go-mysql

README

go-mysql

A pure go library to handle MySQL network protocol and replication.

Replication

Replication package handles MySQL replication protocol like python-mysql-replication.

You can use it as a MySQL slave to sync binlog from master then do something, like updating cache, etc...

Example

import (
    "github.com/siddontang/go-mysql/replication"
    "os"
)
// Create a binlog syncer with a unique server id, the server id must be different from other MySQL's. 
syncer := replication.NewBinlogSyncer(100)

// Register slave, the MySQL master is at 127.0.0.1:3306, with user root and an empty password
syncer.RegisterSlave("127.0.0.1", 3306, "root", "")

// Start sync with sepcified binlog file and position
streamer, _ := syncer.StartSync(binlogFile, binlogPos)

for {
    ev, _ := streamer.GetEvent()
    // Dump event
    ev.Dump(os.Stdout)
}

The output looks:

=== RotateEvent ===
Date: 1970-01-01 08:00:00
Log position: 0
Event size: 43
Position: 4
Next log name: mysql.000002

=== FormatDescriptionEvent ===
Date: 2014-12-18 16:36:09
Log position: 120
Event size: 116
Version: 4
Server version: 5.6.19-log
Create date: 2014-12-18 16:36:09

=== QueryEvent ===
Date: 2014-12-18 16:38:24
Log position: 259
Event size: 139
Salve proxy ID: 1
Execution time: 0
Error code: 0
Schema: test
Query: DROP TABLE IF EXISTS `test_replication` /* generated by server */

Client

Client package supports a simple MySQL connection driver which you can use it to communicate with MySQL server.

Example

import (
    "github.com/siddontang/go-mysql/client"
)

// Connect MySQL at 127.0.0.1:3306, with user root, an empty passowrd and database test
conn, _ := client.Connect("127.0.0.1:3306", "root", "", "test")

conn.Ping()

// Insert
r, _ := conn.Execute(`insert into table (id, name) values (1, "abc")`)

// Get last insert id
println(r.InsertId)

// Select
r, _ := conn.Execute(`select id, name from table where id = 1`)

// Handle resultset
v, _ := r.GetInt(0, 0)
v, _ = r.GetIntByName(0, "id") 

Server

Server package supplies a framework to implement a simple MySQL server which can handle the packets from the MySQL client. You can use it to build your own MySQL proxy.

Example

import (
    "github.com/siddontang/go-mysql/server"
    "net"
)

l, _ := net.Listen("127.0.0.1:4000")

c, _ := l.Accept()

// Create a connection with user root and an empty passowrd
// We only an empty handler to handle command too
conn, _ := server.NewConn(c, "root", "", server.EmptyHandler{})

for {
    conn.HandleCommand()
}

Another shell

mysql -h127.0.0.1 -P4000 -uroot -p 
//Becuase empty handler does nothing, so here the MySQL client can only connect the proxy server. :-) 

Failover

Failover supports to promote a new master and let other slaves replicate from it automatically when the old master was down.

Failover only support MySQL >= 5.6.9 with GTID mode, if you use lower version, e.g, MySQL 5.0 - 5.5, please use MHA or orchestrator.

Failover may try to support MariaDB with GTID mode later.

Why only GTID? Supporting failover with no GTID mode is very hard, because slave can not find the proper binlog filename and position with the new master. Although there are many companies use MySQL 5.0 - 5.5, I think upgrade MySQL to 5.6 or higher is easy.

Feedback

go-mysql is still in development, your feedback is very welcome.

Gmail: siddontang@gmail.com