Tools on Kubernetes
Operations on TiDB on Kubernetes require some open source tools. In the meantime, there are some special requirements for operations using TiDB tools in the Kubernetes environment. This documents introduces in details the related operation tools for TiDB on Kubernetes.
Use PD Control on Kubernetes
PD Control is the command-line tool for PD (Placement Driver). To use PD Control to operate on TiDB clusters on Kubernetes, firstly you need to establish the connection from local to the PD service using kubectl port-forward
:
kubectl port-forward -n ${namespace} svc/${cluster_name}-pd 2379:2379 &>/tmp/portforward-pd.log &
After the above command is executed, you can access the PD service via 127.0.0.1:2379
, and then use the default parameters of pd-ctl
to operate. For example:
pd-ctl -d config show
Assume that your local port 2379
has been occupied and you want to switch to another port:
kubectl port-forward -n ${namespace} svc/${cluster_name}-pd ${local_port}:2379 &>/tmp/portforward-pd.log &
Then you need to explicitly assign a PD port for pd-ctl
:
pd-ctl -u 127.0.0.1:${local_port} -d config show
Use TiKV Control on Kubernetes
TiKV Control is the command-line tool for TiKV. When using TiKV Control for TiDB clusters on Kubernetes, be aware that each operation mode involves different steps, as described below:
Remote Mode: In this mode,
tikv-ctl
accesses the TiKV service or the PD service through network. Firstly you need to establish the connection from local to the PD service and the target TiKV node usingkubectl port-forward
:kubectl port-forward -n ${namespace} svc/${cluster_name}-pd 2379:2379 &>/tmp/portforward-pd.log &kubectl port-forward -n ${namespace} ${pod_name} 20160:20160 &>/tmp/portforward-tikv.log &After the connection is established, you can access the PD service and the TiKV node via the corresponding port in local:
tikv-ctl --host 127.0.0.1:20160 ${subcommands}tikv-ctl --pd 127.0.0.1:2379 compact-clusterLocal Mode:In this mode,
tikv-ctl
accesses data files of TiKV, and the running TiKV instances must be stopped. To operate in the local mode, first you need to enter the Debug Mode to turn off automatic re-starting for the TiKV instance, stop the TiKV process, and enter the target TiKV Pod and usetikv-ctl
to perform the operation. The steps are as follows:Enter the debug mode:
kubectl annotate pod ${pod_name} -n ${namespace} runmode=debugStop the TiKV process:
kubectl exec ${pod_name} -n ${namespace} -c tikv -- kill -s TERM 1Wait for the TiKV container to restart, and enter the container:
kubectl exec -it ${pod_name} -n ${namespace} -- shStart using
tikv-ctl
in local mode. The default db path in the TiKV container is/var/lib/tikv/db
:./tikv-ctl --data-dir /var/lib/tikv size -r 2
Use TiDB Control on Kubernetes
TiDB Control is the command-line tool for TiDB. To use TiDB Control on Kubernetes, you need to access the TiDB node and the PD service from local. It is suggested you turn on the connection from local to the TiDB node and the PD service using kubectl port-forward
:
kubectl port-forward -n ${namespace} svc/${cluster_name}-pd 2379:2379 &>/tmp/portforward-pd.log &
kubectl port-forward -n ${namespace} ${pod_name} 10080:10080 &>/tmp/portforward-tidb.log &
Then you can use the tidb-ctl
:
tidb-ctl schema in mysql
Use Helm
Helm is a package management tool for Kubernetes. The installation steps are as follows:
Install the Helm client
Refer to Helm official documentation to install the Helm client.
If the server does not have access to the Internet, you need to download Helm on a machine with Internet access, and then copy it to the server. Here is an example of installing the Helm client 3.4.1
:
wget https://get.helm.sh/helm-v3.4.1-linux-amd64.tar.gz
tar zxvf helm-v3.4.1-linux-amd64.tar.gz
After decompression, you can see the following files:
linux-amd64/
linux-amd64/README.md
linux-amd64/helm
linux-amd64/LICENSE
Copy the linux-amd64/helm
file to the server and place it under the /usr/local/bin/
directory.
Then execute helm version
. If the command outputs normally, the Helm installation is successful:
helm version
version.BuildInfo{Version:"v3.4.1", GitCommit:"c4e74854886b2efe3321e185578e6db9be0a6e29", GitTreeState:"clean", GoVersion:"go1.14.11"}
Configure the Helm repo
Kubernetes applications are packed as charts in Helm. PingCAP provides the following Helm charts for TiDB on Kubernetes:
tidb-operator
: used to deploy TiDB Operator;tidb-cluster
: used to deploy TiDB clusters;tidb-backup
: used to back up or restore TiDB clusters;tidb-lightning
: used to import data into a TiDB cluster;tidb-drainer
: used to deploy TiDB Drainer;
These charts are hosted in the Helm chart repository https://charts.pingcap.org/
maintained by PingCAP. You can add this repository to your local server or computer using the following command:
helm repo add pingcap https://charts.pingcap.org/
Then you can search the chart provided by PingCAP using the following command:
helm search repo pingcap
NAME CHART VERSION APP VERSION DESCRIPTION
pingcap/tidb-backup v1.5.4 A Helm chart for TiDB Backup or Restore
pingcap/tidb-cluster v1.5.4 A Helm chart for TiDB Cluster
pingcap/tidb-drainer v1.5.4 A Helm chart for TiDB Binlog drainer.
pingcap/tidb-lightning v1.5.4 A Helm chart for TiDB Lightning
pingcap/tidb-operator v1.5.4 v1.5.4 tidb-operator Helm chart for Kubernetes
When a new version of chart has been released, you can use helm repo update
to update the repository cached locally:
helm repo update
Helm common operations
Common Helm operations include helm install
, helm upgrade
, and helm uninstall
. Helm chart usually contains many configurable parameters which could be tedious to configure manually. For convenience, it is recommended that you configure using a YAML file. Based on the conventions in the Helm community, the YAML file used for Helm configuration is named values.yaml
in this document.
Before performing the deploy, upgrade and deploy, you can view the deployed applications via helm ls
:
helm ls
When performing a deployment or upgrade, you must specify the chart name (chart-name
) and the name for the deployed application (release-name
). You can also specify one or multiple values.yaml
files to configure charts. In addition, you can use chart-version
to specify the chart version (by default the latest GA is used). The steps in command line are as follows:
Install:
helm install ${release_name} ${chart_name} --namespace=${namespace} --version=${chart_version} -f ${values_file}Upgrade (the upgrade can be either modifying the
chart-version
to upgrade to the latest chart version, or editing thevalues.yaml
file to update the configuration):helm upgrade ${release_name} ${chart_name} --version=${chart_version} -f ${values_file}Delete:
To delete the application deployed by Helm, run the following command:
helm uninstall ${release_name} -n ${namespace}
For more information on Helm, refer to Helm Documentation.
Use Helm chart offline
If the server has no Internet access, you cannot configure the Helm repo to install the TiDB Operator component and other applications. At this time, you need to download the chart file needed for cluster installation on a machine with Internet access, and then copy it to the server.
Use the following command to download the chart file required for cluster installation:
wget http://charts.pingcap.org/tidb-operator-v1.5.4.tgz
wget http://charts.pingcap.org/tidb-drainer-v1.5.4.tgz
wget http://charts.pingcap.org/tidb-lightning-v1.5.4.tgz
Copy these chart files to the server and decompress them. You can use these charts to install the corresponding components by running the helm install
command. Take tidb-operator
as an example:
tar zxvf tidb-operator.v1.5.4.tgz
helm install ${release_name} ./tidb-operator --namespace=${namespace}
Use Terraform
Terraform is a Infrastructure as Code management tool. It enables users to define their own infrastructure in a manifestation style, based on which execution plans are generated to create or schedule real world compute resources. TiDB on Kubernetes use Terraform to create and manage TiDB clusters on public clouds.
Follow the steps in Terraform Documentation to install Terraform.