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This article shows you how to solve Spring Cloud service conflicts, the content is concise and easy to understand, it will definitely brighten your eyes. I hope you can get something through the detailed introduction of this article.

I. background

When we develop a micro-service architecture system, although each micro-service is isolated and can be developed separately, it is actually not the case. To debug and test your service, you not only need your micro-service to start and run, but also need its context services and dependent basic services to run; but if you have a large number of system services and dependencies, that is a thorny problem! Is there any way to improve the efficiency of development?

As shown in the figure above, can we deploy all the services with the server, and then the developer can only run the services that we are responsible for developing locally? because we need to rely on other services, locally started services also need to register with a public registry.

In the example, business service B has three instances registered in the registry.

They are: service, developer An and developer B start their own native

But in doing so, there will be new problems: services will conflict, meaning that developers A may jump to other people's instances (server, developer B) when debug their own business service B service.

Second, the solution.

An elegant way to solve this problem is to customize load balancing rules, which mainly achieve the following goals:

When an ordinary user visits a page on the server, all the requested routes only call the instance on the server

When developing An access, all requested routes call the instance started locally by Development A first, and if not, the instance on the server is called.

When developing B access is the same as above, all requested routes have priority to call the instance started locally by developer B, and if not, the instance on the server will be called.

III. Concrete realization

There are two key problems that need to be solved to achieve the above goals.

Distinguish service instances from different users

Implement custom load balancing rules

3.1. Distinguish service instances from different users

Just use the metadata (metadata) of the registry to distinguish.

Mainstream registries have metadata management.

Take Nacos as an example, you only need to add it under the configuration file

Spring: cloud: nacos: discovery: server-addr: localhost:8848 metadata: version: zlt

Version under metadata is the metadata I added. Key is version,value and zlt.

After starting the service, the metadata will be registered, as shown in the following figure

After metadata differentiation, the current situation is as follows

The instance version of the server is empty

The developer's own locally launched instance version is uniquely identified (his or her own name)

3.2. Custom load balancing rules

First of all, Ribbon is responsible for the load balancing of the instance in the Spring Cloud micro-service framework.

CustomIsolationRule class details can be found at: CustomIsolationRule.java

Public class CustomIsolationRule extends RoundRobinRule {/ * give priority to instance * / @ Override public Server choose (ILoadBalancer lb, Object key) {if (lb = = null) {return null;} String version = LbIsolationContextHolder.getVersion (); List targetList = null; List upList = lb.getReachableServers () If (StrUtil.isNotEmpty (version)) {/ / take the instance targetList of the specified version number targetList = upList.stream () .filter (server-> version.equals (NacosServer) server). GetMetadata () .get (CommonConstant.METADATA_VERSION))) .instances (Collectors.toList ()) } if (CollUtil.isEmpty (targetList)) {/ / only instances without version number targetList = upList.stream (). Filter (server-> {String metadataVersion = ((NacosServer) server). GetMetadata (). Get (CommonConstant.METADATA_VERSION); return StrUtil.isEmpty (metadataVersion);}) .instances (Collectors.toList ());} if (CollUtil.isNotEmpty (targetList)) {return getServer (targetList);} return super.choose (lb, key) } / * randomly take an instance * / private Server getServer (List upList) {int nextInt = RandomUtil.randomInt (upList.size ()); return upList.get (nextInt);}}

Integrate the polling rule RoundRobinRule to implement, the main logic is

According to the version number version entered upstream, if there is a value, the instance with the same version value in the service meta information will be taken.

If the upstream version number version has no value or the version number does not match any service, only the instance whose version value is empty in the service meta-information will be taken.

And whether to turn on the custom load rule is controlled by configuring the switch.

Configuration@ConditionalOnProperty (value = "zlt.ribbon.isolation.enabled", havingValue = "true") @ RibbonClients (defaultConfiguration = {RuleConfigure.class}) public class LbIsolationConfig {}

IV. Summary

The above-mentioned differentiated service instances and custom load rules are the core points of the whole solution, basically realizing the isolation of service instances, and the rest is how to transmit the upstream version. I will provide two ideas below.

The developer starts the front-end project by himself, and transmits version uniformly in the front-end project by configuring parameters.

Add to the header parameter when calling the interface through postman

The above content is how to resolve Spring Cloud service conflicts. Have you learned any knowledge or skills? If you want to learn more skills or enrich your knowledge reserve, you are welcome to follow the industry information channel.

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