAfterImageRecord = new GenericData.Record(dataSchema);
+    updateAfterImageRecord.put("uuid", 2);
+    updateAfterImageRecord.put("name", "blueberry");
+    updateAfterImageRecord.put("ts", 1100L);
+
+    GenericRecord deletedRecord = new GenericData.Record(dataSchema);
+    deletedRecord.put("uuid", 3);
+    deletedRecord.put("name", "cherry");
+    deletedRecord.put("ts", 1000L);
+
+    GenericRecord record1 = HoodieCDCUtils.cdcRecord(cdcSchema, "i", "100",
+        null, insertedRecord);
+    GenericRecord record2 = HoodieCDCUtils.cdcRecord(cdcSchema, "u", "100",
+        updateBeforeImageRecord, updateAfterImageRecord);
+    GenericRecord record3 = HoodieCDCUtils.cdcRecord(cdcSchema, "d", "100",
+        deletedRecord, null);
     List<IndexedRecord> records = new ArrayList<>(Arrays.asList(record1, record2, record3));
     Map<HoodieLogBlock.HeaderMetadataType, String> header = new HashMap<>();
     header.put(HoodieLogBlock.HeaderMetadataType.INSTANT_TIME, "100");
-    header.put(HoodieLogBlock.HeaderMetadataType.SCHEMA, HoodieCDCUtils.CDC_SCHEMA_STRING);
+    header.put(HoodieLogBlock.HeaderMetadataType.SCHEMA, cdcSchema.toString());
     HoodieDataBlock dataBlock = getDataBlock(HoodieLogBlockType.CDC_DATA_BLOCK, records, header);
     writer.appendBlock(dataBlock);
     writer.close();
 
-    Reader reader = HoodieLogFormat.newReader(fs, writer.getLogFile(), HoodieCDCUtils.CDC_SCHEMA);
+    Reader reader = HoodieLogFormat.newReader(fs, writer.getLogFile(), cdcSchema);
     assertTrue(reader.hasNext());
     HoodieLogBlock block = reader.next();
     HoodieDataBlock dataBlockRead = (HoodieDataBlock) block;
     List<IndexedRecord> recordsRead = getRecords(dataBlockRead);
     assertEquals(3, recordsRead.size(),
         "Read records size should be equal to the written records size");
-    assertEquals(dataBlockRead.getSchema(), HoodieCDCUtils.CDC_SCHEMA);
+    assertEquals(dataBlockRead.getSchema(), cdcSchema);
 
     GenericRecord insert = (GenericRecord) recordsRead.stream()
         .filter(record -> record.get(0).toString().equals("i")).findFirst().get();
     assertNull(insert.get("before"));
     assertNotNull(insert.get("after"));
+    assertEquals(((GenericRecord) insert.get("after")).get("name").toString(), "apple");
 
     GenericRecord update = (GenericRecord) recordsRead.stream()
         .filter(record -> record.get(0).toString().equals("u")).findFirst().get();
     assertNotNull(update.get("before"));
     assertNotNull(update.get("after"));
-    assertTrue(update.get("before").toString().contains("banana"));
-    assertTrue(update.get("after").toString().contains("blueberry"));
+    GenericRecord uBefore = (GenericRecord) update.get("before");
+    GenericRecord uAfter = (GenericRecord) update.get("after");
+    assertEquals(String.valueOf(uBefore.get("name")), "banana");
+    assertEquals(Long.valueOf(uBefore.get("ts").toString()), 1000L);
+    assertEquals(String.valueOf(uAfter.get("name")), "blueberry");
+    assertEquals(Long.valueOf(uAfter.get("ts").toString()), 1100L);
 
     GenericRecord delete = (GenericRecord) recordsRead.stream()
         .filter(record -> record.get(0).toString().equals("d")).findFirst().get();
     assertNotNull(delete.get("before"));
     assertNull(delete.get("after"));
+    assertEquals(((GenericRecord) delete.get("before")).get("name").toString(), "cherry");
 
     reader.close();
   }