8应用7一毛不拔漏斗限流天下无鱼

应⽤7#coding:utf8importtimeclass init(self,capacity,leaking_rate):self.capacity=capacity#漏⽃容量self.leaking_rateleaking_rate漏嘴流

self.left_quotacapacityself.leaking_tstime.time()defmake_space(self):now_ts=time.time()delta_tsnow_tsself.leaking_tsdelta_quota=delta_ts*self.leaking_rate#⼜可以腾出不少空间了ifdelta_quota1:self.left_quotadelta_quotaself.leaking_tsnow_tsifself.left_quotaself.capacity:self.left_quota=defwatering(self,quota):ifself.left_quotaquota:self.left_quota-=quotareturnTruereturnfunnelscapacityleaking_rate漏嘴流⽔速率quota/sdefis_action_allowed(user_id,action_key,capacity,key='%s:%s'%(user_id,action_key)funnel=funnels.get(key)ifnotfunnel=Funnel(capacity,leaking_rate)funnels[key]=funnelreturnforiinprintis_action_allowed('laoqian','reply',15,0.5)JavapublicpublicclassFunnelRateLimiterstaticclass{intcapacity;floatleakingRate;intleftQuota;longleakingTs;publicFunnel(intcapacity,floatleakingRate){this.capacity=capacity;this.leakingRate=leakingRate;this.leftQuota=capacity;this.leakingTs=}voidmakeSpace()longnowTs=System.currentTimeMillis();longdeltaTs=nowTs-leakingTs;intdeltaQuota=(int)(deltaTs*if(deltaQuota0this.leftQuota=capacity;this.leakingTs=nowTs;}if(deltaQuota1是}this.leftQuota+=deltaQuota;this.leakingTs=nowTs;if(this.leftQuota>this.capacity)this.leftQuota=}}booleanwatering(int{if(this.leftQuota>={this.leftQuota-=quota;returntrue;}return}}privateMap<String,Funnel>funnels=newpublicbooleanisActionAllowed(StringuserId,StringactionKey,intcapacity,floatleakingRate){Stringkey=String.format("%s:%s",userId,Funnelfunnel=funnels.get(key);if(funnel==null){funnel=newFunnel(capacity,leakingRate);funnels.put(key,funnel);}returnfunnel.watering(1需要1个}}Funnel对象的make_space决于过去了多久以及流⽔的速率。Funnel对象占据的空间⼤⼩不再Redis的基我们观察Funnel对象的⼏个字段，我们发现可以将Funnel对象的内容按字段存储到⼀个hash结构中，灌⽔的时候将hash结构的字段取出来进⾏逻辑运算后，再将新值回填到hash结构中就完成了⼀但是有个问题，我们⽆法保证整个过程的原⼦性。从hash结构中取值，然后在内存⾥运算，再回填到hash结构，这三个过程⽆法原⼦们该如何解决这个问题呢？Redis-Cell救星来了！Redis-Redis4.0提供了⼀个限流Redis模块，它叫redis-cell。该模块也>cl.throttle1▲▲▲▲▲||||└─────1quota可选参数，默认值也是 |└──┴───────30operations/60seconds这是漏⽔速率 └─────────────capacity上⾯这个指令的意思是允许「⽤户⽼钱回复⾏为」的频率为每60s最多30次(漏⽔速率)，漏⽃的初始容量为15，也就是说⼀开始可以连续回复15个帖⼦，然后才开始受漏⽔速率的影响。我们看到这个指令中漏⽔速率变成了2个参数，替代了之前的单个浮点数。⽤>>cl.throttlelaoqian:reply1530(integer)(integer)(integer)4)(integer)-0表示允许，1漏⽃容量漏⽃剩余空间5(integer 组的第四个值进⾏sleep即可，如果不想阻塞线程，也可以异步定漏⽃限流模块除了应⽤于UGC1.《Redis-Cell作者ItamarHaberRedis-Cell作者ItamarHa