MySQL Database-level Sync
Overview
Database-level Sync is implemented via the native FROM MYSQL (...) TO DATABASE (...) DDL, using a database as the sync unit with a Doris database as the target container. You can sync one, several, or all tables via include_tables; on first sync Doris automatically creates downstream primary-key tables and keeps primary keys consistent with the upstream. Suitable for mirror replication scenarios where downstream schema should track upstream automatically and no SQL processing is needed.
By integrating Flink CDC, Doris reads change logs from MySQL and continuously writes full + incremental data of a group of tables into Doris via Stream Load. If you need column mapping, filtering, or data transformation during sync, see MySQL Table-level Sync.
Notes:
- Currently only at-least-once semantics are guaranteed.
- Only primary key tables are supported for synchronization.
- LOAD privilege is required. If the downstream table does not exist, CREATE privilege is also required.
- During automatic table creation, if the target table already exists, it will be skipped, and users can customize tables according to different scenarios.
Quick Start
Creating an Import Job
Use CREATE STREAMING JOB to create a continuous import job:
CREATE JOB multi_table_sync
ON STREAMING
FROM MYSQL (
"jdbc_url" = "jdbc:mysql://127.0.0.1:3306",
"driver_url" = "mysql-connector-java-8.0.25.jar",
"driver_class" = "com.mysql.cj.jdbc.Driver",
"user" = "root",
"password" = "123456",
"database" = "test",
"include_tables" = "user_info,order_info",
"offset" = "initial"
)
TO DATABASE target_test_db (
"table.create.properties.replication_num" = "1" -- Set to 1 for single BE deployment
)
Check Import Status
select * from jobs("type"="insert") where ExecuteType = "STREAMING"
Id: 1765332859199
Name: mysql_db_sync
Definer: root
ExecuteType: STREAMING
RecurringStrategy: \N
Status: RUNNING
ExecuteSql: FROM MYSQL('include_tables'='user_info','database'='test','driver_class'='com.mysql.cj.jdbc.Driver','driver_url'='mysql-connector-java-8.0.25.jar','offset'='initial','jdbc_url'='jdbc:mysql://127.0.0.1:3306','user'='root' ) TO DATABASE target_test_db ('table.create.properties.replication_num'='1')
CreateTime: 2025-12-10 10:19:35
SucceedTaskCount: 1
FailedTaskCount: 0
CanceledTaskCount: 0
Comment:
Properties: \N
CurrentOffset: {"ts_sec":"1765284495","file":"binlog.000002","pos":"9350","kind":"SPECIFIC","splitId":"binlog-split","row":"1","event":"2","server_id":"1"}
EndOffset: \N
LoadStatistic: {"scannedRows":24,"loadBytes":1146,"fileNumber":0,"fileSize":0}
ErrorMsg: \N
Modify Import Job
ALTER JOB <job_name>
FROM MYSQL (
"user" = "root",
"password" = "123456"
)
TO DATABASE target_test_db
For more common operations (pause, resume, delete, check Task, etc.), see Continuous Load Overview.
Source Parameters
| Parameter | Default | Description |
|---|---|---|
| jdbc_url | - | MySQL JDBC connection string |
| driver_url | - | JDBC driver jar path. Supports file name, local absolute path, and HTTP URL. See JDBC Catalog Overview for details. |
| driver_class | - | JDBC driver class name |
| user | - | Database username |
| password | - | Database password |
| database | - | Database name |
| include_tables | - | Tables to synchronize, comma separated. If not specified, all tables will be synchronized by default. |
| offset | initial | initial: full + incremental sync, latest: incremental only |
| snapshot_split_size | 8096 | Split size (in rows). During full sync, the table is divided into multiple splits |
| snapshot_parallelism | 1 | Parallelism during full sync phase, i.e., max splits per task |
Reference
Import Command
Syntax for creating a database-level sync job:
CREATE JOB <job_name>
ON STREAMING
[job_properties]
[ COMMENT <comment> ]
FROM MYSQL (
[source_properties]
)
TO DATABASE <target_db> (
[target_properties]
)
| Module | Description |
|---|---|
| job_name | Job name |
| job_properties | General import parameters |
| comment | Job comment |
| source_properties | MySQL source parameters |
| target_properties | Doris target DB parameters |
Doris Target DB Parameters
| Parameter | Default | Description |
|---|---|---|
| table.create.properties.* | - | Table properties when creating, e.g. replication_num |
| load.strict_mode | - | Whether to enable strict mode. Disabled by default. |
| load.max_filter_ratio | - | The maximum allowed filtering ratio within a sampling window. Must be between 0 and 1 (inclusive). The default value is 0, indicating zero tolerance. The sampling window equals max_interval * 10. If, within this window, the ratio of erroneous rows to total rows exceeds max_filter_ratio, the scheduled job will be paused and requires manual intervention to address data quality issues. |