polardbx-connector-go

This is a high-availability Golang driver for PolarDB-X. The features implemented so far are as follows:

• Automatically reconnects to the new leader node after switching
• Supports read-write separation
• Supports CoreDNS
• Built-in polardbx driver keyword
• Supports transparent switching
• Supports COM_PING for HA checks
• Supports Load Balancing (random or leastConn)

A simple example using polardbx as drivername:

import (
	_ "github.com/polardb/polardbx-connector-go"
)
db, err := sql.Open("polardbx", "user:password@tcp(ip:port)/dbname")
if err != nil {
    panic(err)
}

db.SetConnMaxLifetime(time.Minute * 3)
db.SetMaxOpenConns(10)
db.SetMaxIdleConns(10)

Installation

go get github.com/polardb/polardbx-connector-go

New Parameters

Standard Edition (Dn):

Parameter Name	Type	Description
clusterId	int64	Cluster identifier. Optional. Automatically obtained on first connection.
connectTimeout	int32	Timeout for acquiring an available DN node, default 3000ms.
haCheckConnectTimeoutMillis	int32	HA connection check timeout, default 3000ms.
haCheckSocketTimeoutMillis	int32	HA query check timeout, default 3000ms.
haCheckIntervalMillis	int32	HA check interval, default 5000ms.
checkLeaderTransferringIntervalMillis	int32	Leader transfer detection interval, default 100ms.
leaderTransferringWaitTimeoutMillis	int32	Maximum wait time for leader transfer, default 5000ms.
ignoreVip	bool	Whether to ignore VIP address, default true.
recordJdbcUrl	bool	Whether to record DSN, default false.
slaveRead	bool	Whether to use follower read, default false.
slaveWeightThreshold	int32	Follower ELECTION_WEIGHT must be greater than this value to connect, default 1.
applyDelayThreshold	int32	Follower APPLY_DELAY_SECONDS must be <= this value to connect, unit: seconds, default 3.
directMode	bool	Whether to skip HA management, default false.
loadBalanceAlgorithm	string	Load balancing algorithm: random or least_connection.
enableLog	bool	Whether to print driver logs, default true.

example:

db, err := sql.Open("polardbx", "user:password@tcp(ip:port)/dbname?slaveRead=false&slaveWeightThreshold=1&applyDelayThreshold=3)

Enterprise Edition (CN):

Parameter Name	Type	Description
connectTimeout	int32	Timeout for acquiring an available CN node.
haCheckIntervalMillis	int32	HA check interval, default 5000ms.
zoneName	string	Zone name (AZ name), default empty (random selection). Example: AZ0, AZ1.
minZoneNodes	int32	Minimum number of nodes in the zone (greater than), default 0.
backupZoneName	string	Backup zone name used when minZoneNodes is not satisfied.
slaveRead	bool	Whether to use R instance, default false.
instanceName	string	CN instance name, default empty.
mppRole	string	Default W for primary, R for secondary. Can also be set to CR.
enableFollowerRead	int32	0: Use primary; 1: Use secondary for normal read; 2: Secondary for consistent read; -1: No operation (default).
loadBalanceAlgorithm	string	Load balancing algorithm: random or least_connection.
enableLog	bool	Whether to print driver logs, default false.

example:

db, err := sql.Open("polardbx", "user:password@tcp(ip:port)/dbname?slaveRead=true&loadBalanceAlgorithm=random")

Development

Download the Repository

git clone http://github.com/polardb/polardbx-connector-go.git

Install Dependencies

cd polardbx-connector-go
go mod tidy

Build and Test

go test -v -args -dnAddr="ip1:port1, ip2:port2" -dnUser="user1" -dnPasswd="passwd1" -cnAddr="ip3:port3, ip4:port4" -cnUser="user2" -cnPasswd="passwd2" -zoneName="name1" -backupZoneName="name2" -instanceName="name3"