k8s-proxysql-cluster

Container to run proxysql in cluster mode in kubernetes.

Usage

By default te the container acts as a normal proxysql instance. To enable cluster mode the following is needed.

Service

the container uses a service to discover if there are already master nodes up. This service can be found in

/k8s/proxysql.service.yaml

use the following command to use the service in kubernetes

kubectl create -f ./k8s/proxysql.service.yaml

Statefulset

To deploy the actual nodes a statefulset should be added to the kubernetes cluster This statefulset can be found in

/k8s/proxysql.statefulset.yaml

use the following command to use the statefulset in kubernetes

kubectl create -f ./k8s/proxysql.statefulset.yaml

Helm Install

You can install using the helm repository using the following command:

helm install --name db-proxy deploy/charts/proxysql-cluster 

Parameter	Description	Default
image.repository	proxysql image repo	scienta/k8s-proxysql-cluster
image.tag	proxysql image tag	1.0.0
numReplicas	Number of replicas to create in StatefulSet	3
proxysql.admin.username	Admin username for proxysql	admin
proxysql.admin.password	Admin password for proxysql	admin
proxysql.admin.iface	Listen network for proxysql service	0.0.0.0
proxysql.admin.port	Listen port for proxysql service	6032
proxysql.clusterAdmin.username	Cluster user username used by proxysql nodes to sync	cluster1
proxysql.clusterAdmin.password	Cluster user password used by proxysql nodes to sync	secret1pass
proxysql.queryCacheSizeMb	(Optional) Query cache size	nil
proxysql.dataDir	Directory to store proxysql tables, etc.	/var/lib/proxysql
proxysql.webEnabled	Enable proxysql web dashboard	true
mysql.iface	Listen network for mysql service connections	0.0.0.0
mysql.port	Listen port fo mysql service connections	3306
mysql.monitor.username	Monitor username on MySQL instances for proxysql health checks	monitor
mysql.monitor.password	Monitor password on MySQL instances for proxysql health checks	monitor
mysql.admin.username	Root / admin username on MySQL instances	root
mysql.admin.password	Root / admin password on MySQL instances	insecurepassword
cronjob.enabled	Enable k8s CronJob to set the default hostgroup to the backend having the least # databases	false
resources	CPU / Memory Limits and Requests	{}
tolerations	Pod tolerations	'{}'

Workings

When the container is run with the --k8s-cluster argument the following happens:

• the container checks if there is a node available at the proxysql service

• If no node is available this container becomes the first master node of the cluster

  • The node deletes the proxysql server from the proxysql_servers table
  • The node adds its own ip to its proxysql_servers table

• Else the node wil join the existing master nodes

  • The node's proxysql_servers table is synced with that of the existing master nodes
  • The node adds its own ip to the proxysql_servers table of the node exposed by the proxysql service.
  • The node deletes the proxysql service from the proxysql_servers table

• The cluster is up and running!