Wizard

Wizard is database/sql management library for multi instance and sharding in golang. Inspired by MixedGauge

Supported orm list

• xorm

Quick Usage

Register database clusters

import (
_ "github.com/go-sql-driver/mysql""github.com/go-xorm/xorm""github.com/evalphobia/wizard"
)
typeBlogstruct {
ArticleIDstring`xorm:"article_id pk VARCHAR(255) not null"`Contentstring`xorm:"content text"`
}
typeUserstruct {
IDint64`xorm:"id pk BIGINT(20) not null" shard_key:"true"`Namestring`xorm:"name VARCHAR(100) not null"`
}
funcmain() {
wiz=wizard.NewWizard()
/** register normal cluster	*/// create enginesblogMaster, _=xorm.NewEngine("mysql", "root:@tcp(db-master:3306)/blog?charset=utf8")
blogSlave01, _=xorm.NewEngine("mysql", "root:@tcp(db-slave01:3306)/blog?charset=utf8")
blogSlave02, _=xorm.NewEngine("mysql", "root:@tcp(db-slave01:3306)/blog?charset=utf8")
// create cluster with master nodel; CreateCluster(name, master-instance)blogCluster:=wiz.CreateCluster(Blog{}, blogMaster)
blogCluster.RegisterSlave(blogSlave01) // add slavesblogCluster.RegisterSlave(blogSlave02)
/** register shard clusters	*/// shard oneuser01Master, _=xorm.NewEngine("mysql", "root:@/tcp(shard01-master:3306)/users?charset=utf8")
user01Slave01, _=xorm.NewEngine("mysql", "root:@/tcp(shard01-slave01:3306)/users?charset=utf8")
user01Slave02, _=xorm.NewEngine("mysql", "root:@/tcp(shard01-slave02:3306)/users?charset=utf8")
// shard twouser02Master, _=xorm.NewEngine("mysql", "root:@/tcp(shard02-master:3306)/users?charset=utf8")
user02Slave01, _=xorm.NewEngine("mysql", "root:@/tcp(shard02-slave01:3306)/users?charset=utf8")
user02Slave02, _=xorm.NewEngine("mysql", "root:@/tcp(shard02-slave02:3306)/users?charset=utf8")
// create shard clusters; CreateShardCluster(name, slot-size)shardClusters:=wiz.CreateShardCluster(User{}, 1023)
// create single shard set #1shardCluster01:=wizard.NewCluster(user01Master)
shardCluster01.RegisterSlave(user01Slave01)
shardCluster01.RegisterSlave(user01Slave02)
// create single shard set #2shardCluster02:=wizard.NewCluster(user02Master)
shardCluster02.RegisterSlave(user02Slave01)
shardCluster02.RegisterSlave(user02Slave02)
// register shards with slot; RegisterShard(min, max, cluster)shardClusters.RegisterShard(0, 500, shardCluster01)
shardClusters.RegisterShard(501, 1022, shardCluster02)
}

Query on database clusters

import (
"fmt""github.com/evalphobia/wizard/orm/xorm"
)
funcmain() {
orm:=xorm.New(wiz)
blog:=&Blog{ArticleID: "hello-world"}
has, err:=orm.Get(blog, func(s xorm.Session) (bool, error) {
returns.Get(blog)
})
// => SELECT * FROM blog WHERE article_id = "hello-world"; -- execute on blog SLAVEfmt.Println(has)
fmt.Println(blog.Content)
user:=&User{
ID: 1600, // 1600 % 1023 = 577; => shard02Name: "Adam Smith",
}
err=orm.Begin(user) // => BEGIN; -- execute on user02-MASTERiferr!=nil {
panic("Error on transaction beginning")
}
total, err:=orm.Insert(user, func(s xorm.Session) (int64, error) {
returns.Insert(user)
})
// => INSERT INTO users VALUES(1600, "Adam Smith"); -- execute on user02-MASTERfmt.Println(total)
newUser:=&User{ID: 1600}
has, err=orm.GetUsingMaster(newUser, func(s xorm.Session) (bool, error) {
returns.Get(newUser)
})
// => SELECT * FROM users WHERE id = 1600; -- execute on user02-MASTERerr=orm.Commit(user)
// => COMMIT; -- execute on user02-MASTERiferr!=nil {
panic("Error on transaction ending")
}
}

Notes

• Clusters is selected by name, which can be any value like string, struct, pointer.
  • the pointer value automatically converts to the non-pointer value.
• Struct field tag: shard_key:"true" is used as a shard-key
  • shard_key is divided by slot size and the mod value is used for shard mapping
  • string shard_key convert to int64 with CRC64 and divided by slot-size

Other info

• Slide "golang.tokyo #7 Wizard"