PolarDB for MySQL to Kafka

BladePipe supports data replication from PolarDB for MySQL to Kafka. View supported migration, sync, verification, and connector capabilities.

Target DataSource：

Kafka

Connection

Basic Functions

Function	Description
Full Data Migration	Migrate data by sequentially scanning data in tables and writing it in batches to the message-oriented middleware.
Incremental Data Sync	Sync of common DML like INSERT, UPDATE, DELETE is supported.
Subscription Modification	Add, delete, or modify the subscribed tables with support for historical data migration. For more information, see Modify Subscription.
Position Resetting	Reset positions by file position or timestamp. Allow re-consumption of incremental data logs in a past period or since a specific Binlog file and position.
Metadata Retrieval	Retrieve the target metadata with filtering conditions or target primary keys set from the source table.

Advanced Functions

Function	Description
Message Format	The following message formats are supported. See Message Format. CloudCanal format AlibabaCanal format
Topic Mapping Rules	By default, Topic is formed by connecting source instance id, database, and table with . in between (e.g., pc-vgpq6q097174t6t.dingtax.app_key). Also, it supports the mapping rules, namely, keeping the name the same as that in Source, converting the text to lowercase, converting the text to uppercase.
Table-level Topic	Create Topics corresponding to the tables in the Source, and the table partitions can be obtained automatically.
DDL Dedicated Topic	Allow specifying a Topic for DDL. If not specified, DDL time is placed in partition 0 of the Topic created from the corresponding table.
Online DDL Compatibility	Support GH-OST, PT-OSC, Aliyun DMS Online DDL. After changes, synchronize messages with the latest schema (e.g., newly added or modified columns, removed columns).
Scheduled Full Data Migration	For more information, see Create Scheduled Full Data DataJob.
Custom Code	For more information, see Custom Code Processing, Debug Custom Code and Logging in Custom Code.
Data Filtering Conditions	Support data filtering using WHERE conditions, with SQL-92 as the SQL language. For more information, see Data Filtering.
Setting Target Primary Key	Change the primary key to another field to facilitate data aggregation and other operations.

FAQ

• How to handle MySQL DataJob latency?

• What to do when binary Log cannot be found in MySQL Source?

• What to do when access to schema in MySQL Source is denied?

• Tips: MySQL source-related FAQs are also applicable to MySQL-compatible data sources.

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Source

Prerequisites

Prerequisite	Description
Permissions for Account	A privileged account or a normal account with read and write permissions of PolarDbMySQL.
Enable Binlog	In the PolarDbMySQL instance, click Details > Configuration and Management > Parameter Configuration > Set the value of loose_polar_log_bin to true.
Character Set	Support utf8, utf8mb4, latin1. Other encodings have not been tested.

Parameters

Parameter	Description
parseBinlogParallel	Number of threads for parallel parsing of Binlog in Incremental DataJobs.
parseBinlogBufferSize	Size of the circular buffer for parsing Binlog in Incremental DataJobs.
maxTransactionSize	Maximum number of data rows per transaction. If exceeded, the transaction will be split and flushed in parts.
limitThroughputMb	Limit the throughput of incremental Binlogs.
extraDDL	Support synchronization of additional DDL, including PT, GHOST, ALI_DMS, and PT_GHOST.
needJsonEscape	Escape special characters in JSON to be written to the target database.

Tips: To modify the general parameters, see General Parameters and Functions.

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Target

Prerequisites

Prerequisite	Description
Port Preparation	Allow the migration and sync node (Worker) to connect to the Kafka ports.

Parameters

Parameter	Description
schemaFormat	Message format. For more information, see Message Format.
batchWriteSize	The maximum data size of a single message. If the size exceeds the limit, the message will be split.
defaultTopic	Messages that cannot find a corresponding topic are sent to this topic (such as adding a new table)
ddlTopic	A topic specifically used to receive DDL events. If it is empty, the DDL events will be sent to the 0th partition of the corresponding topic.
compressionType	Kafka compression.type parameter to set compression algorithm. Support GZIP, SNAPPY, LZ4, ZSTD.
batchSize	Kafka batch.size parameter.
acks	Kafka acks parameter. By default, it is all.
maxRequestBytes	Kafka max.request.size parameter.
lingerMs	Kafka linger.ms parameter. By default, it is 1.
envelopSchemaInclude	When schemaFormat is set to DEBEZIUM_ENVELOP_JSON_FOR_MQ, it means whether the message body contains schema information.
customClientProps	Custom properties passed to the Kafka client in JSON format. The key is the parameter name and the value is the parameter value. This setting takes the highest priority. For example: AWS IAM Access Control

Tips: To modify the general parameters, see General Parameters and Functions.