title: Mersher Quick Start lang: en ref: mersher-quick-start permalink: /docs/mersher-quick-start/ excerpt: Describe how to use mersher to merge into the servicecomb microservice system last_modified_at: 2019-08-08T14:01:43.000Z

Install Go and Python development environment

Run Service Center

In the ServiceComb microservices framework, Service Center provides service registration and service discovery, which can be run directly using Docker.

docker pull servicecomb/service-center
docker run -d -p 30100:30100 servicecomb/service-center:latest

Reference to service center deployment to learn deploying Service Center and front as a local binary.

Use mersher to merge into the servicecomb microservice system

Background

  • This use case is mainly to help users get started quickly with mersher sidecar mode. We hope that users can understand the working mode of mersher and learn how to merge the existing http service into the ServiceComb micro-service system with mersher's help. The final goal is to help user get the micro-service capabilities such as load balancing, flow control, service management and call chain tracing provided by servicecomb. The full case will be submitted to Case Download.

Mersher use case service introduction

  • 1 httpserver-a: A http server based on golang which is for BMI calculator and can be developed by any language.

  • 2 httpserver-b: A http server based on python which is for BMI calculator and can be developed by any language.

  • 3 mersher-a: A mersher instance which serves for httpserver-a via sidecar mode.

  • 4 mersher-b: A mersher instance which serves for httpserver-b via sidecar mode.

  • 5 mersher-g: A mersher instance which serves for httpserver-gateway via sidecar mode.

  • 6 servicecenter: Servicecenter which receives registration of mesher service and provides services as service discovery, routing query, service monitoring and so on.

  • 7 webapp: A http server which reuses the bmi example service is used for displaying visual results on the browser and using ajax to execute http service calls.

  • 8 httpserver-gateway: A http server which is used as an unified export of internal services receives webapp's requestand and then execute HTTP request as a BMI client.

    mersher deployment diagram

Process details

  • 1 The browser execute a http call via the webapp service http://192.168.88.64:4538/bmi.

  • 2 The httpserver-gateway service receives the request and execute http call http://mersher-provider/bmi. Because the proxy is set as http://127.0.0.1:30101, the request initiated by httpserver-gateway will be forwarded to the mersher-g service.

  • 3 mersher-g gets the address of the service name from the servicecenter based on the requested service name(the service name mersher-provider here is configured in microservice.yaml) and forwarded to one of the two mersher (mersher-a and mersher-b) according to the load balancing algorithm (default polling);

  • 4 mersher (mersher-a and mersher-b) services forward http requests to their own provider service (httpserver_a or httpserver_b) based on the spefic address.

  • 5 httpserver_a and httpserver_b will calculate according to the user's height and weight, and return their own service ID displayed on the interface. The flow chart is as follows:

    mersher-flow-chart

Environmental construction

  • 1 Compile mersher in download. Download the project by README.md to get the executable mersher(linux) or mersher.exe(windows).

  • 2 Create mersher-g to receive client requests. In the mersher directory execute the following linux command to create mersher-g. In order to the execute mersher you also need to copy the conf.

    mkdir /usr/local/src/mersher-g
cp ./mesher /usr/local/src/mersher-g
cp -r ./conf /usr/local/src/mersher-g

    Change service name in microservice.yaml from hellemesher to mersher-consumer. Change the listening service address in chassis.yaml from 127.0.0.1 to intranet ip（Viewed by cmd ifconfig in linux, such as 192.168.88.64）:

    listenAddress: 127.0.0.1:40101  -----》  listenAddress: 192.168.88.64:40101
listenAddress: 127.0.0.1:30101  -----》  listenAddress: 192.168.88.64:30101
listenAddress: 127.0.0.1:30102  -----》  listenAddress: 192.168.88.64:30102

  • 3 Create mersher-a and mersher-b services.

    mkdir /usr/local/src/mersher-a
cp ./mesher /usr/local/src/mersher-a
cp -r ./conf /usr/local/src/mersher-a
mkdir /usr/local/src/mersher-b
cp ./mesher /usr/local/src/mersher-b
cp -r ./conf /usr/local/src/mersher-b

    Change the service name in microservice.yaml from hellemesher to mersher-provider for both mersher-a and mersher-b
    Change the listening address and port set in the mersher-a configuration file chassis.yaml:

    listenAddress: 127.0.0.1:40101  -----》  listenAddress: 192.168.88.64:40107
listenAddress: 127.0.0.1:30101  -----》  listenAddress: 192.168.88.64:30111
listenAddress: 127.0.0.1:30102  -----》  listenAddress: 192.168.88.64:30112

    Change the listening address and port set in the mersher-b configuration file chassis.yaml:

      listenAddress: 127.0.0.1:40101  -----》  listenAddress: 192.168.88.64:40102
  listenAddress: 127.0.0.1:30101  -----》  listenAddress: 192.168.88.64:30108
  listenAddress: 127.0.0.1:30102  -----》  listenAddress: 192.168.88.64:30109

  • 4 Start running mersher-g, mersher-a and mersher-b respectively by cmd.

    cd /usr/local/src/mersher-a
export SPECIFIC_ADDR=127.0.0.1:4537
./mersher

    cd /usr/local/src/mersher-b
export SPECIFIC_ADDR=127.0.0.1:4540
./mersher

    cd /usr/local/src/mersher-g
./mersher

  • 5 Use httpserver to provide http service. Use httpserver-gateway as the client to execute http request to httpserver.

    go build httpserver.go
./httpserver.go
go build httpservergateway.go
./httpservergateway

  • 6 Run http_server.py program. You need to install python2.7 and this service relies on BaseHTTPServer package.

  • 7 Use webapp as a user interface which is in Bmi-example. Edit http address of the ajax call from /calculator/bmi?height= to http://192.168.88.64:4538/bmi?height= in static page webapp/src/main/resources/static/index.html. This address is the listening address of the httpservergateway. Update the listening port configuration in application.yaml to 192.168.88.64.

Start testing

What's next