alibaba/Sentinel

Redis-based token client implementation of cluster flow control

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#1,188 opened on Dec 5, 2019

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 (4 comments) (0 reactions) (0 assignees)Java (23,109 stars) (8,150 forks)batch import
area/cluster-flowgood first issue

Description

TokenServer为什么不基于Redis时间窗口来实现呢？或者Redis本身就是一个TokenServer呀！ 以“应用名_资源名_规则ID_参数值”作为redis的Key，时间窗口长度（durationInSec）为ttl，创建一条redis记录，创建记录通过 set key value ex ttl nx 指令，确保时间窗口内有且仅有一条有效记录。然后，通过incrBy key count指令进行分布式累积，当累积值超过阀值时，触发限流。 此外，还可以利用redis的分布式和抗压的特点，提长TokenServer的性能。 -- For English user why TokenServer is not based on Redis? or Redis itselt is a good TokenServer! create a redis key like "namespace_resource_flowId_param", ttl=durationInSec, use cmd "set key value ex ttl nx" to make sure in timeWindow only create on record. then use cmd "incrBy key count" for accumulation. if count > threshold then fired block Event.

Contributor guide

Tech stack
javaredis
Domain
backendcloudperformance
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Redis commandsSentinel architectureJavaDistributed locking
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
Investigate existing Redis usage in Sentinel (e.g., in sentinel redis module). Review the cluster flow control architecture and token server interface. Propose a design in the issue including key naming, TTL, and concurrency handling. Test with a simple benchmark to compare performance.