Order
This article mainly studies how to use alibaba’s open source current limiting component Sentinel
maven
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-sentinel</artifactId>
<version>0.2.0.BUILD-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
- Spring-cloud-starter-sentinel will install it locally if it does not exist in maven warehouse.
Configuration
server.port=8080
spring.application.name=sentinel-demo
spring.cloud.sentinel.port=7080
spring.cloud.sentinel.dashboard=localhost:9999
management.endpoints.web.exposure.include=*
- The port of the application specified here is 8080, the communication port with sentinel server is 7080, and the address of sentinel server is localhost:9999
Start dashboard
java -Dserver.port=9999 \
-Dcsp.sentinel.dashboard.server=localhost:9999 \
-Dproject.name=sentinel-dashboard \
-jar sentinel-dashboard.jar
Add current limit rules
Sentinel endpoint to access application:http://localhost: 8080/Actor/Sentinel, returned as follows:
{
"DegradeRules": [],
"SystemRules": [],
"FlowRules": [
{
"resource": "/actuator",
"limitApp": "default",
"grade": 1,
"count": 10,
"strategy": 0,
"refResource": null,
"controlBehavior": 0,
"warmUpPeriodSec": 10,
"maxQueueingTimeMs": 500
}
],
"properties": {
"enabled": true,
"port": "7080",
"dashboard": "localhost:9999",
"filter": {
"order": -2147483648,
"urlPatterns": [
"/*"
]
}
}
}
Current limit verification
wrk -t12 -c1000 -d10s -T30s --latency http://localhost:8080/actuator
Access dashboard
The number of rejections per minute can be seen, and the graphical curve can also be seen through real-time monitoring.
The blue curve is b_qps, i.e. qps requested by blocked
After being fluidised, the interface returns
curl -i http://localhost:8080/actuator
HTTP/1.1 200
Transfer-Encoding: chunked
Date: Sun, 12 Aug 2018 13:41:15 GMT
Blocked by Sentinel (flow limiting)
Summary
The components used here are spring-cloud-alibaba components, similar to spring-cloud-netlfix, which are part of alibaba’s open source components integrated into spring cloud. It is very convenient to integrate sentinel now.