About eruake learning

Four operating mechanisms :

1. register : Client connection server registration , Will register repeatedly , Until the registration is successful , After an error is reported, you will wait and register again

2. Pull : Every client 30 Seconds to pull the registry , To pull ( Use local cache ) The registry , New service start registration , Other modules need to wait 30 Seconds to be found

3. heartbeat : Every 30 Send an exception every second

A service , continuity 3 Failed to receive service heartbeat for times , Will delete his registration information

4. Self-protection model

Due to network interruption , A large number of servers have abnormal heartbeat ( The server and Eruake The network is down )

15 Within minutes ,85% There is a heartbeat exception on your server , Will enter self-protection mode , All registration information will not be deleted , Waiting for the network to recover

During development and debugging , You can disable protected mode , Avoid affecting the test

Client connection sp05 Registry Center , Add configuration

Eurake client

1. add to eureka-client

2.yml To configure :

eurake Connection address : http://eureka1:2001/eureka

/eureka Subpath

modify hosts file :win+r dervier

High availability

There is server downtime , The system can still be used , There is a backup server , Multiple servers can also be used for load balancing

The port numbers on different servers are the same and do not conflict .

To prevent downtime , The client connects to multiple servers defaultZone:XXX,XXX

Feign

 To configure :
 Which service to call   Order call   Goods and users   Need service id
 Which path to call   Define different methods to call different paths 
 Submit what parameters 

Feign Integrate Ribbon

Ribbon Provide load balancing and retry functions

feign Integrate Ribbon, Load balancing and retry are enabled by default

Retrying parameters :

MAxAutoRetries- Number of retries per server

Server replacement times

zull api gateway

Unified call entry : Just configure

1. newly build spring modular :sp06-zull

2.pom.xml add to eurake zull sp01-commonts

3.yml zuul:routes:item-service: /item-service/** 

4. Start the class to add comments :@EnableZuulProxy

Unified authority verification

No, token Access not allowed ,token It should be placed in http The header

1. New filter AccessFilter, Inherit ZuulFilter, And add @Component

Inherit Ribbon

Load balancing is enabled by default , Retrying is not enabled by default , Enable retry at gateway , It may double the pressure on the background server , Large area failure

Integrate Hystrix

System fault tolerance and current limiting tools

Fault tolerance : Fault tolerance through degradation , Downgrade ,zuul It is enabled by default Hystrix

Current limiting : Because the flow pressure is too high , Cause the background service to fail , Limiting current by fusing

10s achieve 20 Requests ( First satisfy ),50% Error executing degraded code --> The circuit breaker is on

When the circuit breaker opens , Half open , Try sending a client call to the server

The circuit breaker is fully automatic

1. use actuator expose Hystrix Monitoring data , yes springboot Provides a project monitoring indicator tool

spring All objects in the container

spring mvc All the paths

java Virtual machine heap memory mirroring