Percona Module

Puppet class to manage a percona cluster along with HAproxy load balancers.

Largely based on https://github.com/Jimdo/puppet-galera

Installs and configures a percona node and associated MySQL/Percona service. By default, this class configures a new cluster consisting of a single node. Subsequent nodes can be joined to the cluster by setting the $joiner parameter to true and nominating a donor via the $donor_ip parameter.

Requirements

• camptocamp/puppet-augeas (For Ubuntu 16.04, >= 1.4.3 is required due to changes in ruby package naming)
• puppetlabs/apt
• puppetlabs/stdlib
• To use the dynamically generated haproxy configs on the client, a working PuppetDB with storeconfigs enabled, in order to use exported resources. This is optional, but highly recommended for production clusters.

Usage

Assign class percona::node via your favourite ENC or simply add a node entry. It's best to start with one node intially, then add the others once the initial node is up and running.

Create a new cluster from scratch

node percona-node1 {
   class { 'percona::node':   
          cluster_name => 'cluster',
   }
 }

!! IMPORTANT !!: In order to avoid the cluster becoming partitioned, the initial node must be redefined as a joiner with a donor IP (not it's own address) once the cluster has been fully created:

 node percona-node1 {
   class { 'percona::node':   
          cluster_name => 'cluster',
          joiner       => true,
          donor_ip     => 'ip.of.donor',
   }
 }

Load balancing/failover

Servers

This node definition will add the node to a HAproxy listener group that's declared on the clients (see Clients section below).

node percona-node1 {
  class { 'percona::haproxy':   
         haproxy_listener => 'loadbalanced_mysql',
  }
}

By default, this class deploys an active-active haproxy load balancer. If you want an active-backup (failover) load balancer, define as follows:

node percona-node1 {
  class { 'percona::haproxy':   
         haproxy_listener => 'loadbalanced_mysql',
         haproxy_failover => true,
         haproxy_primary  => true,
  }
}

Note: Only one node can be haproxy_primary in this configuration. Define the backup nodes without the haproxy_primary statement.

Load balancer(s)

Define a HAproxy load balancer consisting of the servers defined above.

haproxy::listen { $haproxy_listener:
  ipaddress  => '127.0.0.1',
  ports      => '3306',
  options    => {
   'option'  => [
     'tcpka',
     'httpchk',
      'tcplog',
   ],
   'balance' => 'leastconn',
  },
}

Parameters

percona::node

####cluster_name

Type: String. Default: 'my_cluster'. Name of the cluster to create or join.

####joiner

Type: Bool. Default: 'false'. Is the node joining an existing cluster?

####donor_ip

Type: String. Default: '0.0.0.0'. IP of pre-existing node to perform an initial state transfer from when joining a cluster.

####sst_method

Type: String. Default: 'xtrabackup-v2'. SST (state transfer method) to use when joining a cluster. Other possibilities are 'xtrabackup', 'rsync' and 'mysqldump'. See percona docs for further info.

####sst_user

Type: String. Default: 'wsrep_sst'. MySQL user that performs the SST. Only used for the 'mysqldump' SST method.

####sst_password

Type: String. Default: 'password'. Password for SST MySQL user.

####root_password

Type: String. Default: 'password'. Password for the MySQL root user.

####maint_password

Type: String. Default: 'maint'. Password for the debian_sys_maint MySQL user.

####old_root_password

Type: String. Default: ''.

####enabled

Type: Bool. Default: true. Enable or disable the MySQL/Percona service.

####package_name

Type: String. Default: 'percona-xtradb-cluster-server-5.6'. Name of the percona package to install.

####repo_location Type: String. Default: 'http://repo.percona.com/apt'. Location of the apt repo to use.

####percona_notify_from Type: String. Default: 'percona-noreply@example.com˙. From address for percona notifications.

####percona_notify_to Type: String. Default: 'root@localhost'. Where to send percona notifications.

####wsrep_node_address Type: String. Default: Undefined. Source IP address to use for xtrabackup etc.

####ssl_replication Type: Bool. Default: False. Enable wsrep encryption with SSL. You must set the ssl_replication_cert and ssl_replication_key variables if this is enabled. This must be same across the cluster.

####ssl_replication_cert Type: String. Default: Undefined. SSL certificate to use for replication. This must be same across the cluster.

####ssl_replication_key Type: String. Default: Undefined. SSL key to use for replication. This must be same across the cluster.

MySQL tuning

It is also possible to set a number of parameters via the $tune_ variables and the $tune_other_options array. Consult the MySQL documentation for these. As these values are very machine-dependent they should be set with hiera or something similar:

database-server-with-loads-of-ram.yaml:

 ---
 percona::node:tune_innodb_buffer_pool_size: '40G'
 percona::node:tune_innodb_flush_method: 'O_DIRECT'

These variables are set to the defaults recommended by the MySQL documentation.