Data subscription helps you get incremental data from TencentDB for MariaDB and TDSQL, so that you can flexibly process real-time incremental data based on your actual business needs.

Feature List

• Data subscription is supported for TencentDB for MariaDB and TDSQL instances in public cloud.
• Data subscription is supported for TencentDB for MariaDB and TDSQL instances in private cloud.

Data Source Type

TencentDB for MariaDB and TDSQL.

Message Format

The data subscription feature parses instance binlogs (in row format), encapsulates binlog events into messages in JSON format, and uploads them to a Kafka cluster. Message types include DML, GTID, XID, and QUERY events, which represent modification to data rows, start of transactions, commit of transactions, and DDL statements, respectively. DML events include insert, update, and delete events.

The message format of a DML event is as follows:

{
    "logtype":"mysqlbinlog",          // Log type. The value is unique and must be `mysqlbinlog`
    "eventtype":23,                   // Event type code of a binlog in MySQL

    "eventtypestr":"insert",          / *Event type string. The value can be `insert`, `update`, `delete`, `gtid`, `xid`, or `query`.
                                        An `insert`, `update`, or `delete` event indicates `DML` statements; a `tid` event indicates start of a transaction;
                                        An `xid` event indicates end of a transaction; a `query` event indicates `DDL` statements */
    "db":"testdb",                    // Database name
    "table":"testtable",              // Table name
    "localip":"000.00.000.000",       // IP of the server where the instance is located
    "localport":0000,                 // Instance port
    "begintime":1511350073,           // Start time of the transaction to which the current event belongs
    "gtid":"0-2670193178-726233561",  // `GTID` of the transaction to which the current event belongs
    "event_index":"4",                // Number of the event in the transaction  
    "where":[                         // `where` field, which indicates the value of each field before the row is modified

    ],
    "field":[                         // `field` field, which indicates the value of each field after the row is modified
        "1",
        "'name1'"
    ]
}

The message format of a GTID event is as follows:

{                                    // A `GTID` event represents the start of a transaction
    "logtype":"mysqlbinlog",
    "eventtype":33,
    "eventtypestr":"gtid",
    "db":"sysdb",
    "table":"statustableforhb",
    "localip":"10.231.23.241",
    "localport":8810,
    "begintime":1511419963,
    "gtid":"35be190b-d019-11e7-ab7a-a0423f32c225:469",
    "event_index":"1"
}

The message format of an XID event is as follows:

{                                    // An `XID` event represents that a transaction has been committed
    "logtype":"mysqlbinlog",
    "eventtype":16,
    "eventtypestr":"xid",
    "db":"testsummer",
    "table":"test_table1",
    "localip":"10.231.23.241",
    "localport":8810,
    "begintime":1511419963,
    "gtid":"35be190b-d019-11e7-ab7a-a0423f32c225:469",
    "event_index":"5",
    "xid":"11866"
}

The message format of a QUERY event is as follows:

{
    "logtype":"mysqlbinlog",                          
    "eventtype":2,
    "eventtypestr":"query",         // `DDL` statement of a `QUERY` event
    "db":"testsummer",
    "table":"statustableforhb",
    "localip":"10.231.23.241",
    "localport":8810,
    "begintime":1511419941,
    "gtid":"35be190b-d019-11e7-ab7a-a0423f32c225:452",
    "event_index":"2",
    "sql":"create table test_table1 (id int primary key,name varchar(20))"
}

Subscription Method

You can use message events stored in a Kafka cluster to get the data in real time and process messages after getting them through the data subscription API provided by Tencent Cloud.