Maxwell

Maxwell reads and converts MySQL binlogs into the JavaScript Object Notation (JSON) format. It is used to capture all data change events in a database. This topic describes how to use Maxwell to export data of a MySQL-compatible tenant of OceanBase Cloud in the JSON format.

Prerequisites

Before you use Maxwell, make sure that the following conditions are met:

• You have activated the Binlog service for OceanBase Cloud in the MySQL compatible mode. For more information, see Procedure.
• You have installed Java 1.8 or later.
• You have downloaded Maxwell. For more information, see the description of Maxwell at GitHub.

Procedure

1. Activate the Binlog service in OceanBase Cloud. In the left-side navigation pane of the OceanBase Cloud console, choose Instances > Tenant Management and activate the Binlog service. For more information, see Activate the Binlog service.

2. Configure Maxwell. Edit the config.properties file in the working directory of Maxwell. If this file does not exist, copy config.properties.example, rename it into config.properties, and edit the file.

   user=maxwell
   password=yourpassword
   host=IP address of the server of the source MySQL-compatible tenant of OceanBase Cloud
   producer=stdout
   

   stdout indicates the standard output mode. With this configuration, Maxwell directly exports data to the console. To enable Maxwell to export data to other targets such as Kafka, change the value of producer and related configurations.

3. Start Maxwell.

   Run the following command to start Maxwell:

   bin/maxwell --config config.properties
   

4. View data changes Change data in OceanBase Cloud, for example, insert, update, or delete data. Then, observe the JSON data exported by Maxwell. Set the output mode of Maxwell to stdout in the command in Step 3. The possible return results are as follows:

    {
    "database": "mydb",
    "table": "mytable",
    "type": "insert",
    "ts": 1589372847,
    "xid": 12345678,
    "commit": true,
    "data": {
        "id": 1,
        "column1": "value1",
        "column2": "value2"
    }
    }
   

   The return results show that data was inserted into the mydb.mytable table.

In the following example, the latin1 character set is deleted from the CREATE TABLE statement of Maxwell.

CREATE TABLE IF NOT EXISTS `databases` (
  id        bigint auto_increment NOT NULL primary key,
  schema_id bigint,
  name      varchar(255) charset 'utf8',
  charset   varchar(255),
  index (schema_id)
);

This example describes how to operate a single metadata table. You need to perform the same operations on other metadata tables.