ApeCloud MySQL Proxy

Before you start

1. Install kbcli.

2. Install Helm.

3. Install KubeBlocks.

   You can run kbcli playground init to install a k3d cluster and KubeBlocks. For details, refer to Try KubeBlocks on your laptop or Try KubeBlocks on cloud.

   kbcli playground init
   
   # Use --version to specify a version
   kbcli playground init --version='x.y.z'

   Or if you already have a Kubernetes cluster, you can install KubeBlocks by kbcli or by Helm directly.

4. Prepare an ApeCloud MySQL RaftGroup named mycluster for demonstrating how to enable the proxy function for an existing cluster. Refer to Create a MySQL cluster for details.

Create a Proxy Cluster

It is recommended to use kbcli to create an ApeCloud MySQL Proxy Cluster.

kbcli

1. Enable the etcd Addon and create an etcd cluster.

   1. Install and enable the etcd Addon. You need to install the etcd Addon first since the etcd Addon is not installed by default. Refer to Addons installation tutorial for details.

      # 1. Check whether the KubeBlocks Addon index is added
      kbcli addon index list
      
      # If the list is empty, add the index
      kbcli addon index add kubeblocks https://github.com/apecloud/block-index.git
      
      # 2. Search the etcd Addon
      kbcli addon search etcd
      
      # 3. Install the etcd Addon
      kbcli addon install etcd --index kubeblocks --version 0.9.0
      
      # 4. Enable the etcd Addon
      kbcli addon enable etcd
      
      # 5. Check whether the etcd Addon is enabled.
      kbcli addon list

   2. Create an etcd cluster.

      kbcli cluster create myetcd --cluster-definition etcd

   3. Check the status of the etcd service

      kbcli cluster list myetcd

2. View the etcd service address or the etcd pod address.

   kubectl get service
   >
   NAME                             TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                                                  AGE
   kubernetes                       ClusterIP   10.96.0.1        <none>        443/TCP                                                  85d
   myetcd-etcd                      ClusterIP   10.101.227.143   <none>        2379/TCP                                                 111s
   myetcd-etcd-headless             ClusterIP   None             <none>        2379/TCP,2380/TCP,3501/TCP,50001/TCP                     111s

3. Create an ApeCloud MySQL Proxy cluster.

   helm repo add kubeblocks https://apecloud.github.io/helm-charts
   
   helm install myproxy kubeblocks/apecloud-mysql-cluster --set mode=raftGroup,proxyEnabled=true,etcd.serviceReference.endpoint="etcd-cluster-etcd.default.svc.cluster.local:2379"

4. Check the status of the clusters.

   kbcli get cluster
   
   kbcli get pods

   You can also enter the etcd container or wesql-scale container to view the configuration of wesql-scale or to check the availability of the etcd service.

   etcdctl --endpoints=http://etcd-cluster-etcd.default.svc.cluster.local:2379 get /vitess --prefix --keys-only

kubectl

1. Add the KubeBlocks repository.

   helm repo add kubeblocks https://apecloud.github.io/helm-charts

2. View the repository list to verify whether the KubeBlocks repository is added successfully.

   helm repo list

3. Run the update command to make sure you have added the latest version.

   helm repo update

4. Install etcd to create the external service reference.

   1. View all versions of etcd.

      helm search repo kubeblocks/etcd --devel --versions

   2. Install the etcd Addon.

      helm install etcd kubeblocks/etcd --version=v0.6.5

   3. Install the etcd cluster.

      helm install etcd-cluster kubeblocks/etcd-cluster 

   4. view the status of the etcd cluster and make sure it is running.

      kubectl get cluster
      >
      NAME           CLUSTER-DEFINITION   VERSION       TERMINATION-POLICY   STATUS      AGE
      etcd-cluster   etcd                 etcd-v3.5.6   Halt                 Running     10s

   5. View the service address of this etcd clsuter.

      kubectl get service
      >
      NAME                             TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                                                  AGE
      etcd-cluster-etcd                ClusterIP   10.110.23.89   <none>        2379/TCP                                                 55s
      etcd-cluster-etcd-headless       ClusterIP   None           <none>        2379/TCP,2380/TCP,3501/TCP,50001/TCP                     55s
      kubernetes                       ClusterIP   10.96.0.1      <none>        443/TCP                                                  13m

      You can combine the service address to get the endpoint or you can use the IP of the service address as the access address.

      Here is an example of combining the service address.

      etcd-cluster-etcd.default.svc.cluster.local:2379

5. Create an ApeCloud MySQL Proxy Cluster.

   1. View all versions of ApeCloud MySQL Proxy.

      helm search repo kubeblocks/apecloud-mysql --devel --versions

   2. (Optional) If you disable the apecloud-mysql Addon when installing KuebBlocks, run the command below to specify a version and install the cluster definition of ApeCloud MySQL. Skip this step if you install KubeBlocks with the default settings.

      helm install myproxy kubeblocks/apecloud-mysql --version=v0.9.0

   3. Create an ApeCloud MySQL Proxy Cluster.

      helm install myproxy kubeblocks/apecloud-mysql-cluster --version=v0.9.0 --set mode=raftGroup,proxyEnabled=true,etcd.serviceReference.endpoint="etcd-cluster-etcd.default.svc.cluster.local:2379"

note

If you only have one node for deploying a RaftGroup Cluster, set the extra.availabilityPolicy as none when creating a RaftGroup Cluster.

helm install myproxy kubeblocks/apecloud-mysql-cluster --version=v0.9.0 --set mode=raftGroup,proxyEnabled=true,etcd.serviceReference.endpoint="etcd-cluster-etcd.default.svc.cluster.local:2379" --set extra.availabilityPolicy=none

6. Check the status of the clusters.

   kubectl get cluster
   
   kubectl get pods

   You can also enter the etcd container or wesql-scale container to view the configuration of wesql-scale or to check the availability of the etcd service.

   etcdctl --endpoints=http://etcd-cluster-etcd.default.svc.cluster.local:2379 get /vitess --prefix --keys-only

Enable/Disable Proxy dynamically

As its name suggests, ApeCloud MySQL Proxy in nature is a database proxy. An ApeCloud MySQL RaftGroup Cluster that already exists can be switched to an ApeCloud MySQL Proxy Cluster by setting proxyEnabled=true.

helm upgrade mycluster kubeblocks/apecloud-mysql-cluster --set mode=raftGroup,proxyEnabled=true,etcd.serviceReference.endpoint="etcd-cluster-etcd.default.svc.cluster.local:2379"

If you want to disable proxy, run the command below.

helm upgrade mycluster kubeblocks/apecloud-mysql-cluster --set mode=raftGroup

Connect Proxy Cluster

ApeCloud MySQL Proxy is routed through the vtgate component, and the way the MySQL Server accesses vtgate is similar to the way of accessing mysqld. The external SQL access address provided by ApeCloud MySQL Proxy is the vtgate address and port. The vtgate address created by KubeBlocks by default is myproxy-cluster-vtgate-headless, and the port number is 15306. You can visit ApeCloud MySQL Proxy through the MySQL Server in any pod under the same namespace as ApeCloud MySQL Proxy.

Connect Proxy Cluster by VTGate

kbcli

Run the command below to connect to the Proxy Cluster.

kbcli cluster connect myproxy --components vtgate

kubectl

1. Expose the port of VTGate to the localhost so that the localhost can access the Proxy.

   kubectl port-forward svc/vt-vtgate-headless 15306:15306

2. Connect to the cluster.

   mysql -h 127.0.0.1 -P 15306

Connect Proxy Cluster by MySQL Server

kbcli

Run the command below to connect to the MySQL Server.

kbcli cluster connect myproxy

kubectl

1. Expose the port of the MySQL Server to the localhost so that the localhost can access the MySQL Server.

   kubectl port-forward svc/vt-mysql 3306:3306

2. Connect to the cluster.

   mysql -h 127.0.0.1 -P 3306

note

If you need to test the failover of MySQL, you need to delete the Pod first and continue to port-forward the port, and you can also write a shell script. Here are examples.

For VTGate,

while true; do date; kubectl port-forward svc/vt-vtgate-headless 15306:15306; sleep 0.5; done

For the MySQL Server,

while true; do date; kubectl port-forward svc/vt-mysql 3306:3306; sleep 0.5; done

Configure Proxy Cluster parameters

kbcli

VTGate, VTConsensus, and VTTablet support parameter configuration. You can configure VTGate and VTConsensus by using --components to specify a component and configure VTTablet by using --components=mysql --config-specs=vttablet-config to specify both a component and a configuration file template since VTTablet is the sidecar of the MySQL component.

View parameter details

• View the details of the current configuration file.

  # vtgate
  kbcli cluster describe-config myproxy --components vtgate --show-detail
  
  # vtcontroller
  kbcli cluster describe-config myproxy --components vtcontroller --show-detail
  
  # vttablet
  kbcli cluster describe-config myproxy --components mysql --show-detail --config-specs vttablet-config

• View the parameter descriptions.

  # vtgate
  kbcli cluster explain-config myproxy --components vtgate
  
  # vttablet
  kbcli cluster explain-config myproxy --components mysql --config-specs=vttablet-config

• View the definition of a specified parameter.

  kbcli cluster explain-config myproxy --components vtgate --param=healthcheck_timeout

Reconfigure parameters

1. View the current values in the MySQL Server.

   kbcli cluster connect myproxy --components=vtgate

   mysql> show variables like '%healthcheck_timeout%';

   mysql> show variables like '%health_check_interval%';

2. Configure the healthcheck_timeout for VTGate and the health_check_interval for VTTablet.

   You can use --set flag or edit the parameter configuration file to edit values.

   • By using --set flag

     # vtgate
     kbcli cluster configure myproxy --components vtgate --set=healthcheck_timeout=2s
     
     # vttablet
     kbcli cluster configure myproxy --set=health_check_interval=4s --components=mysql --config-spec=vttablet-config

   • By editing the parameter configuration file

     kbcli cluster edit-config myproxy --components vtgate
     note

     After the vtgate parameter values configuration command is executed, a new vtgate Pod is started and the old vtgate Pod is terminated. You can run the command below to monitor whether the old Pod is terminated.

     kubectl get pod <vtgate-pod-name> -w

3. Use the output command to view the configuration status. For example,

   kbcli cluster describe-ops myproxy -reconfiguring-lth8d -n default
   note

   For more information about parameter configuration, refer to Configuration.

Edit Config File

1. Get the configuration file of this cluster.

   kubectl edit configurations.apps.kubeblocks.io myproxy-vtgate

2. Configure parameters according to your needs. The example below adds the spec.configFileParams part to configure max_connections.

   spec:
     clusterRef: myproxy
     componentName: vtgate
     configItemDetails:
     - configFileParams:
         vtgate.cnf:
           parameters:
             healthcheck_timeout: "5s"
       configSpec:
         constraintRef: mysql-scale-vtgate-config-constraints
         name: vtgate-config
         namespace: kb-system
         templateRef: vtgate-config-template
         volumeName: mysql-scale-config
       name: vtgate-config
       payload: {}

3. Connect to this cluster to verify whether the configuration takes effect.

   1. Expose the port of the MySQL Server to the localhost so that the localhost can access the MySQL Server.

      kubectl port-forward svc/vt-vtgate-headless 15306:15306

   2. Connect to this cluster and verify whether the parameters are configured as expected.

      mysql -h 127.0.0.1 -P 3306
      
      >
      mysql> show variables like 'healthcheck_timeout';
      +---------------------+-------+
      | Variable_name       | Value |
      +---------------------+-------+
      | healthcheck_timeout |  5s   |
      +---------------------+-------+
      1 row in set (0.00 sec)

OpsRequest

Apply an OpsRequest to the specified cluster. Configure the parameters according to your needs.

• An example of configuring VTTablet

  apiVersion: apps.kubeblocks.io/v1alpha1
  kind: OpsRequest
  metadata:
    name: acmysql-vttablet-reconfiguring
    namespace: default
  spec:
    clusterName: acmysql-cluster
    force: false
    reconfigure:
      componentName: mysql
      configurations:
        - keys:
            - key: vttablet.cnf
              parameters:
                - key: health_check_interval
                  value: 4s
          name: vttablet-config
    preConditionDeadlineSeconds: 0
    type: Reconfiguring

• An example of configuring VTGate

  apiVersion: apps.kubeblocks.io/v1alpha1
  kind: OpsRequest
  metadata:
    name: acmysql-vtgate-reconfiguring
    namespace: default
  spec:
    clusterName: acmysql-cluster
    force: false
    reconfigure:
      componentName: vtgate
      configurations:
      - keys:
        - key: vtgate.cnf
          parameters:
          - key: healthcheck_timeout
            value: 2s
        name: vtgate-config
    preConditionDeadlineSeconds: 0
    type: Reconfiguring

Log

You can view the log files of components, Pods, and containers by both kbcli and kubectl.

kbcli

View the log of different components.

kbcli cluster list-logs myproxy
kbcli cluster list-logs myproxy --components vtgate
kbcli cluster list-logs myproxy --components vtcontroller
kbcli cluster list-logs myproxy --components mysql

View the log of a Pod.

kbcli cluster logs myproxy --instance myproxy-vtgate-85bdcf99df-wbmnl

View the log of a container in a Pod.

kbcli cluster logs myproxy --instance myproxy-mysql-0 -c vttablet

kubectl

View the log of VTGate.

kubectl logs myproxy-cluster-vtgate-8659d5db95-4dzt5

View the log of VTTablet and -c is required.

kubectl logs myproxy-cluster-mysql-0 -c vttablet

Enter the container and view more logs of VTGate.

kubectl exec -it myproxy-cluster-vtgate-8659d5db95-4dzt5 -- bash
ls /vtdataroot

Enter the container and view more logs of VTTablet.

kubectl exec -it myproxy-cluster-mysql-0  -c vttablet -- bash
ls /vtdataroot

Monitoring

note

In the production environment, all monitoring Addons are disabled by default when installing KubeBlocks. You can enable these Addons but it is highly recommended to build your monitoring system or purchase a third-party monitoring service. For details, refer to Monitoring.

kbcli

1. Enable the monitoring function.

   kbcli cluster update myproxy --disable-exporter=false

2. View the Addon list and enable the Grafana Addon.

   kbcli addon list 
   
   kbcli addon enable grafana

3. View the dashboard list.

   kbcli dashboard list

4. Open the Grafana dashboard.

   kbcli dashboard open kubeblocks-grafana

kubectl

1. Enable the monitoring Addons.

   For the testing/demo environment, run the commands below to enable the monitoring Addons provided by KubeBlocks.

   helm install prometheus kubeblocks/prometheus --namespace kb-system --create-namespace
   helm install prometheus kubeblocks/prometheus --namespace kb-system --create-namespace
   helm install prometheus kubeblocks/prometheus --namespace kb-system --create-namespace

   For the production environment, you can integrate the monitoring components. For details, you can refer to the relevant docs provided by the monitoring tools.

2. Check whether the monitoring function of this proxy cluster is enabled.

   kubectl get cluster myproxy -o yaml

   If the output YAML file shows disableExporter: false, the monitoring function of this proxy cluster is enabled.

   If the monitoring function is not enabled, run the command below to enable it first.

   kubectl patch cluster mycluster -n demo --type "json" -p '[{"op":"add","path":"/spec/componentSpecs/0/disableExporter","value":false}]'

3. View the dashboard.

   For the testing/demo environment, run the commands below to view the Grafana dashboard.

   # 1. Get the username and password 
   kubectl get secret grafana -n kb-system -o jsonpath='{.data.admin-user}' |base64 -d
   
   kubectl get secret grafana -n kb-system -o jsonpath='{.data.admin-password}' |base64 -d
   
   # 2. Connect to the Grafana dashboard
   kubectl port-forward svc/grafana -n kb-system 3000:8
   
   # 3. Open the web browser and enter the address 127.0.0.1:3000 to visit the dashboard.
   
   # 4. Enter the username and password obtained from step 1.

   For the production environment, you can view the dashboard of the corresponding cluster via Grafana Web Console. For more detailed information, see the Grafana dashboard documentation.

note

1. If there is no data in the dashboard, you can check whether the job is kubeblocks-service. Enter kubeblocks-service in the job field and press the enter button.

   

2. For more details on the monitoring function, you can refer to Monitoring.

Read-write splitting

You can enable the read-write splitting function.

kbcli

kbcli cluster configure myproxy --components vtgate --set=read_write_splitting_policy=random

You can also set the ratio for read-write splitting and here is an example of directing 70% flow to the read-only node.

kbcli cluster configure myproxy --components vtgate --set=read_write_splitting_ratio=70

Moreover, you can use Grafana or run show workload in the VTGate terminal to view the flow distribution.

show workload;

kubectl

1. Get the configuration file of this cluster.

   kubectl edit configurations.apps.kubeblocks.io myproxy-vtgate

2. Configure read_write_splitting_policy as random.

   spec:
     clusterRef: myproxy
     componentName: vtgate
     configItemDetails:
     - configFileParams:
         vtgate.cnf:
           parameters:
             read_write_splitting_policy: "random"
       configSpec:
         constraintRef: mysql-scale-vtgate-config-constraints
         name: vtgate-config
         namespace: kb-system
         templateRef: vtgate-config-template
         volumeName: mysql-scale-config
       name: vtgate-config
       payload: {}

You can also set the ratio for read-write splitting and here is an example of directing 70% flow to the read-only node.

spec:
   clusterRef: myproxy
   componentName: vtgate
   configItemDetails:
   - configFileParams:
      vtgate.cnf:
         parameters:
            read_write_splitting_rati: "70"
      configSpec:
      constraintRef: mysql-scale-vtgate-config-constraints
      name: vtgate-config
      namespace: kb-system
      templateRef: vtgate-config-template
      volumeName: mysql-scale-config
      name: vtgate-config
      payload: {}

Transparent failover

kbcli

Run the command below to implement transparent failover.

kbcli cluster configure myproxy --components vtgate --set=enable_buffer=true

kubectl

1. Get the configuration file of this cluster.

   kubectl edit configurations.apps.kubeblocks.io myproxy-vtgate

2. Configure enable_buffer as true.

   spec:
     clusterRef: myproxy
     componentName: vtgate
     configItemDetails:
     - configFileParams:
         vtgate.cnf:
           parameters:
             enable_buffer: "true"
       configSpec:
         constraintRef: mysql-scale-vtgate-config-constraints
         name: vtgate-config
         namespace: kb-system
         templateRef: vtgate-config-template
         volumeName: mysql-scale-config
       name: vtgate-config
       payload: {}