Message Format

CloudCanal supports selecting the synchronized message store format with MQ, this article introduces the definition and description of multiple message formats of MQ, which facilitates downstream consumption and use.

Message format introduction

Supported message synchronization formats

CloudCanal Json: CloudCanal's default message format, parsing incremental logs from the database and transmitting to Kafka, supporting batch message transmission.
Canal Json: A compatible format for Canal, data stored in the Canal Json format.
Aliyun DTS Avro: An data serialization format that can transform data structures or objects into a format suitable for storage or transmission.
Debezium Envelope: Debezium official CDC message format, carrying SCHEMA information, friendly to large data downstream consumption.

Target end MQ support

Message format	Kafka	RocketMQ	RabbitMQ
CloudCanal Json	Supported	Supported	Supported
Canal Json	Supported	Supported	Supported
Aliyun DTS Avro	Supported	-	-
Debezium Envelope	Supported	-	-

Source end MQ support

Message format	Kafka	RocketMQ	RabbitMQ
CloudCanal Json	Supported	Supported	Supported
Canal Json	Supported	Supported	Supported
Aliyun DTS Avro	-	-	-
Debezium Envelope	-	-	-

Message format details

CloudCanal Json

Parameter description:

Parameter	Type	Description
action	String	The type of operation, such as: INSERT / UPDATE / DELETE.
bid	Long	BatchEventBuffer's Batch Id.
before	List	The data before the change.
data	List	The current operation data.
db	String	Database name.
schema	String	SCHEMA name.
table	String	Table name.
dbValType	Map	The field data type name.
jdbcType	Map	The field JDBC data type.
entryType	String	The source event type, such as: ROWDATA / TRANSACTIONEND.
isDdl	Boolean	Whether it is a DDL operation.
pks	List	The primary key names of the source end.
execTs	Long	The time of source end SQL execution, a 13-digit Unix timestamp in milliseconds.
sendTs	Long	The time of operation transmission, 13 digit Unix timestamp in milliseconds.
sql	String	The DDL statement executed at the source end.
tableChanges	Json	When this message is a DDL, it carries the metadata of this table, such as: primary key, column.

DML operation example is as follows:

{
    "action":"INSERT/DELETE/UPDATE",
    "before":[
      // The before field of an UPDATE statement.
      {
        "col1":"22",
        "col2":"22",
        "col_pk":"22"
      }
    ],
    "bid":0,
    "data":[
      {
        "col1":"11",
        "col2":"11",
        "col_pk":"11"
      }
    ],
    "db":"db_test",
    "dbValType":{
        "col1":"varchar(22)",
        "col2":"varchar(22)",
        "col_pk":"varchar(22)"
    },
    "isDdl":false,
    "entryType":"ROWDATA",
    "execTs":1669789152000,
    "jdbcType":{
        "col1":12,
        "col2":12,
        "col_pk":12
    },
    "pks":[],
    "schema":"db_test",
    "sendTs":1669789153377,
    "sql":"",
    "table":"table_test"
}

DDL operation example is as follows:

{
    "action":"ALTER",
    "before":[],
    "bid":0,
    "data":[],
    "db":"db_test",
    "dbValType":{
        "col1":"varchar(22)",
        "col2":"varchar(22)",
        "col_pk":"varchar(22)"
    },
    "isDdl":true,
    "entryType":"ROWDATA",
    "execTs":1669789188000,
    "jdbcType":{
        "col1":12,
        "col2":12,
        "col_pk":12
    },
    "pks":[],
    "schema":"db_test",
    "sendTs":1669789189533,
    "sql":"alter table table_test add col2 varchar(22) null",
    "table":"table_test",
    "tableChanges":{
        "table":{
            "columns":[
                {
                    "jdbcType":12, // Jdbc type.
                    "name":"col1",    // Column name.
                    "position":0,  // Column order.
                    "typeExpression":"varchar(22)", // Type annotation.
                    "typeName":"varchar" // Type name.
                },
                {
                    "jdbcType":12,
                    "name":"col2",
                    "position":1, 
                    "typeExpression":"varchar(22)", 
                    "typeName":"varchar" 
                },
                {
                    "jdbcType":12, 
                    "name":"col_pk",   
                    "position":2,  
                    "typeExpression":"varchar(22)", 
                    "typeName":"varchar" 
                }
            ],
            "primaryKeyColumnNames":["col_pk"] // The name list of primary key.
        },
        "type":"ALTER"
    }
}

Canal Json

Parameter description:

Parameter	Type	Description
type	String	The operation type, e.g.: INSERT / UPDATE / DELETE.
id	Long	The sequence number of the operation.
old	List	The data before the change.
data	List	The data of the current operation.
database	String	The database name.
table	String	The table name.
mysqlType	Map	The field data type names.
sqlType	Map	The field JDBC data types.
isDdl	Boolean	Whether it is a DDL operation.
pkNames	List	The primary key names of the source end.
es	Long	The time of the SQL execution at the source end, Unix timestamp in milliseconds.
ts	Long	The time when the operation was sent, Unix timestamp in milliseconds.
sql	String	The DDL statement executed at the source end.
tableChanges	Json	When the message is a DDL, it carries the meta information of the table, such as primary key and columns.

DML operation example is as follows:

{
    "data":[
      {
        "col1":"11",
        "col2":"11",
        "col_pk":"11"
      }
    ],
    "database":"db_test",
    "es":1669790847000,
    "id":0,
    "isDdl":false,
    "mysqlType":{
        "col1":"varchar(22)",
        "col2":"varchar(22)",
        "col_pk":"varchar(22)"
    },
    "old":[
      // The old field for an UPDATE type.
      {
        "col1":"22",
        "col2":"22",
        "col_pk":"22"
      }
    ],
    "pkNames":["col_pk"],
    "sql":"",
    "sqlType":{
        "col1":12,
        "col2":12,
        "col_pk":12
    },
    "table":"table_test",
    "ts":1669790848072,
    "type":"INSERT/DELETE/UPDATE"
}

DDL operation example is as follows:

{
    "data":[],
    "database":"db_test",
    "es":1669790951000,
    "id":0,
    "isDdl":true,
    "mysqlType":{
        "col1":"varchar(22)",
        "col2":"varchar(22)",
        "col_pk":"varchar(22)"
    },
    "old":[],
    "pkNames":[],
    "sql":"alter table table_test add col2 varchar(22) null",
    "sqlType":{
        "col1":12,
        "col2":12,
        "col_pk":12
    },
    "table":"table_test",
    "tableChanges":{
        "table":{
            "columns":[
                {
                    "jdbcType":12, // Jdbc type.
                    "name":"col1", // Column name.
                    "position":0,  // Column order.
                    "typeExpression":"varchar(22)", // Type annotation.
                    "typeName":"varchar" // Type name.
                },
                {
                    "jdbcType":12,
                    "name":"col2",
                    "position":1,
                    "typeExpression":"varchar(22)",
                    "typeName":"varchar"
                },
                {
                    "jdbcType":12,
                    "name":"col_pk",
                    "position":2,
                    "typeExpression":"varchar(22)",
                    "typeName":"varchar"
                }
            ],
            "primaryKeyColumnNames":["col_pk"] // The name list of primary key.
        },
        "type":"ALTER"
    },
    "ts":1669790952584,
    "type":"ALTER"
}

Alibaba DTS Avro

This message type requires data parsing according to the SCHEMA definition of DTS Avro. Refer to the DTS Avro's SCHEMA definition for more information on DTS Avro.

Debezium Envelope

This message type mainly consists of SCHEMA and PAYLOAD, the SCHEMA is the metadata of the data, and the PAYLOAD contains the content that changes the records.
Refer to the Official Debezium documentation for details on the SCHEMA definition.

Parameter description:

Parameter	Type	Description
op	String	The type of operation, e.g.: c(INSERT), u(UPDATE), d(DELETE), a(ALTER).
ts_ms	Long	The time the operation was sent, a 13 digit Unix timestamp in milliseconds.
after	Json	The data before the change.
before	Json	The data after the change.
source	Json	Meta information of the event, e.g.: db,table.
ddl	String	The DDL statement executed at the source.
tableChanges	Json	The table metadata like: primary key, columns, carried by the message in case of DDL.

DML operation example is as follows:

{
  "schema":...,
  "payload":{
    "op":"i",
    "ts_ms":1669796261933,
    "after":{
      "col1":"11",
      "col2":"11",
      "col_pk":"11"
    },
    "before":{},
    "source":{
      "ts_ms":1669796261933,
      "db":"db_test",
      "table":"table_test",
      "connector":"MySQL",
      "gtid": null,
      "file": "mysql-bin.000003",
      "pos": 154,
      "server_id": 223344,
      ...
    }
  }
}

DDL operation example is as follows:

{
  "schema":...,
  "payload":{
    "databaseName":"db_test",
    "ddl":"alter table table_test add col2 varchar(22) null",
    "ts_ms":1669797213247,
    "source":{
      "ts_ms":1669796261933,
      "db":"db_test",
      "table":"table_test",
      "connector":"MySQL",
      "gtid": null,
      "file": "mysql-bin.000003",
      "pos": 154,
      "server_id": 223344,
      ...
    },
    "tableChanges":{
      "type":"ALTER",
      "table":{
        "columns":[
          {
            "jdbcType":12, // Jdbc type.
            "name":"col1", // Column name.
            "position":0,  // Column order.
            "typeExpression":"varchar(22)", // Type annotation.
            "typeName":"varchar" // Type name.
          },
          {
            "jdbcType":12,
            "name":"col2",
            "position":1,
            "typeExpression":"varchar(22)",
            "typeName":"varchar"
          },
          {
            "jdbcType":12,
            "name":"col_pk",
            "position":2,
            "typeExpression":"varchar(22)",
            "typeName":"varchar"
          }
        ],
        "primaryKeyColumnNames":["col_pk"], // The name list of primary key.
      }
    }
  }
}

Message format introduction​

Supported message synchronization formats​

Target end MQ support​

Source end MQ support​

Message format details​

CloudCanal Json​

Canal Json​

Alibaba DTS Avro​

Debezium Envelope​

Message format introduction

Supported message synchronization formats

Target end MQ support

Source end MQ support

Message format details

CloudCanal Json

Canal Json

Alibaba DTS Avro

Debezium Envelope