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Deploy Data Migration Using DM Binary

This document introduces how to quickly deploy the Data Migration (DM) cluster using DM binary.

Note

In the production environment, it is recommended to use TiUP to deploy a DM cluster.

Download DM binary

The DM binary is included in the TiDB Toolkit. To download the TiDB Toolkit, see Download TiDB Tools.

Sample scenario

Suppose that you deploy a DM cluster based on this sample scenario:

Two DM-worker nodes and three DM-master nodes are deployed on five servers.

Here is the address of each node:

Instance	Server address	Port
DM-master1	192.168.0.4	8261
DM-master2	192.168.0.5	8261
DM-master3	192.168.0.6	8261
DM-worker1	192.168.0.7	8262
DM-worker2	192.168.0.8	8262

Based on this scenario, the following sections describe how to deploy the DM cluster.

Note

If you deploy multiple DM-master or DM-worker instances in a single server, the port and working directory of each instance must be unique.
If you do not need to ensure high availability of the DM cluster, deploy only one DM-master node, and the number of deployed DM-worker nodes must be no less than the number of upstream MySQL/MariaDB instances to be migrated.
To ensure high availability of the DM cluster, it is recommended to deploy three DM-master nodes, and the number of deployed DM-worker nodes must be greater than the number of upstream MySQL/MariaDB instances to be migrated (for example, the number of DM-worker nodes is two more than the number of upstream instances).
Make sure that the ports among the following components are interconnected:
- The 8291 ports among the DM-master nodes are interconnected.
- Each DM-master node can connect to the 8262 ports of all DM-worker nodes.
- Each DM-worker node can connect to the 8261 port of all DM-master nodes.

Deploy DM-master

You can configure DM-master by using command-line parameters or the configuration file.

DM-master command-line parameters

The following is the description of DM-master command-line parameters:

./dm-master --help

Usage of dm-master:
  -L string
        log level: debug, info, warn, error, fatal (default "info")
  -V    prints version and exit
  -advertise-addr string
        advertise address for client traffic (default "${master-addr}")
  -advertise-peer-urls string
        advertise URLs for peer traffic (default "${peer-urls}")
  -config string
        path to config file
  -data-dir string
        path to the data directory (default "default.${name}")
  -initial-cluster string
        initial cluster configuration for bootstrapping, e.g. dm-master=http://127.0.0.1:8291
  -join string
        join to an existing cluster (usage: cluster's "${master-addr}" list, e.g. "127.0.0.1:8261,127.0.0.1:18261"
  -log-file string
        log file path
  -master-addr string
        master API server and status addr
  -name string
        human-readable name for this DM-master member
  -peer-urls string
        URLs for peer traffic (default "http://127.0.0.1:8291")
  -print-sample-config
        print sample config file of dm-worker

Note

In some situations, you cannot use the above method to configure DM-master because some configurations are not exposed to the command line. In such cases, use the configuration file instead.

DM-master configuration file

The following is the configuration file of DM-master. It is recommended that you configure DM-master by using this method.

Write the following configuration to conf/dm-master1.toml:

# Master Configuration.
name = "master1"

# Log configurations.
log-level = "info"
log-file = "dm-master.log"

# The listening address of DM-master.
master-addr = "192.168.0.4:8261"

# The peer URLs of DM-master.
peer-urls = "192.168.0.4:8291"

# The value of `initial-cluster` is the combination of the `advertise-peer-urls` value of all DM-master nodes in the initial cluster.
initial-cluster = "master1=http://192.168.0.4:8291,master2=http://192.168.0.5:8291,master3=http://192.168.0.6:8291"

Execute the following command in the terminal to run DM-master:
```
./dm-master -config conf/dm-master1.toml
```
Note
The console does not output logs after this command is executed. If you want to view the runtime log, you can execute tail -f dm-master.log.
For DM-master2 and DM-master3, change name in the configuration file to master2 and master3 respectively, and change peer-urls to 192.168.0.5:8291 and 192.168.0.6:8291 respectively. Then repeat Step 2.

Deploy DM-worker

You can configure DM-worker by using command-line parameters or the configuration file.

DM-worker command-line parameters

The following is the description of the DM-worker command-line parameters:

./dm-worker --help

Usage of worker:
  -L string
        log level: debug, info, warn, error, fatal (default "info")
  -V    prints version and exit
  -advertise-addr string
        advertise address for client traffic (default "${worker-addr}")
  -config string
        path to config file
  -join string
        join to an existing cluster (usage: dm-master cluster's "${master-addr}")
  -keepalive-ttl int
        dm-worker's TTL for keepalive with etcd (in seconds) (default 10)
  -log-file string
        log file path
  -name string
        human-readable name for DM-worker member
  -print-sample-config
        print sample config file of dm-worker
  -worker-addr string
        listen address for client traffic

Note

In some situations, you cannot use the above method to configure DM-worker because some configurations are not exposed to the command line. In such cases, use the configuration file instead.

DM-worker configuration file

The following is the DM-worker configuration file. It is recommended that you configure DM-worker by using this method.

Write the following configuration to conf/dm-worker1.toml:

# Worker Configuration.
name = "worker1"

# Log configuration.
log-level = "info"
log-file = "dm-worker.log"

# DM-worker address.
worker-addr = ":8262"

# The master-addr configuration of the DM-master nodes in the cluster.
join = "192.168.0.4:8261,192.168.0.5:8261,192.168.0.6:8261"

Execute the following command in the terminal to run DM-worker:
```
./dm-worker -config conf/dm-worker1.toml
```
For DM-worker2, change name in the configuration file to worker2. Then repeat Step 2.

Now, a DM cluster is successfully deployed.