Use ProxySQL 1.x.x with ProxySQL Admin¶

ProxySQL version 1.4.x does not natively support Percona XtraDB Cluster and proxysql-admin and requires custom bash scripts to keep track of Percona XtraDB Cluster status: proxysql_galera_checker and proxysql_node_monitor.

Automatic configuration¶

The proxysql package from Percona includes the proxysql-admin tool for configuring Percona XtraDB Cluster nodes with ProxySQL.

Note

The proxysql-admin script is specially developed by Percona to automate the ProxySQL configuration. Bug reports and feature proposals are welcome in the proxysql-admin issue tracking system.

The proxysql-admin tool can only be used for the initial ProxySQL configuration.

To view usage information, run proxysql-admin without any options:

Usage: [ options ]
Options:
--config-file=<config-file>        Read login credentials from a configuration file
                        (command line options override any configuration file login credentials)
--proxysql-datadir=<datadir>       Specify the proxysql data directory location
--proxysql-username=user_name      ProxySQL service username
--proxysql-password[=password]     ProxySQL service password
--proxysql-port=port_num           ProxySQL service port number
--proxysql-hostname=host_name      ProxySQL service hostname
--cluster-username=user_name       Percona XtraDB Cluster node username
--cluster-password[=password]      Percona XtraDB Cluster node password
--cluster-port=port_num            Percona XtraDB Cluster node port number
--cluster-hostname=host_name       Percona XtraDB Cluster node hostname
--cluster-app-username=user_name   Percona XtraDB Cluster node application username
--cluster-app-password[=password]  Percona XtraDB Cluster node application password
--without-cluster-app-user         Configure Percona XtraDB Cluster without application user
--monitor-username=user_name       Username for monitoring Percona XtraDB Cluster nodes through ProxySQL
--monitor-password[=password]      Password for monitoring Percona XtraDB Cluster nodes through ProxySQL
--use-existing-monitor-password    Do not prompt for a new monitor password if one is provided.
--node-check-interval=3000         Interval for monitoring node checker script (in milliseconds)
                                (default: 3000)
--mode=[loadbal|singlewrite]       ProxySQL read/write configuration mode
                                    currently supporting: 'loadbal' and 'singlewrite'
                                    (default: 'singlewrite')
--write-node=host_name:port        Writer node to accept write statments.
                                    This option is supported only when using --mode=singlewrite
                                    Can accept comma-delimited list with the first listed being
                                    the highest priority.
--include-slaves=host_name:port    Add specified slave node(s) to ProxySQL, these nodes will go
                                into the reader hostgroup and will only be put into
                                the writer hostgroup if all cluster nodes are down (this
                                depends on the value of --use-slave-as-writer).
                                Slaves must be read only.  Can accept a comma-delimited list.
                                If used, make sure 'read_only=1' is in the slave's my.cnf
--use-slave-as-writer=<yes/no>     If this value is 'yes', then a slave may be used as a writer
                                if the entire cluster is down. If 'no', then a slave
                                will not be used as a writer. This option is required
                                if '--include-slaves' is used.
--writer-is-reader=<value>         Defines if the writer node also accepts writes.
                                Possible values are 'always', 'never', and 'ondemand'.
                                'ondemand' means that the writer node only accepts reads
                                if there are no other readers.
                                (default: 'ondemand')
--max-connections=<NUMBER>         Value for max_connections in the mysql_servers table.
                                This value is the maximum number of connections that
                                ProxySQL will open to the backend servers.
                                (default: 1000)
--debug                            Enables additional debug logging.
--help                             Displays this help text.

These options are the possible operations for proxysql-admin.
You must provide one of the options.
--adduser                          Adds the Percona XtraDB Cluster application user to the ProxySQL database
--disable, -d                      Remove any Percona XtraDB Cluster configurations from ProxySQL
--enable, -e                       Auto-configure Percona XtraDB Cluster nodes into ProxySQL
--quick-demo                       Setup a quick demo with no authentication
--syncusers                        Sync user accounts currently configured in MySQL to ProxySQL
                                May be used with --enable.
                                (deletes ProxySQL users not in MySQL)
--sync-multi-cluster-users         Sync user accounts currently configured in MySQL to ProxySQL
                                May be used with --enable.
                                (doesn't delete ProxySQL users not in MySQL)
--version, -v                      Print version info

Note

The Percona XtraDB Cluster nodes and ProxySQL must be available before using the proxysql-admin tool. For security purposes, change the default user settings in the ProxySQL configuration file.

Prepare a configuration file¶

We recommend providing the connection and authentication information in the ProxySQL configuration file (/etc/proxysql-admin.cnf), instead of specifying this information on the command line.

By default, the configuration file contains the following:

# proxysql admin interface credentials.
export PROXYSQL_DATADIR='/var/lib/proxysql'
export PROXYSQL_USERNAME='admin'
export PROXYSQL_PASSWORD='admin'
export PROXYSQL_HOSTNAME='localhost'
export PROXYSQL_PORT='6032'

# PXC admin credentials for connecting to pxc-cluster-node.
export CLUSTER_USERNAME='admin'
export CLUSTER_PASSWORD='admin'
export CLUSTER_HOSTNAME='localhost'
export CLUSTER_PORT='3306'

# proxysql monitoring user. proxysql admin script will create this user in pxc to monitor pxc-nodes.
export MONITOR_USERNAME='monitor'
export MONITOR_PASSWORD='monit0r'

# Application user to connect to pxc-node through proxysql
export CLUSTER_APP_USERNAME='proxysql_user'
export CLUSTER_APP_PASSWORD='passw0rd'

# *ProxySQL* read/write hostgroup
export WRITE_HOSTGROUP_ID='10'
export READ_HOSTGROUP_ID='11'

# *ProxySQL* read/write configuration mode.
export MODE="singlewrite"

# Writer-is-reader configuration
export WRITER_IS_READER="ondemand"

# max_connections default (used only when INSERTing a new mysql_servers entry)
export MAX_CONNECTIONS="1000"

Note

We recommend that you change the default ProxySQL credentials before running ProxySQL in production. Make sure that you provide ProxySQL location and credentials in the configuration file. See Do not use the default credentials. Provide superuser credentials for one of the Percona XtraDB Cluster nodes. The proxysql-admin script will detect other nodes in the cluster automatically.

Enabling ProxySQL¶

Use the --enable option to automatically configure a Percona XtraDB Cluster node into ProxySQL. The proxysql-admin tool will do the following:

Add a Percona XtraDB Cluster node into the ProxySQL database
Add the proxysql_galera_checker monitoring script into the ProxySQL scheduler table if it is not available. This script checks for desynced nodes and temporarily deactivates them. It also calls the proxysql_node_monitor script, which checks cluster node membership and re-configures ProxySQL if the membership changes.
Create two new Percona XtraDB Cluster users with the USAGE privilege on the node and add them to ProxySQL configuration if they are not already configured. ProxySQL uses one user for monitoring cluster nodes, and the other one is used for communicating with the cluster. Make sure to use superuser credentials from cluster to set up the default users.

Warning

Running more than one copy of proxysql_galera_check in the same runtime environment simultaneously is not supported and may lead to undefined behavior. To avoid this problem, Galera process identification prevents a duplicate script execution in most cases. However, in some rare cases, it may be possible to circumvent this check if you run more than one copy of proxysql_galera_check.

The following example shows how to add a Percona XtraDB Cluster node using the ProxySQL configuration file with all necessary connection and authentication information:

$ proxysql-admin --config-file=/etc/proxysql-admin.cnf --enable

Expected output

    This script will assist with configuring ProxySQL for use with
    Percona XtraDB Cluster (currently, only PXC in combination with ProxySQL is supported)

    ProxySQL read/write configuration mode is singlewrite

    Configuring the ProxySQL monitoring user.  ProxySQL monitor user name as per
    command line/config-file is monitor

    User 'monitor'@'127.%' has been added with USAGE privileges

    Configuring the Percona XtraDB Cluster application user to connect through ProxySQL
    Percona XtraDB Cluster application user name as per command line/config-file is proxysql_user

    Percona XtraDB Cluster application user 'proxysql_user'@'127.%' has been added with ALL privileges. This user is created for testing purposes.
    Adding the Percona XtraDB Cluster server nodes to ProxySQL

    Write node info

    +-----------+--------------+-------+--------+
    | hostname  | hostgroup_id | port  | weight |
    +-----------+--------------+-------+--------+
    | 127.0.0.1 | 10           | 26100 | 1000   |
    +-----------+--------------+-------+--------+

    ProxySQL configuration completed!

    ProxySQL has been successfully configured to use with Percona XtraDB Cluster

    You can use the following login credentials to connect your application through ProxySQL

    $ mysql --user=proxysql_user -p --host=localhost --port=6033 --protocol=tcp

mysql> select hostgroup_id,hostname,port,status,comment from mysql_servers;

Expected output

  +--------------+-----------+-------+--------+---------+
  | hostgroup_id | hostname  | port  | status | comment |
  +--------------+-----------+-------+--------+---------+
  | 11           | 127.0.0.1 | 25400 | ONLINE | READ    |
  | 10           | 127.0.0.1 | 25000 | ONLINE | WRITE   |
  | 11           | 127.0.0.1 | 25100 | ONLINE | READ    |
  | 11           | 127.0.0.1 | 25200 | ONLINE | READ    |
  | 11           | 127.0.0.1 | 25300 | ONLINE | READ    |
  +--------------+-----------+-------+--------+---------+
  5 rows in set (0.00 sec)

Disabling ProxySQL¶

Use the --disable option to remove a Percona XtraDB Cluster node’s configuration from ProxySQL. The proxysql-admin tool will do the following:

Remove Percona XtraDB Cluster node from the ProxySQL database
Stop the ProxySQL monitoring daemon for this node
Remove the application user for this cluster
Remove any query rules set up for this cluster

The following example shows how to disable ProxySQL and remove the Percona XtraDB Cluster node:

$ proxysql-admin --config-file=/etc/proxysql-admin.cnf --disable
*ProxySQL* configuration removed!

Additional options¶

The following extra options can be used:

--adduser

Add Percona XtraDB Cluster application user to ProxySQL database.

$ proxysql-admin --config-file=/etc/proxysql-admin.cnf --adduser

Expected output

Adding Percona XtraDB Cluster application user to *ProxySQL* database
Enter Percona XtraDB Cluster application user name: cluster_user
Enter Percona XtraDB Cluster application user password: cluster_passw0Rd
Added Percona XtraDB Cluster application user to *ProxySQL* database!

--syncusers

Sync user accounts currently configured in Percona XtraDB Cluster to ProxySQL database except for users with no password and the admin user.

Warning

This option also deletes users that are not in Percona XtraDB Cluster from ProxySQL database.

--sync-multi-cluster-users

This option works in the same way as --syncusers, but it does not delete ProxySQL users that are not present in the Percona XtraDB Cluster. It is to be used when syncing proxysql instances that manage multiple clusters.

--node-check-interval

This option configures the interval for monitoring via the proxysql_galera_checker script (in milliseconds).

$ proxysql-admin --config-file=/etc/proxysql-admin.cnf \
--node-check-interval=5000 --enable

--mode

Set the read/write mode for Percona XtraDB Cluster nodes in ProxySQL database, based on the hostgroup.

Supported modes are loadbal and singlewrite.

singlewrite is the default mode, it will accept writes only on one single node (based on the info you provide in --write-node). The remaining nodes will accept only read statements.

Servers can be separated by commas, for example:
```
10.0.0.51:3306,10.0.0.52:3306
```
In the previous example, 10.0.0.51:3306 will be in the writer hostgroup if it is ONLINE. If it is OFFLINE, then 10.0.0.52:3306 will go into the writer hostgroup. And if that node also goes down, then one of the remaining nodes will be randomly chosen for the writer hostgroup. The configuration file is deleted when --disable is used.

singlewrite mode setup:

$ sudo grep "MODE" /etc/proxysql-admin.cnf
export MODE="singlewrite"
$ sudo proxysql-admin --config-file=/etc/proxysql-admin.cnf --write-node=127.0.0.1:25000 --enable
*ProxySQL* read/write configuration mode is singlewrite
[..]
*ProxySQL* configuration completed!

To check the configuration you can run:

mysql> SELECT hostgroup_id,hostname,port,status,comment FROM mysql_servers;
+--------------+-----------+-------+--------+---------+
| hostgroup_id | hostname  | port  | status | comment |
+--------------+-----------+-------+--------+---------+
| 11           | 127.0.0.1 | 25400 | ONLINE | READ    |
| 10           | 127.0.0.1 | 25000 | ONLINE | WRITE   |
| 11           | 127.0.0.1 | 25100 | ONLINE | READ    |
| 11           | 127.0.0.1 | 25200 | ONLINE | READ    |
| 11           | 127.0.0.1 | 25300 | ONLINE | READ    |
+--------------+-----------+-------+--------+---------+
5 rows in set (0.00 sec)

The loadbal mode uses a set of evenly weighted read/write nodes.

loadbal mode setup:

$ sudo proxysql-admin --config-file=/etc/proxysql-admin.cnf --mode=loadbal --enable

This script will assist with configuring *ProxySQL* (currently only Percona XtraDB cluster in combination with *ProxySQL* is supported)

*ProxySQL* read/write configuration mode is loadbal
[..]
*ProxySQL* has been successfully configured to use with Percona XtraDB Cluster

You can use the following login credentials to connect your application through *ProxySQL*

mysql --user=proxysql_user --password=***  --host=127.0.0.1 --port=6033 --protocol=tcp

mysql> SELECT hostgroup_id,hostname,port,status,comment FROM mysql_servers;
+--------------+-----------+-------+--------+-----------+
| hostgroup_id | hostname  | port  | status | comment   |
+--------------+-----------+-------+--------+-----------+
| 10           | 127.0.0.1 | 25400 | ONLINE | READWRITE |
| 10           | 127.0.0.1 | 25000 | ONLINE | READWRITE |
| 10           | 127.0.0.1 | 25100 | ONLINE | READWRITE |
| 10           | 127.0.0.1 | 25200 | ONLINE | READWRITE |
| 10           | 127.0.0.1 | 25300 | ONLINE | READWRITE |
+--------------+-----------+-------+--------+-----------+
5 rows in set (0.01 sec)

--quick-demo

This option is used to setup dummy ProxySQL configuration.
```
$ sudo  proxysql-admin  --enable --quick-demo
```

Expected output

You have selected the dry test run mode. WARNING: This will create a test user (with all privileges) in the Percona XtraDB Cluster & *ProxySQL* installations.

You may want to delete this user after you complete your testing!

Would you like to proceed with '--quick-demo' [y/n] ? y

Setting up proxysql test configuration!

Do you want to use the default *ProxySQL* credentials (admin:admin:6032:127.0.0.1) [y/n] ? y
Do you want to use the default Percona XtraDB Cluster credentials (root::3306:127.0.0.1) [y/n] ? n

Enter the Percona XtraDB Cluster username (super user): root
Enter the Percona XtraDB Cluster user password:
Enter the Percona XtraDB Cluster port: 25100
Enter the Percona XtraDB Cluster hostname: localhost


*ProxySQL* read/write configuration mode is singlewrite

Configuring *ProxySQL* monitoring user..

User 'monitor'@'127.%' has been added with USAGE privilege

Configuring the Percona XtraDB Cluster application user to connect through *ProxySQL*

Percona XtraDB Cluster application user 'pxc_test_user'@'127.%' has been added with ALL privileges, this user is created for testing purposes

Adding the Percona XtraDB Cluster server nodes to *ProxySQL*

*ProxySQL* configuration completed!

*ProxySQL* has been successfully configured to use with Percona XtraDB Cluster

You can use the following login credentials to connect your application through *ProxySQL*

mysql --user=pxc_test_user  --host=127.0.0.1 --port=6033 --protocol=tcp

--include-slaves=host_name:port

This option helps to include specified slave node(s) to ProxySQL database. These nodes will go into the reader hostgroup and will only be put into the writer hostgroup if all cluster nodes are down. Slaves must be read only. Can accept comma-delimited list. If this is used, make sure read_only=1 is included into the slave’s my.cnf configuration file.

Note

With loadbal mode slave hosts only accept read/write requests when all cluster nodes are down.

proxysql_status script¶

There is a simple script to dump ProxySQL configuration and statistics:

Usage:

proxysql-status admin admin 127.0.0.1 6032

Contact us

For free technical help, visit the Percona Community Forum.

To report bugs or submit feature requests, open a JIRA ticket.

For paid support and managed or consulting services , contact Percona Sales.

Last update: 2023-03-24