我正在使用Web服务的相同电子邮件地址对用户注册进行负载测试，并且同时连接的前10个用户将始终注册。

我正在使用WATCH和MULTI，但这似乎没有任何作用。

我正在调用save（）来保存用户。

this.insert = function(callback) {
    this.preInsert();

    created = new Date();
    updated = new Date();

    // Also with these uncommented it still doesn't work
    // Common.client.watch("u:" + this.username);
    // Common.client.watch("em:" + this.email);

    console.log(ID + " email is locked " + this.email);
    Common.client.multi()
    .set("u:" + this.username, ID)
    .hmset("u:" + ID, 
        {"username": this.username
        ,"password": this.password
        ,"email": this.email
        ,"payment_plan": payment_plan
        ,"created": created.getTime()
        ,"updated": updated.getTime()
        ,"avatar": this.avatar})
    .zadd("u:users", 0, ID)
    .sadd("u:emails", this.email)
    .set("u:"+ ID + ":stats", 0)
    .set("em:" + this.email, ID)
    .exec();

    this.postInsert();

    if (callback != null)
        callback(null, this);
}

this.save = function(callback) {
    // new user
    if (ID == -1) {
        var u = this;

        Common.client.watch("u:" + this.username);
        Common.client.exists("u:" + this.username, function(error, exists) {
            // This username already exists
            if (exists == 1) {
                Common.client.unwatch();
                if (callback != null)
                    callback({code: 100, message: "This username already exists"});
            }
            else {
                Common.client.watch("em:" + u.email);
                Common.client.get("em:" + u.email, function(err, emailExists) {
                    if (emailExists != null) {
                        Common.client.unwatch();
                        if (callback != null)
                            callback({code: 101, message: "This email is already in use"});
                    }
                    else {
                        Common.client.incr("u:nextID", function(error, id) {
                            if (error) callback(error);
                            else {
                                ID = id;
                                u.insert(callback);
                            } 
                        });
                    }
                });
            }
        });
    }
    // existing user
    else {
        var u = this;
        Common.client.get("em:" + this.email, function(err, emailExists) {
            if (emailExists != ID && emailExists) {
                if (callback != null) {
                    callback({code: 101, message: "This email is already in use " + ID + " " + emailExists});
                }
            }
            else {
                u.update(callback);
            }
        });
    }
}

输出几乎总是：

1 email is locked test@test.com
2 email is locked test@test.com
3 email is locked test@test.com
4 email is locked test@test.com
5 email is locked test@test.com
6 email is locked test@test.com
7 email is locked test@test.com
8 email is locked test@test.com
9 email is locked test@test.com
10 email is locked test@test.com

我是在做错什么，还是redis无法处理那么多的并发。这也是Common的定义：

var Common = {
    client: redis.createClient(),
...
};