前言
ribbon是Netflix开源的客户端负载均衡工具,ribbon实现一系列的负载均衡算法,通过这些负载均衡算法去查找相应的服务。ribbon被大家所熟知,可能是来源于spring cloud,今天就来聊聊如何单独使用ribbon来实现业务客户端负载均衡
实现关键
springcloud ribbon获取服务列表是通过注册中心,而单独使用ribbon,因为没有注册中心加持,就得单独配置服务列表
示例
1、在业务项目中pom引入ribbon GAV
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon</artifactId>
<version>2.2.2</version>
</dependency>
不过引进去,发现如果引入netfiix的相关的类,比如IPing,会发现引不进去,原因是因为这个GAV里面依赖的jar的生命周期是runtime,即在运行期或者测试阶段才生效,在编译阶段是不生效的。如果我们为了方便,可以直接单独引入
spring cloud ribbon
<dependency>
<groupId>org.springframework.cloud</groupId>-->
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>-->
<version>2.2.2.RELEASE</version>
</dependency>
本文我们是想脱离springcloud,直接使用ribbon,因此我们可以直接 引入如下GAV
<!-- 核心的通用性代码-->
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon-core</artifactId>
<version>${ribbon.version}</version>
</dependency>
<!-- 基于apache httpClient封装的rest客户端,集成了负载均衡模块,内嵌http心跳检测-->
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon-httpclient</artifactId>
<version>${ribbon.version}</version>
</dependency>
<!-- 负载均衡模块-->
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon-loadbalancer</artifactId>
<version>${ribbon.version}</version>
</dependency>
<!-- IClientConfig配置相关-->
<dependency>
<groupId>com.netflix.archaius</groupId>
<artifactId>archaius-core</artifactId>
<version>0.7.6</version>
</dependency>
<!-- IClientConfig配置相关-->
<dependency>
<groupId>commons-configuration</groupId>
<artifactId>commons-configuration</artifactId>
<version>1.8</version>
</dependency>
2、创建ribbon元数据配置类
@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class RuleDefinition {
/**
* 服务名称
*/
private String serviceName;
/**
* 命名空间,当服务名相同时,可以通过namesapce来进行隔离区分
* 未指定默认为public
*/
@Builder.Default
private String namespace = DEFAULT_NAMESPACE;
/**
* 自定义负载均衡策略,未指定默认为轮询
*/
@Builder.Default
private String loadBalancerRuleClassName = RoundRobin;
/**
* 自定义心跳检测,未指定不检测
*/
@Builder.Default
private String loadBalancerPingClassName = DummyPing;
/**
* 服务列表,多个用英文逗号隔开
*/
private String listOfServers;
/**
* 该优先级大于loadBalancerPingClassName
*/
private IPing ping;
/**
* 心跳间隔,不配置默认是10秒,单位秒
*/
private int pingIntervalSeconds;
/**
* 该优先级大于loadBalancerRuleClassName
*/
private IRule rule;
}
@Data
@AllArgsConstructor
@NoArgsConstructor
@ConfigurationProperties(prefix = PREFIX)
public class LoadBalanceProperty {
public static final String PREFIX = "lybgeek.loadbalance";
private List<RuleDefinition> rules;
public Map<String,RuleDefinition> getRuleMap(){
if(CollectionUtils.isEmpty(rules)){
return Collections.emptyMap();
}
Map<String,RuleDefinition> ruleDefinitionMap = new LinkedHashMap<>();
for (RuleDefinition rule : rules) {
String key = rule.getServiceName() + RULE_JOIN + rule.getNamespace();
ruleDefinitionMap.put(key,rule);
}
return Collections.unmodifiableMap(ruleDefinitionMap);
}
}
3、创建负载均衡工厂【核心实现】
private final LoadBalanceProperty loadBalanceProperty;
// key:serviceName + nameSpace
private static final Map<String, ILoadBalancer> loadBalancerMap = new ConcurrentHashMap<>();
public ILoadBalancer getLoadBalancer(String serviceName,String namespace){
String key = serviceName + RULE_JOIN + namespace;
if(loadBalancerMap.containsKey(key)){
return loadBalancerMap.get(key);
}
RuleDefinition ruleDefinition = getAvailableRuleDefinition(serviceName,namespace);
IPing ping = ruleDefinition.getPing();
if(ObjectUtils.isEmpty(ping)){
// 无法通过ConfigurationManager.getConfigInstance().setProperty(serviceName + DOT + namespace + DOT + PING_CLASS_NAME, ruleDefinition.getLoadBalancerPingClassName());
//LoadBalancerBuilder没提供通过ClientConfig配置ping方法,只能通过withPing修改
ping = getPing(serviceName,namespace);
}
IRule rule = ruleDefinition.getRule();
if(ObjectUtils.isEmpty(rule)){
// 也可以通过ConfigurationManager.getConfigInstance().setProperty(serviceName + DOT + namespace + DOT + RULE_CLASS_NAME, ruleDefinition.getLoadBalancerRuleClassName());
rule = getRule(serviceName,namespace);
}
// 配置服务列表
ConfigurationManager.getConfigInstance().setProperty(serviceName + DOT + namespace + DOT + SERVER_LIST, ruleDefinition.getListOfServers());
// 因为服务列表目前是配置写死,因此关闭列表更新,否则当触发定时更新时,会重新将服务列表状态恢复原样,这样会导致server的isLive状态不准确
// 不设置默认采用com.netflix.loadbalancer.PollingServerListUpdater
ConfigurationManager.getConfigInstance().setProperty(serviceName + DOT + namespace + DOT + SERVERLIST_UPDATER_CLASS_NAME, EmptyServerListUpdater.class.getName());
IClientConfig config = new DefaultClientConfigImpl(namespace);
config.loadProperties(serviceName);
ZoneAwareLoadBalancer<Server> loadBalancer = getLoadBalancer(config, ping, rule);
loadBalancerMap.put(key,loadBalancer);
if(ruleDefinition.getPingIntervalSeconds() > 0){
// 默认每隔10秒进行心跳检测
loadBalancer.setPingInterval(ruleDefinition.getPingIntervalSeconds());
}
return loadBalancer;
}
public ZoneAwareLoadBalancer<Server> getLoadBalancer(IClientConfig config, IPing ping, IRule rule){
ZoneAwareLoadBalancer<Server> serverZoneAwareLoadBalancer = LoadBalancerBuilder.newBuilder()
.withClientConfig(config)
.withPing(ping)
.withRule(rule)
.buildDynamicServerListLoadBalancerWithUpdater();
return serverZoneAwareLoadBalancer;
}
/**
* 获取 iping
* @param serviceName
* @param namespace
* @return
*/
@SneakyThrows
public IPing getPing(String serviceName, String namespace){
RuleDefinition ruleDefinition = getAvailableRuleDefinition(serviceName,namespace);
Class<?> loadBalancerPingClass = ClassUtils.forName(ruleDefinition.getLoadBalancerPingClassName(), Thread.currentThread().getContextClassLoader());
Assert.isTrue(IPing.class.isAssignableFrom(loadBalancerPingClass),String.format("loadBalancerPingClassName : [%s] is not Iping class type",ruleDefinition.getLoadBalancerPingClassName()));
return (IPing) BeanUtils.instantiateClass(loadBalancerPingClass);
}
/**
* 获取 loadbalanceRule
* @param serviceName
* @param namespace
* @return
*/
@SneakyThrows
public IRule getRule(String serviceName, String namespace){
RuleDefinition ruleDefinition = getAvailableRuleDefinition(serviceName,namespace);
Class<?> loadBalancerRuleClass = ClassUtils.forName(ruleDefinition.getLoadBalancerRuleClassName(), Thread.currentThread().getContextClassLoader());
Assert.isTrue(IRule.class.isAssignableFrom(loadBalancerRuleClass),String.format("loadBalancerRuleClassName : [%s] is not Irule class type",ruleDefinition.getLoadBalancerRuleClassName()));
return (IRule) BeanUtils.instantiateClass(loadBalancerRuleClass);
}
private RuleDefinition getAvailableRuleDefinition(String serviceName,String namespace){
Map<String, RuleDefinition> ruleMap = loadBalanceProperty.getRuleMap();
Assert.notEmpty(ruleMap,"ruleDefinition is empty");
String key = serviceName + RULE_JOIN + namespace;
RuleDefinition ruleDefinition = ruleMap.get(key);
Assert.notNull(ruleDefinition,String.format("NOT FOUND AvailableRuleDefinition with serviceName : [{}] in namespace:[{}]",serviceName,namespace));
return ruleDefinition;
}
核心实现类:com.netflix.loadbalancer.LoadBalancerBuilder 利用该类创建相应的负载均衡
4、测试
a、 新起2个服务提供者占用6666端口、和6667端口
b、 在消费端的application.yml配置如下内容
lybgeek:
loadbalance:
rules:
- serviceName: provider
namespace: test
loadBalancerPingClassName: com.github.lybgeek.loadbalance.ping.TelnetPing
pingIntervalSeconds: 3
# loadBalancerRuleClassName: com.github.lybgeek.loadbalance.rule.CustomRoundRobinRule
listOfServers: 127.0.0.1:6666,127.0.0.1:6667
c、 测试类
@Override
public void run(ApplicationArguments args) throws Exception {
ServerChooser serverChooser = ServerChooser.builder()
.loadBalancer(loadbalanceFactory.getLoadBalancer("provider", "test"))
.build();
while(true){
Server reachableServer = serverChooser.getServer("provider");
if(reachableServer != null){
System.out.println(reachableServer.getHostPort());
}
TimeUnit.SECONDS.sleep(1);
}
}
当服务提供者都正常提供服务时,观察控制台
可以观察以轮询的方式调用服务提供者,当断掉其中一台服务提供者时,再观察控制台
会发现只调用服务正常的那台
总结
独立使用ribbon其实不会很难,主要对LoadBalancerBuilder这个API熟悉就可以定制自己想要的负载均衡器。springcloud从2020版本就将ribbon废弃了,转而要扶持其亲儿子loadbalancer,就目前功能而言,loadbalancer还没ribbon丰富,通过本文纪念一下被springcloud遗弃的ribbon
demo链接
https://github.com/lyb-geek/springboot-learning/tree/master/springboot-ribbon-loadbalance
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