DM also implements an advanced task configuration file which provides greater flexibility and more control over DM.
For the feature and configuration of each configuration item, see Data replication features.
For description of important concepts including
source-id and the DM-worker ID, see Important concepts.
The following is a task configuration file template which allows you to perform basic data replication tasks.
--- # ----------- Global configuration ----------- ## ********** Basic configuration ************ ```yaml name: test # The name of the task. Should be globally unique. task-mode: all # The task mode. Can be set to `full`/`incremental`/`all`. target-database: # Configuration of the downstream database instance. host: "127.0.0.1" port: 4000 user: "root" password: "" # The dmctl encryption is needed when the password is not empty. ## ******** Feature configuration set ********** # The filter rule set of the black white list of the matched table of the upstream database instance. black-white-list: bw-rule-1: # The name of the black and white lists filtering rule of the table matching the upstream database instance. do-dbs: ["all_mode"] # white list of upstream tables needs to be replicated. # ----------- Instance configuration ----------- mysql-instances: # The ID of the upstream instance or replication group. It can be configured by referring to the `source-id` in the `dm-master.toml` file. - source-id: "mysql-replica-01" black-white-list: "bw-rule-1" mydumper-thread: 4 # The number of threads that Mydumper uses for dumping data. loader-thread: 16 # The number of threads that Loader uses for loading data. syncer-thread: 16 # The number of threads that Syncer uses for replicating incremental data. - source-id: "mysql-replica-02" black-white-list: "bw-rule-1" mydumper-thread: 4 loader-thread: 16 syncer-thread: 16
Refer to the comments in the template to see more details. Specific instruction about
task-mode are as follows:
fullonly makes a full backup of the upstream database and then imports the full data to the downstream database.
incremental: Only replicates the incremental data of the upstream database to the downstream database using the binlog. You can set the
metaconfiguration item of the instance configuration to specify the starting position of incremental replication.
incremental. Makes a full backup of the upstream database, imports the full data to the downstream database, and then uses the binlog to make an incremental replication to the downstream database starting from the exported position during the full backup process (binlog position).
For basic applications, you only need to modify the black and white lists filtering rule. Refer to the comments about
black-white-list in the template or Black & white table lists to see more details.
This part defines the subtask of data replication. DM supports replicating data from one or multiple MySQL instances to the same instance.
For more details, refer to the comments about
mysql-instances in the template.
In some cases, you might need to update the task configuration. For example, if you set
all when resetting the data replication task, you need to set
false after the task is reset. This can prevent the task from being replicated the next time the task is started.
It is recommended to update the modified configuration to the DM cluster by executing the
start-task commands, since the DM cluster persists the task configuration. If the task configuration file is modified directly, without restarting the task, the configuration changes does not take effect. In this case, the DM cluster still reads the previous task configuration when the DM cluster is restarted.
To illustrate how to modify the task configuration, the following is an example of modifying
Modify the task configuration file and set
Stop the task by executing the
Start the task by executing the