Deploy a DM Cluster Offline Using TiUP (Experimental)

Warning

Using TiUP to deploy a DM cluster offline is still an experimental feature. It is NOT recommended to use this feature in production.

This document describes how to deploy a DM cluster offline using TiUP.

Step 1: Prepare the TiUP offline component package

Install the TiUP package manager online.
1. Install the TiUP tool:
```
curl --proto '=https' --tlsv1.2 -sSf https://tiup-mirrors.pingcap.com/install.sh | sh
```
2. Redeclare the global environment variables:
```
source .bash_profile
```
3. Confirm whether TiUP is installed:
```
which tiup
```

Pull the mirror using TiUP

Pull the needed components on a machine that has access to the Internet:

export version=v2.0.3  # You can modify it to the needed version.
tiup mirror clone tidb-dm-${version}-linux-amd64 --os=linux --arch=amd64 \
    --dm-master=${version} --dm-worker=${version} --dmctl=${version} \
    --alertmanager=v0.17.0 --grafana=v4.0.3 --prometheus=v4.0.3 \
    --tiup=v$(tiup --version|grep 'tiup'|awk -F ' ' '{print $1}') --dm=v$(tiup --version|grep 'tiup'|awk -F ' ' '{print $1}')

The command above creates a directory named tidb-dm-${version}-linux-amd64 in the current directory, which contains the component package managed by TiUP.

Pack the component package by using the tar command and send the package to the control machine in the isolated environment:
```
tar czvf tidb-dm-${version}-linux-amd64.tar.gz tidb-dm-${version}-linux-amd64
```
tidb-dm-${version}-linux-amd64.tar.gz is an independent offline environment package.

Step 2: Deploy the offline TiUP component

After sending the package to the control machine of the target cluster, install the TiUP component by running the following command:

export version=v2.0.3 # You can modify it to the needed version.
tar xzvf tidb-dm-${version}-linux-amd64.tar.gz
sh tidb-dm-${version}-linux-amd64/local_install.sh
source /home/tidb/.bash_profile

The local_install.sh script automatically executes the tiup mirror set tidb-dm-${version}-linux-amd64 command to set the current mirror address to tidb-dm-${version}-linux-amd64.

To switch the mirror to another directory, manually execute the tiup mirror set <mirror-dir> command. If you want to switch back to the official mirror, execute tiup mirror set https://tiup-mirrors.pingcap.com.

Step 3: Edit the initialization configuration file

You need to edit the cluster initialization configuration file according to different cluster topologies.

For the full configuration template, refer to the TiUP configuration parameter template. Create a configuration file topology.yaml. In other combined scenarios, edit the configuration file as needed according to the templates.

The configuration of deploying three DM-masters, three DM-workers, and one monitoring component instance is as follows:

---
global:
  user: "tidb"
  ssh_port: 22
  deploy_dir: "/home/tidb/dm/deploy"
  data_dir: "/home/tidb/dm/data"
  # arch: "amd64"

master_servers:
  - host: 172.19.0.101
  - host: 172.19.0.102
  - host: 172.19.0.103

worker_servers:
  - host: 172.19.0.101
  - host: 172.19.0.102
  - host: 172.19.0.103

monitoring_servers:
  - host: 172.19.0.101

grafana_servers:
  - host: 172.19.0.101

alertmanager_servers:
  - host: 172.19.0.101

Note

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).
For parameters that should be globally effective, configure these parameters of corresponding components in the server_configs section of the configuration file.
For parameters that should be effective on a specific node, configure these parameters in config of this node.
Use . to indicate the subcategory of the configuration, such as log.slow-threshold. For more formats, see TiUP configuration template.
For more parameter description, see master config.toml.example and worker config.toml.example.
Make sure that the ports among the following components are interconnected:
- The peer_port (8291 by default) among the DM-master nodes are interconnected.
- Each DM-master node can connect to the port of all DM-worker nodes (8262 by default).
- Each DM-worker node can connect to the port of all DM-master nodes (8261 by default).
- The TiUP nodes can connect to the port of all DM-master nodes (8261 by default).
- The TiUP nodes can connect to the port of all DM-worker nodes (8262 by default).

Step 4: Execute the deployment command

Note

You can use secret keys or interactive passwords for security authentication when you deploy DM using TiUP:

If you use secret keys, you can specify the path of the keys through -i or --identity_file;
If you use passwords, add the -p flag to enter the password interaction window;
If password-free login to the target machine has been configured, no authentication is required.

tiup dm deploy dm-test ${version} ./topology.yaml --user root [-p] [-i /home/root/.ssh/gcp_rsa]

In the above command:

The name of the deployed DM cluster is dm-test.
The version of the DM cluster is ${version}. You can view the latest versions supported by TiUP by running tiup list dm-master.
The initialization configuration file is topology.yaml.
--user root: Log in to the target machine through the root key to complete the cluster deployment, or you can use other users with ssh and sudo privileges to complete the deployment.
[-i] and [-p]: optional. If you have configured login to the target machine without password, these parameters are not required. If not, choose one of the two parameters. [-i] is the private key of the root user (or other users specified by --user) that has access to the target machine. [-p] is used to input the user password interactively.
TiUP DM uses the embedded SSH client. If you want to use the SSH client native to the control machine system, edit the configuration according to using the system's native SSH client to connect to the cluster.

At the end of the output log, you will see Deployed cluster `dm-test` successfully. This indicates that the deployment is successful.

Step 5: Check the clusters managed by TiUP

tiup dm list

TiUP supports managing multiple DM clusters. The command above outputs information of all the clusters currently managed by TiUP, including the name, deployment user, version, and secret key information:

Name  User  Version  Path                                  PrivateKey
----  ----  -------  ----                                  ----------
dm-test  tidb  v2.0.3  /root/.tiup/storage/dm/clusters/dm-test  /root/.tiup/storage/dm/clusters/dm-test/ssh/id_rsa

Step 6: Check the status of the deployed DM cluster

To check the status of the dm-test cluster, execute the following command:

tiup dm display dm-test

Expected output includes the instance ID, role, host, listening port, and status (because the cluster is not started yet, so the status is Down/inactive), and directory information of the dm-test cluster.

Step 7: Start the cluster

tiup dm start dm-test

If the output log includes Started cluster `dm-test` successfully, the start is successful.

Step 8: Verify the running status of the cluster

Check the DM cluster status using TiUP:

tiup dm display dm-test

If the Status is Up in the output, the cluster status is normal.