proxysql

README

ProxySQL

This package implements freno store support for ProxySQL

Logic

Freno will probe servers found in the stats.stats_mysql_connection_pool ProxySQL admin table that have either status:

1. ONLINE - connect, ping and replication checks pass
2. SHUNNED_REPLICATION_LAG - connect and ping checks pass, but replication is lagging

All other statuses are considered unhealthy and therefore are ignored by freno, eg:

1. SHUNNED - proxysql connot connect and/or ping a backend
2. OFFLINE_SOFT - a server that is draining, usually for maintenance, etc
3. OFFLINE_HARD - a server that is completely offline

Requirements

1. The ProxySQL admin port is reachable to Freno
2. The ProxySQL global variable admin-stats_credentials is defined
   • ProxySQLUser in MySQLConfigurationSettings (global) or User in ProxySQLConfigurationSettings (per-cluster) must be equal to admin-stats_credentials
   • ProxySQLPassword in MySQLConfigurationSettings (global) or Password in ProxySQLConfigurationSettings (per-cluster) must be equal to admin-stats_credentials
3. The ProxySQL monitor module is enabled, eg: mysql-monitor_enabled is true
   • The ProxySQL --no-monitor daemon flag cannot be set
4. The max_replication_lag column is defined for backend servers in the mysql_servers admin table
   • This ensures reads do not receive stale data but lagging nodes are still probed

Documentation

Index

• type Client
  • func NewClient(defaultIgnoreServerTTL time.Duration) *Client
  • func (c *Client) CloseDB(addr string)
  • func (c *Client) GetDB(settings config.ProxySQLConfigurationSettings) (*sql.DB, string, error)
  • func (c *Client) GetServers(db *sql.DB, settings config.ProxySQLConfigurationSettings) (servers []*MySQLConnectionPoolServer, err error)
• type MySQLConnectionPoolServer
  • func (ms *MySQLConnectionPoolServer) Address() string

Types

type Client

type Client struct {
	// contains filtered or unexported fields
}

Client is the ProxySQL admin client

func NewClient

func NewClient(defaultIgnoreServerTTL time.Duration) *Client

NewClient returns a new ProxySQL admin client

func (*Client) CloseDB

func (c *Client) CloseDB(addr string)

CloseDB closes a ProxySQL admin connection based on an address string

func (*Client) GetDB

func (c *Client) GetDB(settings config.ProxySQLConfigurationSettings) (*sql.DB, string, error)

GetDB returns a configured ProxySQL admin connection

func (*Client) GetServers

func (c *Client) GetServers(db *sql.DB, settings config.ProxySQLConfigurationSettings) (servers []*MySQLConnectionPoolServer, err error)

GetServers returns a list of MySQLConnectionPoolServers with 'ONLINE' or 'SHUNNED_REPLICATION_LAG' status, based on hostgroup ID

type MySQLConnectionPoolServer

type MySQLConnectionPoolServer struct {
	Host   string
	Port   int32
	Status string
}

MySQLConnectionPoolServer represents a row in the stats_mysql_connection_pool table

func (*MySQLConnectionPoolServer) Address

func (ms *MySQLConnectionPoolServer) Address() string

Address returns a string of the hostname/port of a server