README

Sentinel: The Sentinel of Your Microservices










 Introduction

As distributed systems become increasingly popular, the reliability between services is becoming more important than ever before.
Sentinel takes "flow" as breakthrough point, and works on multiple fields including flow control, traffic shaping,
concurrency limiting, circuit breaking and system adaptive overload protection,
to guarantee reliability and resilience for microservices.

Sentinel has the following features:

- Rich applicable scenarios: Sentinel has been wildly used in Alibaba, and has covered almost all the core-scenarios in Double-11 (11.11) Shopping Festivals in the past 10 years, such as “Second Kill” which needs to limit burst flow traffic to meet the system capacity, message peak clipping and valley fills, circuit breaking for unreliable downstream services, cluster flow control, etc.
- Real-time monitoring: Sentinel also provides real-time monitoring ability. You can see the runtime information of a single machine in real-time, and the aggregated runtime info of a cluster with less than 500 nodes.
- Widespread open-source ecosystem: Sentinel provides out-of-box integrations with commonly-used frameworks and libraries such as Spring Cloud, gRPC, Apache Dubbo and Quarkus. You can easily use Sentinel by simply add the adapter dependency to your services.
- Polyglot support: Sentinel has provided native support for Java, Go, C++ and Rust.
- Various SPI extensions: Sentinel provides easy-to-use SPI extension interfaces that allow you to quickly customize your logic, for example, custom rule management, adapting data sources, and so on.

Features overview:

!features-of-sentinel

The community is also working on the specification of traffic governance and fault-tolerance.
Please refer to OpenSergo for details.

 Documentation

See the Sentinel Website for the official website of Sentinel.

See the 中文文档 for document in Chinese.

See the Wiki for full documentation, examples, blog posts, operational details and other information.

Sentinel provides integration modules for various open-source frameworks
(e.g. Spring Cloud, Apache Dubbo, gRPC, Quarkus, Spring WebFlux, Reactor) and service mesh.
You can refer to the document for more information.

If you are using Sentinel, please leave a comment here to tell us your scenario to make Sentinel better.
It's also encouraged to add the link of your blog post, tutorial, demo or customized components to Awesome Sentinel.

 Ecosystem Landscape

!ecosystem-landscape

 Quick Start

Below is a simple demo that guides new users to use Sentinel in just 3 steps. It also shows how to monitor this demo using the dashboard.

 1. Add Dependency

Note: Sentinel requires JDK 1.8 or later.

If you're using Maven, just add the following dependency in pom.xml.

xml


    com.alibaba.csp
    sentinel-core
    1.8.10



If not, you can download JAR in Maven Center Repository.

 2. Define Resource

Wrap your code snippet via Sentinel API: SphU.e