Nacos Service discovery data model

1. Namespace Isolation design

Namespace **(Namespace)** For tenant granularity isolation ,Namespace One of the most common scenarios is the isolation of different environments , For example, development testing

The environment and the resources of the production environment （ Such as configuration 、 service ） Isolation etc. .

From a tenant ( user ) From the perspective of , If there are many different environments , At this time, you can create different

namespce, In order to achieve multi environment isolation . for example , You may have development , Three different environments for testing and production , Then use a set of

nacos There are three different clusters namespace. As shown in the figure below ：

From multiple tenants ( user ) From the perspective of , Every tenant ( user ) It may have its own namespace, Every tenant ( user ) Configuration data and notes

The service data of the volume will belong to its own namespace Next , To achieve data isolation among multi tenants . For example, the super administrator assigned three

Tenants , They are Zhang San 、 Li Si and Wang Wu . After the distribution , All tenants log in with their own account name and password , Create your own naming

Space . As shown in the figure below ：

2. Namespace Management

I've already introduced , Namespace (Namespace) Is used to isolate multiple environments （ Such as development 、 test 、 production ）, And each application is in a different ring

The same configuration of the environment （ Such as database data source ） The values are different . therefore , We should aim at the actual R & D process of enterprise projects 、 Environmental planning .

For example, a software company has developed 、 test 、 Three sets of production environment , We should establish three environments respectively namespace.

Establish all namespace after , stay Configuration Management And Service management All pages under the module , Will contain for switching namespace( Environmental Science ) Of tab Button , Here's the picture ：

Be careful : namesace by public yes nacos A reserved space for , If you need to create your own namespace, Do not mix public The nuptial , It is named after a real business scenario with specific semantics , So as not to make it literally difficult to distinguish which one you are namespace.

Be careful ： When writing the program to get the configuration set , designated namespace Parameters must be filled Namespace ID, Not the name

for example ：

3. Data model

Nacos After years of production experience in Alibaba, the data model is refined , It's a service - colony - Three layer model of instance , This can basically meet the data storage and management of services in all scenarios .

nacos The data model of service discovery is as follows ：

• service ： Software functions provided to the outside world , Access predefined interfaces over the network .

• service name ： Identification of service delivery , Through this identification, the service to be accessed can be uniquely determined .

• example ： Providing one or more services with an accessible network address （IP:Port） The process of , Start a service , There is a service instance .

• Meta information ：Nacos data （ Such as configuration and service ） Description information , Such as service version 、 The weight 、 Disaster recovery strategy 、 Load balancing strategy 、 Authentication configuration 、 Various custom tags (label), In terms of scope of action , Meta information divided into service levels 、 Meta information of cluster and instance .

• colony A collection of service instances , Service instances form a default cluster , Clusters can be further divided into requirements , The unit of partition can be virtual cluster , Only instances in the same cluster can perceive each other .

The data model shows that ： Application passed Namespace、Service、Cluster(DEFAULT) Configuration of , Describes the environment to which the service is directed （ Such as development environment ） Which cluster do you belong to

Registration instance .

Configure the hierarchy as shown in the figure below ：

The specific application example is shown below ：

If some examples of the company are distributed in different computer rooms all over the country , for example ：

xxx.xxx.xxx.xxx:8081, In Shanghai
xxx.xxx.xxx.xxx:8082, In Shanghai
xxx.xxx.xxx.xxx:8083, In Hangzhou computer room

Nacos The instance in the same machine room Divided into a cluster . in other words ,userService It's the service name , A service can be composed of multiple service clusters , For example, Hangzhou cluster 、 Shanghai cluster , And there can be multiple service instances under each cluster , Form a hierarchical model , Pictured ：

When microservices access each other , You should visit as much as possible The same cluster Service instance under , Because local access under the same cluster is faster . When not available in this cluster , To access other clusters . for example ：

In Hangzhou computer room orderService Priority should be given to accessing the same computer room userService, If in Hangzhou machine room userService Services are not available , Will call the userService.

The specific code application example is shown below ：

Appoint namespace Of id：f5eec3c1-4f05-40cd-964a-c8d44f342ab4（ Pay attention to setting according to your own environment namespace Of id）

Specify cluster name ：DEFAULT Represents the default cluster , Not required

spring:
  application:
    name: transaction‐service
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
        namespace: f5eec3c1-4f05-40cd-964a-c8d44f342ab4

Be careful : Cluster as instance isolation , Only instances of the same cluster can perceive each other .

Be careful : namespace、cluster-name If it is not filled in, the default value will be adopted ,namespace The default is public Namespace , cluster-name The default value is DEFAULT colony .