Upstream Database Configuration File of TiDB Data Migration

This document introduces the configuration file of the upstream database, including a configuration file template and the description of each configuration parameter in this file.

Configuration file template

The following is a configuration file template of the upstream database:

source-id: "mysql-replica-01"

# Whether to enable GTID.
enable-gtid: false

# Whether to enable relay log.
enable-relay: false
relay-binlog-name: ""     # The file name from which DM-worker starts to pull the binlog.
relay-binlog-gtid: ""     # The GTID from which DM-worker starts to pull the binlog.
# relay-dir: "relay-dir"  # The directory used to store relay log. The default value is "relay-dir". This configuration item is marked as deprecated since v6.1 and replaced by a parameter of the same name in the dm-worker configuration.


from:
  host: "127.0.0.1"
  port: 3306
  user: "root"
  password: "ZqMLjZ2j5khNelDEfDoUhkD5aV5fIJOe0fiog9w=" # The user password of the upstream database. It is recommended to use the password encrypted with dmctl.
  security:                       # The TLS configuration of the upstream database
    ssl-ca: "/path/to/ca.pem"
    ssl-cert: "/path/to/cert.pem"
    ssl-key: "/path/to/key.pem"

# purge:
#   interval: 3600
#   expires: 0
#   remain-space: 15

# checker:
#   check-enable: true
#   backoff-rollback: 5m0s
#   backoff-max: 5m0s       # The maximum value of backoff, should be larger than 1s

# Configure binlog event filters. New in DM v2.0.2
# case-sensitive: false
# filters:
# - schema-pattern: dmctl
#   table-pattern: t_1
#   events: []
#   sql-pattern:
#   - alter table .* add column `aaa` int
#   action: Ignore

Note

In DM v2.0.1, DO NOT set enable-gtid and enable-relay to true at the same time. Otherwise, it may cause loss of incremental data.

Configuration parameters

This section describes each configuration parameter in the configuration file.

Global configuration

Parameter	Description
`source-id`	Represents a MySQL instance ID.
`enable-gtid`	Determines whether to pull binlog from the upstream using GTID. The default value is `false`. In general, you do not need to configure `enable-gtid` manually. However, if GTID is enabled in the upstream database, and the primary/secondary switch is required, you need to set `enable-gtid` to `true`.
`enable-relay`	Determines whether to enable the relay log feature. The default value is `false`. This parameter takes effect from v5.4. Additionally, you can enable relay log dynamically using the `start-relay` command.
`relay-binlog-name`	Specifies the file name from which DM-worker starts to pull the binlog. For example, `"mysql-bin.000002"`. It only works when `enable_gtid` is `false`. If this parameter is not specified, DM-worker will start pulling from the earliest binlog file being replicated. Manual configuration is generally not required.
`relay-binlog-gtid`	Specifies the GTID from which DM-worker starts to pull the binlog. For example, `"e9a1fc22-ec08-11e9-b2ac-0242ac110003:1-7849"`. It only works when `enable_gtid` is `true`. If this parameter is not specified, DM-worker will start pulling from the latest GTID being replicated. Manual configuration is generally not required.
`relay-dir`	Specifies the relay log directory.
`host`	Specifies the host of the upstream database.
`port`	Specifies the port of the upstream database.
`user`	Specifies the username of the upstream database.
`password`	Specifies the user password of the upstream database. It is recommended to use the password encrypted with dmctl.
`security`	Specifies the TLS config of the upstream database. The configured file paths of the certificates must be accessible to all nodes. If the configured file paths are local paths, then all the nodes in the cluster need to store a copy of the certificates in the same path of each host.

Relay log cleanup strategy configuration (`purge`)

Generally, there is no need to manually configure these parameters unless there is a large amount of relay logs and disk capacity is insufficient.

Parameter	Description	Default value
`interval`	Sets the time interval at which relay logs are regularly checked for expiration, in seconds.	`3600`
`expires`	Sets the expiration time for relay logs, in hours. The relay log that is not written by the relay processing unit, or does not need to be read by the existing data migration task will be deleted by DM if it exceeds the expiration time. If this parameter is not specified, the automatic purge is not performed.	`0`
`remain-space`	Sets the minimum amount of free disk space, in gigabytes. When the available disk space is smaller than this value, DM-worker tries to delete relay logs.	`15`

Note

The automatic data purge strategy only takes effect when interval is not 0 and at least one of the two configuration items expires and remain-space is not 0.

Task status checker configuration (`checker`)

DM periodically checks the current task status and error message to determine if resuming the task will eliminate the error. If needed, DM automatically retries to resume the task. DM adjusts the checking interval using the exponential backoff strategy. Its behaviors can be adjusted by the following configuration.

Parameter	Description
`check-enable`	Whether to enable this feature.
`backoff-rollback`	If the current checking interval of backoff strategy is larger than this value and the task status is normal, DM will try to decrease the interval.
`backoff-max`	The maximum value of checking interval of backoff strategy, must be larger than 1 second.

Binlog event filter

Starting from DM v2.0.2, you can configure binlog event filters in the source configuration file.

Parameter	Description
`case-sensitive`	Determines whether the filtering rules are case-sensitive. The default value is `false`.
`filters`	Sets binlog event filtering rules. For details, see Binlog event filter parameter explanation.