This page details step 6 of the 7-step procedure "Deploy Primary/Replica Topology".
This step starts and configures MariaDB MaxScale.
Interactive commands are detailed. Alternatively, the described operations can be performed using automation.
MariaDB MaxScale installations include a configuration file with some example objects. This configuration file should be replaced.
On the MaxScale node, replace the default /etc/maxscale.cnf with the following configuration:
For additional information, see "".
On the MaxScale node, restart the MaxScale service to ensure that MaxScale picks up the new configuration:
For additional information, see "".
On the MaxScale node, use server to create a server object for each MariaDB Enterprise Server:
MaxScale uses monitors to retrieve additional information from the servers. This information is used by other services in filtering and routing connections based on the current state of the node. For MariaDB Replication, use the MariaDB Monitor (mariadbmon).
On the MaxScale node, use to create a MariaDB Monitor:
In this example:
mdb_monitor is an arbitrary name that is used to identify the new monitor.
mariadbmon is the name of the module that implements the MariaDB Monitor.
user=MAXSCALE_USER sets the user parameter to the database user account that MaxScale uses to monitor the ES nodes.
Routers control how MaxScale balances the load between Enterprise Server nodes. Each router uses a different approach to routing queries. Consider the specific use case of your application and database load and select the router that best suits
Use MaxScale Read Connection Router (readconnroute) to route connections to replica servers for a read-only pool.
On the MaxScale node, use maxctrl create service to create a router:
In this example:
connection_router_service is an arbitrary name that is used to identify the new service.
readconnroute is the name of the module that implements the Read Connection Router.
user=MAXSCALE_USER sets the user parameter to the database user account that MaxScale uses to connect to the ES nodes.
These instructions reference TCP port 3308. You can use a different TCP port. The TCP port used must not be bound by any other listener.
On the MaxScale node, use the maxctrl create listener command to configure MaxScale to use a listener for the Read Connection Router (readconnroute):
In this example:
connection_router_service is the name of the readconnroute service that was previously created.
connection_router_listener is an arbitrary name that is used to identify the new listener.
3308 is the TCP port.
MaxScale Read/Write Split Router (readwritesplit) performs query-based load balancing. The router routes write queries to the primary and read queries to the replicas.
On the MaxScale node, use the maxctrl create service command to configure MaxScale to use the Read/Write Split Router (readwritesplit):
In this example:
query_router_service is an arbitrary name that is used to identify the new service.
readwritesplit is the name of the module that implements the Read/Write Split Router.
user=MAXSCALE_USER sets the user parameter to the database user account that MaxScale uses to connect to the ES nodes.
These instructions reference TCP port 3307. You can use a different TCP port. The TCP port used must not be bound by any other listener.
On the MaxScale node, use the maxctrl create listener command to configure MaxScale to use a listener for the Read/Write Split Router (readwritesplit):
In this example:
query_router_service is the name of the readwritesplit service that was previously created.
query_router_listener is an arbitrary name that is used to identify the new listener.
3307 is the TCP port.
To start the services and monitors, on the MaxScale node use maxctrl start services:
Navigation in the procedure "Deploy Primary/Replica Topology":
This page was step 6 of 7.
Next: Step 7: Test MariaDB MaxScale
password='MAXSCALE_USER_PASSWORD' sets the password parameter to the password used by the database user account that MaxScale uses to monitor the ES nodes.
replication_user=REPLICATION_USER sets the replication_user parameter to the database user account that MaxScale uses to setup replication.
replication_password='REPLICATION_USER_PASSWORD' sets the replication_password parameter to the password used by the database user account that MaxScale uses to setup replication.
--servers sets the servers parameter to the set of nodes that MaxScale should monitor. All non-option arguments after --servers are interpreted as server names.
Other Module Parameters supported by mariadbmon in MaxScale can also be specified.
password=MAXSCALE_USER_PASSWORD sets the password parameter to the password used by the database user account that MaxScale uses to connect to the ES nodes.
router_options=slave sets the router_options parameter to slave, so that MaxScale only routes connections to the replica nodes.
--servers sets the servers parameter to the set of nodes to which MaxScale should route connections. All non-option arguments after --serversare interpreted as server names.
Other Module Parameters supported by readconnroute in MaxScale 25.01 can also be specified.
protocol=MariaDBClient sets the protocol parameter.Other Module Parameters supported by listeners in MaxScale can also be specified.
password=MAXSCALE_USER_PASSWORD sets the password parameter to the password used by the database user account that MaxScale uses to connect to the ES nodes.
--servers sets the servers parameter to the set of nodes to which MaxScale should route queries. All non-option arguments after --servers are interpreted as server names.
Other Module Parameters supported by readwritesplit in MaxScale can also be specified.
protocol=MariaDBClient sets the protocol parameter.Other Module Parameters supported by listeners in MaxScale can also be specified.
Connection-based load balancing
Routes connections to Enterprise ColumnStore nodes designated as replica servers for a read-only pool
Routes connections to an Enterprise ColumnStore node designated as the primary server for a read-write pool.
Query-based load balancing
Routes write queries to an Enterprise ColumnStore node designated as the primary server
Routes read queries to Enterprise ColumnStore node designated as replica servers
Automatically reconnects after node failures
Automatically replays transactions after node failures
Optionally enforces causal reads
[maxscale]
threads = auto
admin_host = 0.0.0.0
admin_secure_gui = false$ sudo systemctl restart maxscale$ maxctrl create server node1 192.0.2.101
$ maxctrl create server node2 192.0.2.102
$ maxctrl create server node3 192.0.2.103$ maxctrl create monitor mdb_monitor mariadbmon \
user=mxs \
password='MAXSCALE_USER_PASSWORD' \
replication_user=repl \
replication_password='REPLICATION_USER_PASSWORD' \
--servers node1 node2 node3$ maxctrl create service connection_router_service readconnroute \
user=mxs \
password='MAXSCALE_USER_PASSWORD' \
router_options=slave \
--servers node1 node2 node3$ maxctrl create listener connection_router_service connection_router_listener 3308 \
protocol=MariaDBClient$ maxctrl create service query_router_service readwritesplit \
user=mxs \
password='MAXSCALE_USER_PASSWORD' \
--servers node1 node2 node3$ maxctrl create listener query_router_service query_router_listener 3307 \
protocol=MariaDBClient$ maxctrl start servicesThis page is: Copyright © 2025 MariaDB. All rights reserved.