Communication on differ-structure servicecenters

ServiceCenter and Eureka

Situation description：

EurekaServer： The Service-center of Eureka
AccountServer：The account server of register to Eureka
Servicecomb-ServiceCenter：Servicecomb-ServiceCenter
HelloServer：The server of register to Servicecomb-ServiceCenter，that dependent on account server

Instances cannot be discovered and accessed by each other between different service centers, in a traditional environment. This will be easy to implement when we use Syner. As shown below:

Operating environment

2 linux machines: （Host IP is like this：10.0.0.10 和 10.0.0.11）
JDK 1.8
Maven 3.x
Go 1.11.4

Before starting：

Install ServiceCenter Release（>=1.3.0）

$ project_dir=`pwd`
$ tar -zxvf  apache-servicecomb-service-center-1.3.0-linux-amd64.tar.gz

Download the sample

git clone https://github.com/apache/servicecomb-service-center.git
cd ${project_dir}/servicecomb-service-center/syncer

Step 1: Launch the Eureka environment and services

One of the machines： 10.0.0.10

1. Compile EurekaServer and AccountServer

$ cd samples/multi-servicecenters/eureka
$ mvn clean install

2. Run EurekaServer：

Modify the startup configuration File path：${project_dir}/servicecomb-service-center/syncer/samples/multi-servicecenters/eureka/eureka-server/src/main/resources/application.yaml

spring:
application:
  name: eureka-server
server:
port : 8761
#  servlet:
#    context-path: /eureka
eureka:
instance:
  hostname : 10.0.0.10
client:
  registerWithEureka : false
  fetchRegistry : false
  serviceUrl:
    defaultZone : http://${eureka.instance.hostname}:${server.port}/eureka/
management:
endpoints:
  web:
    exposure:
      include: "*"

Run server

$ cd ${project_dir}/servicecomb-service-center/syncer/samples/multi-servicecenters/eureka/eureka-server/
$ nohup mvn spring-boot:run & >> eureka-server.log 2>&1 &

Open http://10.0.0.10:8761 in the browser, this is successful if the following page appears.

3. Run AccountServer

Modify the startup configuration
File path：${project_dir}/servicecomb-service-center/syncer/samples/multi-servicecenters/eureka/account-server/src/main/resources/application.yaml

spring:
application:
  name: account-server
server:
port: 8090
eureka:
instance:
  hostname: 10.0.0.10
client:
  service-url:
    defaultZone: http://${eureka.instance.hostname}:8761/eureka/
management:
endpoints:
  web:
    exposure:
      include: "*"

Start AccountServer

$ cd ${project_dir}/servicecomb-service-center/syncer/samples/multi-servicecenters/eureka/account-server
$ mvn spring-boot:run
#This is successful if the result like this，
2019-09-19 17:20:35.534  INFO 20890 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8090 (http) with context path ''
2019-09-19 17:20:35.548  INFO 20890 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 8090
2019-09-19 17:20:35.551  INFO 20890 --- [           main] o.a.s.s.account.AccountApplication       : Started AccountApplication in 3.92 seconds (JVM running for 6.754)
2019-09-19 17:20:35.617  INFO 20890 --- [nfoReplicator-0] com.netflix.discovery.DiscoveryClient    : DiscoveryClient_ACCOUNT-SERVER/10.0.0.10:account-server:8090 - registration status: 204

Reopen http://10.0.0.10:8761, you can see that AccountServer has been registered successfully.

4. Run Syncer of eureka

$ cd ${project_dir}/apache-servicecomb-service-center-1.3.0-linux-amd64/
$ ./syncer daemon --sc-addr http://10.0.0.10:8761/eureka --bind-addr 10.0.0.10:30190 --rpc-addr 10.0.0.10:30191 --sc-plugin=eureka  --node eureka
#This is successful if the result like this，
2019-09-19T17:28:28.809+0800	INFO	etcd/agent.go:55	start etcd success
2019-09-19T17:28:28.809+0800	INFO	grpc/server.go:94	start grpc success
2019-09-19T17:28:28.809+0800	DEBUG	server/handler.go:39	is leader: true
2019-09-19T17:28:28.809+0800	DEBUG	server/handler.go:43	Handle Tick

Step 2: Start the Servicecenter environment and services

Another machine： 10.0.0.11

1. Compile HelloServer

$ cd ${project_dir}/servicecomb-service-center/syncer/samples/multi-servicecenters/servicecenter/hello-server/
$ GO111MODULE=on go build

2. Run Servicecenter

Modify the startup configuration：
File path：${project_dir}/apache-servicecomb-service-center-1.3.0-linux-amd64/conf/app.conf

frontend_host_ip = 10.0.0.11
frontend_host_port = 30103
#sever options
#if you want to listen at ipv6 address, then set the httpaddr value like:
#httpaddr = 2400:A480:AAAA:200::159        (global scope)
#httpaddr = fe80::f816:3eff:fe17:c38b%eth0 (link-local scope)
httpaddr = 10.0.0.11
httpport = 30100
#...以下省略...

Run ServiceCenter and Frontend

$ cd ${project_dir}/apache-servicecomb-service-center-1.3.0-linux-amd64
$ ./start-service-center.sh
$ ./start-frontend.sh

Open http://10.0.0.11:30103 in the browser, this is successful if the following page appears.

3. Run HelloServer

Modify the startup configuration
File path：${project_dir}/servicecomb-service-center/syncer/samples/multi-servicecenters/servicecenter/hello-server/conf/microservice.yaml

service: # Micro service configuration
appId: eureka # The appID is "eureka", if the instance synced from eureka.
name: hello-server
version: 0.0.1
instance: # Instance information
  protocol: rest
  listenAddress: 10.0.0.11:8091 #The listening address of the instance
provider: # Provider information
appId: eureka
name: account-server
version: 0.0.1
registry:
address: http://10.0.0.11:30100

Start HelloServer

$ cd ${project_dir}/servicecomb-service-center/syncer/samples/multi-servicecenters/servicecenter/hello-server
$ ./hello-server
2019-09-19T18:37:50.645+0800	DEBUG	servicecenter/servicecenter.go:163	send heartbeat success
2019-09-19T18:37:50.645+0800	WARN	servicecenter/servicecenter.go:85	discovery provider failed, appID = eureka, name = account-server, version = 0.0.1
2019-09-19T18:37:50.645+0800	INFO	servicecenter/servicecenter.go:87	waiting for retry

Reopen http://10.0.0.11:30103, you can see that HelloServer has been registered successfully.

But, the instance of AccountServer belonging to the EurekaServer cannot be found, the HelloServer is in the retry state.
(Warning: We must complete the operation within 3 retry times (90 seconds))

4.Run Syncer of service-center

$ cd ${project_dir}/apache-servicecomb-service-center-1.3.0-linux-amd64/
$ ./syncer daemon --sc-addr http://10.0.0.11:30100 --bind-addr 10.0.0.11:30190 --rpc-addr 10.0.0.11:30191 --sc-plugin=servicecenter --join-addr 10.0.0.10:30190 --node servicecenter
#This is successful if the result like this，
2019-09-19T18:44:35.536+0800	DEBUG	server/handler.go:62	is leader: true
2019-09-19T18:44:35.536+0800	DEBUG	server/handler.go:79	Receive serf user event
2019-09-19T18:44:35.536+0800	DEBUG	serf/agent.go:130	member = servicecenter, groupName = 0204d59328090c2f4449a088d4e0f1d8
2019-09-19T18:44:35.536+0800	DEBUG	serf/agent.go:130	member = eureka, groupName = 34f53a9520a11c01f02f58f733e856b3
2019-09-19T18:44:35.536+0800	DEBUG	server/handler.go:97	Going to pull data from eureka 10.0.0.10:30191
2019-09-19T18:44:35.536+0800	INFO	grpc/client.go:76	Create new grpc connection to 10.0.0.10:30191
2019-09-19T18:44:35.538+0800	DEBUG	servicecenter/servicecenter.go:87	create service success orgServiceID= account-server, curServiceID = 80784229255ec96d90353e3c041bdf3586fdbbae
2019-09-19T18:44:35.538+0800	DEBUG	servicecenter/servicecenter.go:90	trying to do registration of instance, instanceID = 10.0.0.10:account-server:8090
2019-09-19T18:44:35.540+0800	DEBUG	servicecenter/sync.go:63	Registered instance successful, instanceID = 78bca3e2daca11e99638fa163eca30e0

Step 3: Results Verification

At this point, HelloServer gets the instance successfully, and calls the CheckHealth interface of AccountServer.
Open the website of Euraka and ServiceCenter respectively. Both service centers contain all the instance information.
Call the Login interface of HelloServer used the command line of curl,
```
$ curl -X POST \
http://192.168.88.75:8091/login \
-H 'Content-Type: application/json' \
-d '{
  "user":"Jack",
  "password":"123456"
}'
welcome Jack
```
HelloServer and AccountServer respectively print the following information.
AccountServer

HelloServer