Deploy TiDB on Alibaba Cloud Kubernetes

This document describes how to deploy a TiDB cluster on Alibaba Cloud Kubernetes with your laptop (Linux or macOS) for development or testing.

Prerequisites

• aliyun-cli >= 3.0.15 and configure aliyun-cli

  Note

  The access key must be granted permissions to control the corresponding resources.

• kubectl >= 1.12

• helm >= 2.11.0 and < 2.16.4

• jq >= 1.6

• terraform 0.12.*

You can use Cloud Shell of Alibaba Cloud to perform operations. All the tools have been pre-installed and configured in the Cloud Shell of Alibaba Cloud.

Required privileges

To deploy a TiDB cluster, make sure you have the following privileges:

• AliyunECSFullAccess
• AliyunESSFullAccess
• AliyunVPCFullAccess
• AliyunSLBFullAccess
• AliyunCSFullAccess
• AliyunEIPFullAccess
• AliyunECIFullAccess
• AliyunVPNGatewayFullAccess
• AliyunNATGatewayFullAccess

Overview of things to create

In the default configuration, you will create:

• A new VPC

• An ECS instance as the bastion machine

• A managed ACK (Alibaba Cloud Kubernetes) cluster with the following ECS instance worker nodes:

  • An auto-scaling group of 2 * instances (2 cores, 2 GB RAM) as ACK mandatory workers for the system service like CoreDNS
  • An auto-scaling group of 3 * ecs.g5.large instances for deploying the PD cluster
  • An auto-scaling group of 3 * ecs.i2.2xlarge instances for deploying the TiKV cluster
  • An auto-scaling group of 2 * ecs.c5.4xlarge instances for deploying the TiDB cluster
  • An auto-scaling group of 1 * ecs.c5.xlarge instance for deploying monitoring components
  • A 100 GB cloud disk used to store monitoring data

All the instances except ACK mandatory workers are deployed across availability zones (AZs) to provide cross-AZ high availability. The auto-scaling group ensures the desired number of healthy instances, so the cluster can auto-recover from node failure or even AZ failure.

Deploy

1. Configure the target region and Alibaba Cloud key (you can also set these variables in the terraform command prompt):

   export TF_VAR_ALICLOUD_REGION=<YOUR_REGION> && \
   export TF_VAR_ALICLOUD_ACCESS_KEY=<YOUR_ACCESS_KEY> && \
   export TF_VAR_ALICLOUD_SECRET_KEY=<YOUR_SECRET_KEY>
   

   The variables.tf file contains default settings of variables used for deploying the cluster. You can change it or use the -var option to override a specific variable to fit your need.

2. Use Terraform to set up the cluster.

   git clone --depth=1 https://github.com/pingcap/tidb-operator && \
   cd tidb-operator/deploy/aliyun
   

   Note that you must answer "yes" to terraform apply to continue:

   terraform init
   

   terraform apply
   

   If you get an error while running terraform apply, fix the error (for example, lack of permission) according to the error description and run terraform apply again.

   It takes 5 to 10 minutes to create the whole stack using terraform apply. Once installation is complete, the basic cluster information is printed:

   Apply complete! Resources: 3 added, 0 changed, 1 destroyed.
   
   Outputs:
   
   bastion_ip = 47.96.174.214
   cluster_id = c2d9b20854a194f158ef2bc8ea946f20e
   
   kubeconfig_file = /tidb-operator/deploy/aliyun/credentials/kubeconfig
   monitor_endpoint = 121.199.195.236:3000
   region = cn-hangzhou
   ssh_key_file = /tidb-operator/deploy/aliyun/credentials/my-cluster-keyZ.pem
   tidb_endpoint = 172.21.5.171:4000
   tidb_version = v3.0.0
   vpc_id = vpc-bp1v8i5rwsc7yh8dwyep5
   

   Note

   You can use the terraform output command to get the output again.

3. You can then interact with the ACK cluster using kubectl or helm

   export KUBECONFIG=$PWD/credentials/kubeconfig
   

   kubectl version
   

   helm ls
   

Access the database

You can connect the TiDB cluster via the bastion instance. All necessary information is in the output printed after installation is finished (replace the <> parts with values from the output):

ssh -i credentials/<cluster_name>-key.pem root@<bastion_ip>

mysql -h <tidb_slb_ip> -P 4000 -u root

Monitor

Visit <monitor_endpoint> to view the Grafana dashboards. You can find this information in the output of installation.

The initial login user account and password:

• User: admin
• Password: admin

Upgrade

To upgrade the TiDB cluster, set the tidb_version variable to a higher version in variables.tf and run terraform apply.

This may take a while to complete. You can watch the process using the following command:

kubectl get pods --namespace <tidb_cluster_name> -o wide --watch

Scale

To scale the TiDB cluster, modify tikv_count or tidb_count to your desired numbers, and then run terraform apply.

Configure

Configure TiDB Operator

You can adjust the variables.tf settings to configure TiDB Operator. Note that the operator_helm_values configuration item can provide a customized values.yaml configuration file for TiDB Operator. For example,

• Set operator_helm_values in terraform.tfvars:

  operator_helm_values = "./my-operator-values.yaml"
  

• Set operator_helm_values in main.tf:

  operator_helm_values = file("./my-operator-values.yaml")
  

In the default configuration, the Terraform script creates a new VPC. To use the existing VPC, set vpc_id in variable.tf. In this case, Kubernetes nodes are not deployed in AZs with vswitch not configured.

Configure the TiDB cluster

./my-cluster.yaml is the values.yaml configuration file in the TiDB cluster. You can configure the TiDB cluster by modifying this file. For supported configuration items, see Configure the TiDB cluster in Kubernetes.

Manage multiple TiDB clusters

To manage multiple TiDB clusters in a single Kubernetes cluster, you need to edit ./main.tf and add the tidb-cluster declaration based on your needs. For example:

module "tidb-cluster-dev" {
  source = "../modules/aliyun/tidb-cluster"
  providers = {
    helm = helm.default
  }

  cluster_name = "dev-cluster"
  ack          = module.tidb-operator

  pd_count                   = 1
  tikv_count                 = 1
  tidb_count                 = 1
  override_values            = file("dev-cluster.yaml")
}

module "tidb-cluster-staging" {
  source = "../modules/aliyun/tidb-cluster"
  providers = {
    helm = helm.default
  }

  cluster_name = "staging-cluster"
  ack          = module.tidb-operator

  pd_count                   = 3
  tikv_count                 = 3
  tidb_count                 = 2
  override_values            = file("staging-cluster.yaml")
}

All the configurable parameters in tidb-cluster are as follows:

Manage multiple Kubernetes clusters

It is recommended to use a separate Terraform module to manage a specific Kubernetes cluster. (A Terraform module is a directory that contains the .tf script.)

deploy/aliyun combines multiple reusable Terraform scripts in deploy/modules. To manage multiple clusters, perform the following operations in the root directory of the tidb-operator project:

1. Create a directory for each cluster. For example:

   mkdir -p deploy/aliyun-staging
   

2. Refer to main.tf in deploy/aliyun and write your own script. For example:

   provider "alicloud" {
       region     = <YOUR_REGION>
       access_key = <YOUR_ACCESS_KEY>
       secret_key = <YOUR_SECRET_KEY>
   }
   
   module "tidb-operator" {
       source     = "../modules/aliyun/tidb-operator"
   
       region          = <YOUR_REGION>
       access_key      = <YOUR_ACCESS_KEY>
       secret_key      = <YOUR_SECRET_KEY>
       cluster_name    = "example-cluster"
       key_file        = "ssh-key.pem"
       kubeconfig_file = "kubeconfig"
   }
   
   provider "helm" {
       alias    = "default"
       insecure = true
       install_tiller = false
       kubernetes {
           config_path = module.tidb-operator.kubeconfig_filename
       }
   }
   
   module "tidb-cluster" {
       source = "../modules/aliyun/tidb-cluster"
       providers = {
           helm = helm.default
       }
   
       cluster_name = "example-cluster"
       ack          = module.tidb-operator
   }
   
   module "bastion" {
       source = "../modules/aliyun/bastion"
   
       bastion_name             = "example-bastion"
       key_name                 = module.tidb-operator.key_name
       vpc_id                   = module.tidb-operator.vpc_id
       vswitch_id               = module.tidb-operator.vswitch_ids[0]
       enable_ssh_to_worker     = true
       worker_security_group_id = module.tidb-operator.security_group_id
   }
   

You can customize this script. For example, you can remove the module "bastion" declaration if you do not need the bastion machine.

Destroy

It may take a long time to finish destroying the cluster.

terraform destroy

If you fail to create a Kubernetes cluster, an error is reported and you cannot clean the cluster normally when you try to destroy the cluster. In this case, you need to manually remove the Kubernetes resources from the local state and proceed to destroy the rest resources:

terraform state list

terraform state rm module.ack.alicloud_cs_managed_kubernetes.k8s

Limitation

You cannot change pod cidr, service cidr and worker instance types once the cluster is created.