MaxScale 21.06 Connection Routing with MariaDB MaxScale
Connection Routing with MariaDB MaxScale
The goal of this tutorial is to configure a system that has two ports available, one for write connections and another for read connections. The read connections are load- balanced across slave servers.
Setting up MariaDB MaxScale
This tutorial is a part of the MariaDB MaxScale Tutorial. Please read it and follow the instructions. Return here once basic setup is complete.
Configuring services
We want two services and ports to which the client application can connect. One service routes client connections to the master server, the other load balances between slave servers. To achieve this, we need to define two services in the configuration file.
Create the following two sections in your configuration file. The section names are the names of the services and should be meaningful. For this tutorial, we use the names Write-Service and Read-Service.
[Write-Service] type=service router=readconnroute router_options=master servers=dbserv1, dbserv2, dbserv3 user=maxscale password=maxscale_pw [Read-Service] type=service router=readconnroute router_options=slave servers=dbserv1, dbserv2, dbserv3 user=maxscale password=maxscale_pw
router defines the routing module used. Here we use readconnroute for connection-level routing.
A service needs a list of servers to route queries to. The server names must match the names of server sections in the configuration file and not the hostnames or addresses of the servers.
The router_options-parameter tells the readconnroute-module which servers it should route a client connection to. For the write service we use the master-type and for the read service the slave-type.
The user and password parameters define the credentials the service uses to populate user authentication data. These users were created at the start of the MaxScale Tutorial.
For increased security, see password encryption.
Configuring the Listener
To allow network connections to a service, a network ports must be associated with it. This is done by creating a separate listener section in the configuration file. A service may have multiple listeners but for this tutorial one per service is enough.
[Write-Listener] type=listener service=Write-Service protocol=MariaDBClient port=3306 [Read-Listener] type=listener service=Read-Service protocol=MariaDBClient port=3307
The service parameter tells which service the listener connects to. For the Write-Listener we set it to Write-Service and for the Read-Listener we set it to Read-Service.
A listener must define the protocol module it uses. This must be MariaDBClient for all database listeners. port defines the the network port to listen on.
The optional address-parameter defines the local address the listener should bind to.
This may be required when the host machine has multiple network interfaces. The
default behavior is to listen on all network interfaces (the IPv6 address ::
).
Starting MariaDB MaxScale
For the last steps, please return to MaxScale Tutorial.