From monolithic application to microservice framework

challenges:

1. version control 

After testing the branch A, pull the latest code(merged B) -> confilcts ? no conflicts? -> regression testing 

2. change to go language

3. upgrade the library go1.12-go1.13
4. only one testing server waiting for multi testing tasks

pain points due to strong dependency

 service isolation solves code duplication

micro-service:

MQ to acchieve service decoupling via asyn msg communication 

independent database per service, isolation

each service deployed on the web can only be accessed through PORT

Exposing external interface： HTTP

exposing internal interface: rpc

-> layered architecture

support multi -language

blueprint of microservice

 gateway: each kind of web service may contain a cluster with ips and port -> we need router, and registration center --> healthy service discovery -> get ip and port

1,router 2.service discovery 3.authentication 4.fuse (two many requests) 5.ip blacklist/whiltelist 6. load balancer

inner service register at the registration center using ip/port

web -> service discovery -> get healthy service's ip/port(a kind of srv may be a cluster) -> to web -> connect to that service

configuration center: without it, if we have to change certain config in one srv, we need to restart that srv, causing other srvs to fail

-> read from one place can solve this problem

link tracing: a transaction may span many services,  easy to troubleshoot the error