Deploy MaxScale 2.5 on SLES 15 with MariaDB Monitor and Read/Write Split Router
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These instructions detail the deployment of MariaDB MaxScale 2.5 on SUSE Linux Enterprise Server 15 in a MaxScale Instance with MariaDB Monitor and Read/Write Split Router.
These instructions detail how to deploy MariaDB MaxScale as a load balancing and high availability solution for MariaDB Replication.
Prerequisites
These instructions assume that the back-end MariaDB Server instances have already been deployed.
See the following resources for how to deploy Primary and Replica servers:
MariaDB Platform Components
These instructions detail the deployment of the following MariaDB Platform components:
Component |
Description |
---|---|
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MaxScale Components
These instructions detail the deployment of MaxScale with the following components:
Component |
Description |
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Term Definitions
Term |
Definition |
---|---|
MaxScale instance |
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Installation
MariaDB Corporation provides a ZYpp package repository for SUSE Linux Enterprise Server 15.
Install via ZYpp (SLES)
Retrieve your Customer Download Token at https://customers.mariadb.com/downloads/token/ and substitute for
customer_download_token
in the following directions.Configure the ZYpp package repository.
To configure ZYpp package repositories:
$ sudo zypper install wget $ wget https://dlm.mariadb.com/enterprise-release-helpers/mariadb_es_repo_setup $ echo "c78db828709d94876406a0ea346f13fbc38e73996795903f40e3c21385857dd4 mariadb_es_repo_setup" \ | sha256sum -c - $ chmod +x mariadb_es_repo_setup $ sudo ./mariadb_es_repo_setup --token="customer_download_token" --apply \ --mariadb-maxscale-version="2.5"
Install MariaDB MaxScale and package dependencies:
$ sudo zypper install maxscale
Configure MaxScale.
Installation only loads MariaDB MaxScale to the system. MariaDB MaxScale requires configuration before MaxScale is ready for use.
See Configuration.
Configuration
MariaDB MaxScale's parameters can be configured in two ways:
All parameters can be set in a configuration file (such as the
/etc/maxscale.cnf
file). When the configuration file is updated, the MaxScale instance must be restarted to apply the changes.If a parameter supports dynamic changes, it can be set on-the-fly using the MaxCtrl utility.
Configuring MaxScale's Global Parameters
Determine which global parameters you need to configure.
Useful global parameters for MariaDB MaxScale:
Parameter
Description
Sets the local IP address or network interface to use when connecting to MariaDB Enterprise Servers.
Sets whether the MaxScale Instance supports the REST API. Disable to block access.
Sets the network interface used by the REST API.
Sets the port used by the REST API.
Sets whether the REST API uses HTTP Basic Access authentication. Users can be created wih maxctrl.
Set your global parameters in
maxscale.cnf
.MariaDB MaxScale's global parameters, which apply to the whole instance, are set in the
[maxscale]
configuration group:For example:
[maxscale] admin_auth = true
Configuring Servers
Determine which server parameters you need to configure.
Mandatory parameters for Server objects:
Parameter
Description
type
Set the module type to
server
.address
Set the IP address for the MariaDB Enterprise Server.
port
Set the port the MariaDB Enterprise Server listens on.
protocol
Set the protocol to
MariaDBBackend
to connect the Server.Set your server parameters in
maxscale.cnf
.For each Server in your deployment, add a new uniquely-named configuration group to the MaxScale Instance. The name of the configuration group is arbitrary, but it cannot contain any white space. Use whatever terms you find most convenient, but it is most common to use names like
serverN
or the server's host name.For example:
[server1] type = server address = 192.0.2.2 port = 3306 protocol = MariaDBBackend
Configuring MariaDB Monitor
Determine which parameters for MariaDB Monitor (mariadbmon) you need to configure.
Mandatory parameters for MariaDB Monitor (
mariadbmon
):Parameter
Description
type
Set the type to
monitor
.module
Set to
mariadbmon
for MariaDB Replication.servers
Set to a comma-separated list of the Server object names.
user
Set to the user MariaDB MaxScale uses to connect to the Servers.
password
Set to the password MariaDB MaxScale uses to authenticate on the Servers.
Useful parameters for MariaDB Monitor (
mariadbmon
):Parameter
Description
auto_failover
Enables Automatic Failover for MariaDB Replication deployments, allowing the monitor to respond to a master server failure by reconfiguring a replica server to operate as the new master server.
auto_rejoin
Enables Automatic Rejoin for MariaDB Replication deployments, allowing the monitor to reconfigure replica servers that were down during Automatic Failover to use the new master server.
Set your MariaDB Monitor parameters in
maxscale.cnf
.Add a new uniquely-named configuration group for the monitor to the MaxScale Instance. The name of the configuration group is arbitrary, but it cannot contain any white space. Use whatever terms you find most convenient, but it is most common to use names like
repl-monitor
.For example:
[repl-monitor] type = monitor module = mariadbmon servers = server1,server2,server3 user = maxscale password = max_passwd auto_failover = ON auto_rejoin = ON
Configuring Read/Write Split Router
Determine which parameters for Read/Write Split Router (readwritesplit) you need to configure.
Mandatory parameters for Read/Write Split Router (
readwritesplit
):Parameter
Description
type
Set the module type as
service
.router
Use to set the type of router you want to use for the service. For the Read/Write Split router, set to
readwritesplit
.servers
Set as a comma-separated list of the Server object names.
user
Set the user you want the MaxScale Instance to use when connecting to Servers.
password
Set the password you want the MaxScale Instance to use in authentication when conecting to Servers.
Set your Read/Write Split Router parameters in
maxscale.cnf
.Add a new uniquely-named configuration group for the router to the MaxScale Instance. The name of the configuration group is arbitrary, but it cannot contain any white space. Use whatever terms you find most convenient, but it is most common to use names like
split-router
.For example:
[split-router] type = service router = readwritesplit servers = server1,server2,server3 user = maxscale password = max_passwd
Configuring the Router's Listener
Determine which parameters for the listener you need to configure.
Mandatory parameters for the listener:
Parameter
Description
type
Set the module type as a
listener
.service
Use this parameter to connect the listener to a configured routing service.
protocol
Set this parameter to
MariaDBClient
to handle incoming client connections.port
Set this parameter to specify the port you want the MaxScale Instance to listen on.
Set your listener parameters in
maxscale.cnf
.Add a new uniquely-named configuration group for the listener to the MaxScale Instance. The name of the configuration group is arbitrary, but it cannot contain any white space. Use whatever terms you find most convenient, but it is most common to use names like
split-router-listener
.For example:
[split-router-listener] type = listener service = split-router protocol = MariaDBClient port = 3306
Configuring the User Account
On each back-end MariaDB server, create the user account used by the monitor and the router using the CREATE USER statement. Make sure that the user account can connect from the MaxScale instance's IP address:
CREATE USER 'maxscale'@'192.0.2.1' IDENTIFIED BY 'max_passwd';
On each back-end MariaDB server, grant the required privileges to the user account used by the monitor and the router using the GRANT statement.
For the Read/Write Split Router (readwritesplit) , the global
SHOW DATABASES
privilege and theSELECT
privilege on several of the system's privilege tables are required:GRANT SHOW DATABASES ON *.* TO 'maxscale'@'192.0.2.1'; GRANT SELECT ON mysql.columns_priv TO 'maxscale'@'192.0.2.1'; GRANT SELECT ON mysql.db TO 'maxscale'@'192.0.2.1'; GRANT SELECT ON mysql.proxies_priv TO 'maxscale'@'192.0.2.1'; GRANT SELECT ON mysql.roles_mapping TO 'maxscale'@'192.0.2.1'; GRANT SELECT ON mysql.tables_priv TO 'maxscale'@'192.0.2.1'; GRANT SELECT ON mysql.user TO 'maxscale'@'192.0.2.1';
For MariaDB Monitor (mariadbmon), the required permissions depend on the version of MariaDB Enterprise Server that is being used.
In ES10.5.8-5 and later, the following privileges are required:
GRANT BINLOG ADMIN, READ_ONLY ADMIN, RELOAD, REPLICA MONITOR, REPLICATION MASTER ADMIN, REPLICATION REPLICA ADMIN, REPLICATION REPLICA, SHOW DATABASES ON *.* TO 'maxscale'@'192.0.2.1';
In ES10.5.6-4 and before, the following privileges are required:
GRANT BINLOG ADMIN, BINLOG MONITOR, READ_ONLY ADMIN, RELOAD, REPLICATION MASTER ADMIN, REPLICATION REPLICA ADMIN, REPLICATION REPLICA, SHOW DATABASES ON *.* TO 'maxscale'@'192.0.2.1';
In ES10.4 and before, the following privileges are required:
GRANT SUPER, REPLICATION CLIENT, RELOAD, PROCESS, SHOW DATABASES, EVENT ON *.* TO 'maxscale'@'192.0.2.1';
Starting the MaxScale Instance
MariaDB MaxScale installations include configuration to start, stop, restart, enable/disable on boot, and check the status of the MaxScale Instance using the operating system default process management system.
SUSE Linux Enterprise Server 15 uses systemd. You can manage the MaxScale process using the systemctl
command:
Operation |
Command |
Start |
|
Stop |
|
Restart |
|
Enable during startup |
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Disable during startup |
|
Status |
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Testing
When you have MariaDB MaxScale up and running, you should test it to ensure that it is working and that weren't any issues during startup.
Checking MaxScale Status
Check that MaxScale is running properly by using the MaxCtrl utility:
$ sudo maxctrl show maxscale ┌──────────────┬──────────────────────────────────────────────────────────────────────┐ │ Version │ 2.5.8 │ ├──────────────┼──────────────────────────────────────────────────────────────────────┤ │ Commit │ 61b8bbf7f63c38ca9c408674e66f3627a0b2192e │ ├──────────────┼──────────────────────────────────────────────────────────────────────┤ │ Started At │ Fri, 03 Jan 2020 18:05:18 GMT │ ├──────────────┼──────────────────────────────────────────────────────────────────────┤ │ Activated At │ Fri, 03 Jan 2020 18:05:18 GMT │ ├──────────────┼──────────────────────────────────────────────────────────────────────┤ │ Uptime │ 109 │ ├──────────────┼──────────────────────────────────────────────────────────────────────┤ │ Parameters │ { │ │ │ "libdir": "/usr/lib/x86_64-linux-gnu/maxscale", │ │ │ "datadir": "/var/lib/maxscale", │ │ │ "process_datadir": "/var/lib/maxscale/data3850", │ │ │ "cachedir": "/var/cache/maxscale", │ │ │ "configdir": "/etc", │ │ │ "config_persistdir": "/var/lib/maxscale/maxscale.cnf.d", │ │ │ "module_configdir": "/etc/maxscale.modules.d", │ │ │ "piddir": "/var/run/maxscale", │ │ │ "logdir": "/var/log/maxscale", │ │ │ "langdir": "/var/lib/maxscale", │ │ │ "execdir": "/usr/bin", │ │ │ "connector_plugindir": "/usr/lib/x86_64-linux-gnu/mysql/plugin", │ │ │ "threads": 1, │ │ │ "thread_stack_size": 8388608, │ │ │ "writeq_high_water": 0, │ │ │ "writeq_low_water": 0, │ │ │ "auth_connect_timeout": 3, │ │ │ "auth_read_timeout": 1, │ │ │ "auth_write_timeout": 2, │ │ │ "skip_permission_checks": false, │ │ │ "admin_auth": true, │ │ │ "admin_enabled": true, │ │ │ "admin_log_auth_failures": true, │ │ │ "admin_host": "127.0.0.1", │ │ │ "admin_port": 8989, │ │ │ "admin_ssl_key": "", │ │ │ "admin_ssl_cert": "", │ │ │ "admin_ssl_ca_cert": "", │ │ │ "admin_pam_readwrite_service": "", │ │ │ "admin_pam_readonly_service": "", │ │ │ "passive": false, │ │ │ "query_classifier": "", │ │ │ "query_classifier_cache_size": 155008819, │ │ │ "retain_last_statements": 0, │ │ │ "dump_last_statements": "never", │ │ │ "session_trace": 0, │ │ │ "load_persisted_configs": true, │ │ │ "max_auth_errors_until_block": 10 │ │ │ } │ └──────────────┴──────────────────────────────────────────────────────────────────────┘
Testing Load Balancing
In a MariaDB Replication deployment, each MariaDB Enterprise Server has the server_id system variable set to a unique value. You can see what server you are connected to by querying this variable:
SELECT @@server_id AS "Server ID";
+-----------+
| Server ID |
+-----------+
| 2 |
+-----------+
We can also use this system variable to test the Read/Write Split Router's load balancing:
Connect to the MaxScale instance using MariaDB Client:
$ mariadb --host=maxscale \ --port=3306 \ --user=myuser \ --password
Create a test table:
CREATE TABLE test.readwrite_test ( id INT PRIMARY KEY AUTO_INCREMENT, write_id INT );
Insert the value of the the server_id system variable to the table using the INSERT statement:
INSERT INTO test.readwrite_test (write_id) VALUES (@@server_id); INSERT INTO test.readwrite_test (write_id) VALUES (@@server_id); INSERT INTO test.readwrite_test (write_id) VALUES (@@server_id);
Read the newly-inserted rows while querying the value of the the server_id system variable again using the SELECT statement:
SELECT readwrite.id AS "Primary Key", current.id AS "Current Server ID", readwrite.write_id AS "Stored Server ID" FROM ( SELECT @@server_id AS id ) AS current INNER JOIN ( SELECT id, write_id FROM test.readwrite_test ) AS readwrite;
The results will show that the primary server's server_id value was written to the table during the INSERT statement, but the replica server's value was read during the SELECT statement:
+-------------+-------------------+------------------+ | Primary Key | Current Server ID | Stored Server ID | +-------------+-------------------+------------------+ | 1 | 2 | 1 | | 2 | 2 | 1 | | 3 | 2 | 1 | +-------------+-------------------+------------------+