# SpringCloud **Repository Path**: yukewei/SpringCloud ## Basic Information - **Project Name**: SpringCloud - **Description**: SpringCloud的项目，主要是以《重新定义SpringCloud实战》这本书为路线进行学习。 - **Primary Language**: Java - **License**: Not specified - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 1 - **Created**: 2023-05-25 - **Last Updated**: 2023-05-25 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # springcloud 这是一个学习springcloud的工程，主要按照《重新定义SpringCloud实战》这本书为主要导线。 ## Eureka Server的Rest API ### 概念 Eureka Server允许非JAVA语言介入， 所以提供了Rest HTTP来让其他语言介入到服务的注册和发现中。 ### 列表 > 懒得码字了， 转载自 https://www.jianshu.com/p/c24e622f3f45 eureka信息查看 get: {ip:port}/eureka/status 注册到eureka的服务信息查看 get: {ip:port}/eureka/apps 注册到eureka的具体的服务查看 get: {ip:port}/eureka/apps/{appname}/{id} 对应eureka源码的：InstanceResource.getInstanceInfo 服务续约 put：{ip:port}/eureka/apps/{appname}/{id}?lastDirtyTimestamp={}&status=up 对应eureka源码的：InstanceResource.renewLease 更改服务状态 put：{ip:port}/eureka/apps/{appname}/{id}/status?lastDirtyTimestamp={}&value={UP/DOWN} 对应eureka源码的：InstanceResource.statusUpdate 删除状态更新 delete：{ip:port}/eureka/apps/{appname}/{id}/status?lastDirtyTimestamp={}&value={UP/DOWN} 对应eureka源码的：InstanceResource.deleteStatusUpdate 删除服务 delete: {ip:port}/eureka/apps/{appname}/{id} 对应eureka源码的：InstanceResource.cancelLease ### JSON文件 { "info": { "_postman_id": "2fbb0980-9df7-4a96-963c-309644abfe6d", "name": "Spring Cloud", "schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json" }, "item": [ { "name": "RestApi", "item": [ { "name": "查看所有服务", "request": { "method": "GET", "header": [], "url": { "raw": "http://localhost:1001/eureka/apps", "protocol": "http", "host": [ "localhost" ], "port": "1001", "path": [ "eureka", "apps" ] } }, "response": [] }, { "name": "向注册中心注册实例", "request": { "method": "POST", "header": [ { "key": "Content-Type", "name": "Content-Type", "type": "text", "value": "application/xml" } ], "body": { "mode": "raw", "raw": "\n\tdemo-order2:11101\n 127.0.0.1\n\tDEMO-ORDER2\n 127.0.0.1\n\tUP\n\tUNKNOWN\n\t11101\n\t443\n\t1\n\t\n\t MyOwn\n\t\n\t\n\tdemo-order2\n\tdemo-order2\n\tfalse\n\t1540186708769\n\t1540186708747\n" }, "url": { "raw": "http://localhost:1001/eureka/apps/demo-order2", "protocol": "http", "host": [ "localhost" ], "port": "1001", "path": [ "eureka", "apps", "demo-order2" ] } }, "response": [] }, { "name": "删除实例", "request": { "method": "DELETE", "header": [ { "key": "Content-Type", "name": "Content-Type", "type": "text", "value": "application/xml" } ], "body": { "mode": "raw", "raw": "" }, "url": { "raw": "http://localhost:1001/eureka/apps/EUREKA-CLIENT/windows10.microdone.cn:eureka-client:8081", "protocol": "http", "host": [ "localhost" ], "port": "1001", "path": [ "eureka", "apps", "EUREKA-CLIENT", "windows10.microdone.cn:eureka-client:8081" ] } }, "response": [] }, { "name": "暂停/下线应用实例", "request": { "method": "PUT", "header": [], "url": { "raw": "http://localhost:1001/eureka/apps/EUREKA-CLIENT/windows10.microdone.cn:eureka-client:8081/status?value=OUT_OF_SERVICE", "protocol": "http", "host": [ "localhost" ], "port": "1001", "path": [ "eureka", "apps", "EUREKA-CLIENT", "windows10.microdone.cn:eureka-client:8081", "status" ], "query": [ { "key": "value", "value": "OUT_OF_SERVICE" } ] } }, "response": [] }, { "name": "恢复应用实例", "request": { "method": "DELETE", "header": [], "url": { "raw": "http://localhost:1001/eureka/apps/EUREKA-CLIENT/windows10.microdone.cn:eureka-client:8081/status?value=UP", "protocol": "http", "host": [ "localhost" ], "port": "1001", "path": [ "eureka", "apps", "EUREKA-CLIENT", "windows10.microdone.cn:eureka-client:8081", "status" ], "query": [ { "key": "value", "value": "UP" } ] } }, "response": [] }, { "name": "应用实例发送心跳", "request": { "method": "PUT", "header": [], "url": { "raw": "http://localhost:1001/eureka/apps/EUREKA-CLIENT/windows10.microdone.cn:eureka-client:8081", "protocol": "http", "host": [ "localhost" ], "port": "1001", "path": [ "eureka", "apps", "EUREKA-CLIENT", "windows10.microdone.cn:eureka-client:8081" ] } }, "response": [] }, { "name": "修改元数据", "request": { "method": "PUT", "header": [], "url": { "raw": "http://localhost:1001/eureka/apps/EUREKA-CLIENT/windows10.microdone.cn:eureka-client:8081/metadata?profile=canary", "protocol": "http", "host": [ "localhost" ], "port": "1001", "path": [ "eureka", "apps", "EUREKA-CLIENT", "windows10.microdone.cn:eureka-client:8081", "metadata" ], "query": [ { "key": "profile", "value": "canary" } ] } }, "response": [] } ] } ] } ## Eureka的实例状态 在InstanceStatus这个枚举类中定义的。实例共有五种状态。 ``` UP, // Ready to receive traffic DOWN, // Do not send traffic- healthcheck callback failed STARTING, // Just about starting- initializations to be done - do not // send traffic OUT_OF_SERVICE, // Intentionally shutdown for traffic UNKNOWN; ``` ## 服务的核心操作 对于服务实例来说，主要有如下几个操作。 1. 服务注册（register） 2. 服务下线（cancel） 3. 服务租约（renew） 4. 服务剔除（evict） com.netflix.eureka.lease.LeaseManager，这个接口定义了这几项操作。 com.netflix.discovery.shared.LookupService ，这个接口定义了Client端从注册中心获取服务列表的方法。 ## Eureka的设计理念 ### AP优于CP 什么是分布式系统领域的CAP理论。下面这篇文章写的非常好，我给大家贴出来。 https://blog.csdn.net/yeyazhishang/article/details/80758354 总结来说就是，Eureka的设计理念就是及时响应优于数据一致性。 ### Peer 2 Peer 一版来说，分布式系统的数据在多个副本之间的复制方式，可分为主从复制和对等复制。 ### 主从复制 主从复制也就是广为人知的Master-Slave模式，即有一个主副本、其他的副本为从副本。所有的对数据的写操作都提交到主副本，最后再由主副本更新到其他的从副本。 对于主从复制来讲，写的压力都在主副本上，它是整个系统的瓶颈，但是从副本可以帮主副本分担读请求。 ### 对等复制 即Peer 2 Peer模式，副本之间部分主从，任何副本都可以接受写操作，然后每个副本之间进行数据更新。 对于对等复制来说，由于任何副本都可以接收写操作，不存在写操作的压力瓶颈。但是由于每个副本之间都可以进行写操作处理，各个副本之间的数据同步及冲突处理是一个比较棘手的问题。 Eureka采用的就是这种复制方式。 ### Zone和Region设计 ![Region和Zone的原理图](https://img-blog.csdnimg.cn/20190812000333239.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTI5MzYx,size_16,color_FFFFFF,t_70) 就是服务的消费者会优先去找同一个Zone的服务的提供者。当发现提供不了的时候才会去找另外Zone的的服务提供者。