Gateway fails to route according to the service name, and reports an error service unavailable, status=503

Remember the experience of a route forwarding failure

Use gateway+nacos,yaml The configuration is as follows , Here, the service name is used for forwarding ：

server:
  port: 10010

spring:
  application:
    name: @[email protected]
  cloud:
    nacos:
      server-addr: 127.0.0.1:8848 # nacos Address 

    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: blogtest #  Route identification , Must be unique 
          uri: lb://blogtest #  The destination address of the route ,lb by load balance, Load balancing 
          predicates: #  Route assertion , Determine whether the request meets the rules 
            - Path=/test/**  #  Determine whether the request is /user start 

pom The documents are as follows ：

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
</dependencies>

Then the service cannot be accessed , Has been an error

Whitelabel Error Page

This application has no configured error view, so you are seeing this as a fallback.

Wed May 18 15:38:29 CST 2022

[fd8c3a90-7] There was an unexpected error (type=Service Unavailable, status=503).

The key is that the console does not report an error , The normal kind , It makes me suspect that it's my own problem .

Later, I changed the routing address , Changed to use http Address forwarding ：

    gateway:
      routes:
        - id: blogtest
          uri: http://127.0.0.1:1236 #  It's changed here 
          predicates:
            - Path=/test/** 

Then send a request to the browser , succeed , Normal access .

After thinking for a while, I think it may be Nacos The version does not match the dependent version of my project , Go and Nacos Downgraded by a wave , It still doesn't work .

reason

See a blog later ：https://blog.csdn.net/qq_41953714/article/details/116239716

stay pom.xml A dependency is added to the file ：

<!-- Client load balancing loadbalancer-->
<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-loadbalancer</artifactId>
</dependency>

Restart , Sure enough .

The reason is to quote the original author

because springcloud2020 Abandoned Ribbon, therefore Alibaba stay 2021 edition nacos Deleted in Ribbon Of jar package , So it can't pass lb Route to specified microservices , There is 503 situation .

So just introduce springcloud loadbalancer Bag can