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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.x.x'

    Or if you already have a Kubernetes cluster, you can install KubeBlocks 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.

  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 User addons 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

Enable Proxy dynamically​

As its name suggests, ApeCloud MySQL Proxy in nature is a database proxy. An ApeCloud MySQL RaftGroup Cluster 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

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​

Run the command below to connect to the Proxy Cluster.

kbcli cluster connect myproxy --components vtgate

Connect Proxy Cluster by MySQL Server​

Run the command below to connect to the MySQL Server.

kbcli cluster connect myproxy
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​

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-detai

    # 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.

Log​

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

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

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.

  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

Read-write splitting​

You can enable the read-write splitting function.

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 to view the flow distribution.

show workload;

Transparent failover​

Run the command below to implement transparent failover.

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