golang实现基于redis和consul的可水平扩展的排行榜服务范例

err := Rds.ZAdd(
    PlayerLvRankKey,
    redis.Z{
        Score:  lvScoreWithTime(playerInfo.Lv, time.Now().Unix()),
        Member: playerInfo.PlayerID,
    },
).Err()
　　其中lvScoreWithTime根据玩家等级及到达的时间计算score用于排名，等级相同的情况下，先到达等级的计算分值大于后达到的。
　　2.存储玩家自身的信息(名字，ID等)，用于在排行榜中显示，毕竟仅仅只有排行的ID是不够的。这里采用hashset，代码如下
// ma的类型为map[string]string
err := Rds.HMSet(fmt.Sprintf("playerInfo:%d", playerID), ma).Err()
服务器端
　　先初始化redis连接
rdsClient := redis.NewClient(&redis.Options{
        Addr:     fmt.Sprintf("%s:%d", "127.0.0.1", 6379),
        Password: "123456",
        DB:       0,
})
playercache.Rds = rdsClient
rankservice.Rds = rdsClient
　　增加初始玩家信息(略)。
　　注册服务器接口，此部分详细说明请参考《go通过反射使用json字符串调用struct的指定方法及返回json结果》http://changjixiong.com/reflect-invoke-method-of-struct-and-get-json-format-result/
reflectinvoke.RegisterMethod(rankservice.DefaultRankService)
　　将服务注册到consul，此部分详细说明请参考《go使用服务发现系统consul》http://changjixiong.com/use-consul-in-go/
go registerServer()
　　在端口9528上开启服务用于结构client请求并返回结果
ln, err := net.Listen("tcp", "0.0.0.0:9528")
if nil != err {
    panic("Error: " + err.Error())
}
for {
    conn, err := ln.Accept()
    // 对Accept()产生的临时错误的处理，可以参考net/http/server.go中的func (srv *Server) Serve(l net.Listener)
    if err != nil {
        panic("Error: " + err.Error())
    }
    go RankServer(conn)
}
　　增加玩家经验及设置玩家的排行榜数据的接口如下
func (rankService *RankService) AddPlayerExp(playerID, exp int) bool {
    player := playercache.GetPlayerInfo(playerID)
    if nil == player {
        return false
    }
    player.Exp += exp
    // 固定经验升级，可以按需要修改
    if player.Exp >= playercache.LvUpExp {
        player.Lv += 1
        player.Exp = player.Exp - playercache.LvUpExp
        rankService.SetPlayerLvRank(player)
    }
    playercache.SetPlayerInfo(player)
    return true
}
func (rankService *RankService) SetPlayerLvRank(playerInfo *playercache.PlayerInfo) bool {
    if nil == playerInfo {
        return false
    }
    err := Rds.ZAdd(
        PlayerLvRankKey,
        redis.Z{
            Score:  lvScoreWithTime(playerInfo.Lv, time.Now().Unix()),
            Member: playerInfo.PlayerID,
        },
    ).Err()
    if nil != err {
        log.Println("RankService: SetPlayerLvRank:", err)
        return false
    }
    return true
}
　　获取指定排行的玩家信息的接口
func (rankService *RankService) GetPlayerByLvRank(start, count int64) []*playercache.PlayerInfo {
    playerInfos := []*playercache.PlayerInfo{}
    ids, err := Rds.ZRevRange(PlayerLvRankKey, start, start+count-1).Result()
    if nil != err {
        log.Println("RankService: GetPlayerByLvRank:", err)
        return playerInfos
    }
    for _, idstr := range ids {
        id, err := strconv.Atoi(idstr)
        if nil != err {
            log.Println("RankService: GetPlayerByLvRank:", err)
        } else {
            playerInfo := playercache.LoadPlayerInfo(id)
            if nil != playerInfos {
                playerInfos = append(playerInfos, playerInfo)
            }
        }
    }
    return playerInfos
}
客户端
　　连接到consul并查到到排行榜服务的地址，连接并发送请求
func main() {
    client, err := consulapi.NewClient(consulapi.DefaultConfig())
    if err != nil {
        log.Fatal("consul client error : ", err)
    }
    for {
        time.Sleep(time.Second * 3)
        var services map[string]*consulapi.AgentService
        var err error
        services, err = client.Agent().Services()
        log.Println("services", strings.Repeat("-", 80))
        for _, service := range services {
            log.Println(service)
        }
        if nil != err {
            log.Println("in consual list Services:", err)
            continue
        }
        if _, found := services["rankNode_1"]; !found {
            log.Println("rankNode_1 not found")
            continue
        }
        log.Println("choose", strings.Repeat("-", 80))
        log.Println("rankNode_1", services["rankNode_1"])
        sendData(services["rankNode_1"])
    }
}