myreplication

Golang MySql binary log replication listener

Programming language: Go

License: Do What The F*ck You Want To Public License

Tags: Database    

README

Go MySql binary log replication listener

Pure Go Implementation of MySQL replication protocol. This allow you to receive event like insert, update, delete with their datas and raw SQL queries. This code has been developed and maintained by Ven at January 2015.

Installation

go get github.com/2tvenom/myreplication

Test

The project is test with:

• Go 1.3.3
• MySQL 5.5, 5.6 and 5.7 (beta)
• Docker 1.4.1 build 5bc2ff8 (functional tests)

It's not tested in real production situation.

Unit tests

go test

Docker tests

Functonal tests with Docker. Test statement based and row based replication. MySql versions 5.5, 5.6, 5.7.

cd tests
sudo ./test.sh

MySQL server settings

In your MySQL server configuration file you need to enable replication:

[mysqld]
server-id        = 1
log_bin          = /var/log/mysql/mysql-bin.log
expire_logs_days = 10
max_binlog_size  = 100M
binlog-format    = row #Row based replication

Example

package main

import (
    "fmt"
    "myreplication"
)

var (
    host     = "localhost"
    port     = 3307
    username = "admin"
    password = "admin"
)

func main() {
    newConnection := myreplication.NewConnection()
    serverId := uint32(2)
    err := newConnection.ConnectAndAuth(host, port, username, password)

    if err != nil {
        panic("Client not connected and not autentificate to master server with error:" + err.Error())
    }
    //Get position and file name
    pos, filename, err := newConnection.GetMasterStatus()

    if err != nil {
        panic("Master status fail: " + err.Error())
    }

    el, err := newConnection.StartBinlogDump(pos, filename, serverId)

    if err != nil {
        panic("Cant start bin log: " + err.Error())
    }
    events := el.GetEventChan()
    go func() {
        for {
            event := <-events

            switch e := event.(type) {
            case *myreplication.QueryEvent:
                //Output query event
                println(e.GetQuery())
            case *myreplication.IntVarEvent:
                //Output last insert_id  if statement based replication
                println(e.GetValue())
            case *myreplication.WriteEvent:
                //Output Write (insert) event
                println("Write", e.GetTable())
                //Rows loop
                for i, row := range e.GetRows() {
                    //Columns loop
                    for j, col := range row {
                        //Output row number, column number, column type and column value
                        println(fmt.Sprintf("%d %d %d %v", i, j, col.GetType(), col.GetValue()))
                    }
                }
            case *myreplication.DeleteEvent:
                //Output delete event
                println("Delete", e.GetTable())
                for i, row := range e.GetRows() {
                    for j, col := range row {
                        println(fmt.Sprintf("%d %d %d %v", i, j, col.GetType(), col.GetValue()))
                    }
                }
            case *myreplication.UpdateEvent:
                //Output update event
                println("Update", e.GetTable())
                //Output old data before update
                for i, row := range e.GetRows() {
                    for j, col := range row {
                        println(fmt.Sprintf("%d %d %d %v", i, j, col.GetType(), col.GetValue()))
                    }
                }
                //Output new
                for i, row := range e.GetNewRows() {
                    for j, col := range row {
                        println(fmt.Sprintf("%d %d %d %v", i, j, col.GetType(), col.GetValue()))
                    }
                }
            default:
            }
        }
    }()
    err = el.Start()
    println(err.Error())
}

Links

• MySql documentation http://dev.mysql.com/doc/internals/en/client-server-protocol.html
• Python implementation. MySql 5.6 checksum compatibility https://github.com/noplay/python-mysql-replication
• Go MySql client. Password encryption method https://github.com/ziutek/mymysql
• Java implementation. Decimal type parsing https://github.com/whitesock/open-replicator
• Ruby implementation. Decimal type parsing https://github.com/jeremycole/mysql_binlog
• Docker files https://github.com/docker-library/mysql

Licence

WTFPL