前言
ribbon是Netflix開源的用戶端負載均衡工具,ribbon實作一系列的負載均衡算法,通過這些負載均衡算法去查找相應的服務。ribbon被大家所熟知,可能是來源于spring cloud,今天就來聊聊如何單獨使用ribbon來實作業務用戶端負載均衡
實作關鍵
springcloud ribbon擷取服務清單是通過注冊中心,而單獨使用ribbon,因為沒有注冊中心加持,就得單獨配置服務清單
示例
1、在業務項目中pom引入ribbon GAV
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon</artifactId>
<version>2.2.2</version>
</dependency>
不過引進去,發現如果引入netfiix的相關的類,比如IPing,會發現引不進去,原因是因為這個GAV裡面依賴的jar的生命周期是runtime,即在運作期或者測試階段才生效,在編譯階段是不生效的。如果我們為了友善,可以直接單獨引入
spring cloud ribbon
<dependency>
<groupId>org.springframework.cloud</groupId>-->
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>-->
<version>2.2.2.RELEASE</version>
</dependency>
本文我們是想脫離springcloud,直接使用ribbon,是以我們可以直接 引入如下GAV
<!-- 核心的通用性代碼-->
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon-core</artifactId>
<version>${ribbon.version}</version>
</dependency>
<!-- 基于apache httpClient封裝的rest用戶端,內建了負載均衡子產品,内嵌http心跳檢測-->
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon-httpclient</artifactId>
<version>${ribbon.version}</version>
</dependency>
<!-- 負載均衡子產品-->
<dependency>
<groupId>com.netflix.ribbon</groupId>
<artifactId>ribbon-loadbalancer</artifactId>
<version>${ribbon.version}</version>
</dependency>
<!-- IClientConfig配置相關-->
<dependency>
<groupId>com.netflix.archaius</groupId>
<artifactId>archaius-core</artifactId>
<version>0.7.6</version>
</dependency>
<!-- IClientConfig配置相關-->
<dependency>
<groupId>commons-configuration</groupId>
<artifactId>commons-configuration</artifactId>
<version>1.8</version>
</dependency>
2、建立ribbon中繼資料配置類
@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class RuleDefinition {
/**
* 服務名稱
*/
private String serviceName;
/**
* 命名空間,當服務名相同時,可以通過namesapce來進行隔離區分
* 未指定預設為public
*/
@Builder.Default
private String namespace = DEFAULT_NAMESPACE;
/**
* 自定義負載均衡政策,未指定預設為輪詢
*/
@Builder.Default
private String loadBalancerRuleClassName = RoundRobin;
/**
* 自定義心跳檢測,未指定不檢測
*/
@Builder.Default
private String loadBalancerPingClassName = DummyPing;
/**
* 服務清單,多個用英文逗号隔開
*/
private String listOfServers;
/**
* 該優先級大于loadBalancerPingClassName
*/
private IPing ping;
/**
* 心跳間隔,不配置預設是10秒,機關秒
*/
private int pingIntervalSeconds;
/**
* 該優先級大于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、建立負載均衡工廠【核心實作】
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)){
// 無法通過ConfigurationManager.getConfigInstance().setProperty(serviceName + DOT + namespace + DOT + PING_CLASS_NAME, ruleDefinition.getLoadBalancerPingClassName());
//LoadBalancerBuilder沒提供通過ClientConfig配置ping方法,隻能通過withPing修改
ping = getPing(serviceName,namespace);
}
IRule rule = ruleDefinition.getRule();
if(ObjectUtils.isEmpty(rule)){
// 也可以通過ConfigurationManager.getConfigInstance().setProperty(serviceName + DOT + namespace + DOT + RULE_CLASS_NAME, ruleDefinition.getLoadBalancerRuleClassName());
rule = getRule(serviceName,namespace);
}
// 配置服務清單
ConfigurationManager.getConfigInstance().setProperty(serviceName + DOT + namespace + DOT + SERVER_LIST, ruleDefinition.getListOfServers());
// 因為服務清單目前是配置寫死,是以關閉清單更新,否則當觸發定時更新時,會重新将服務清單狀态恢複原樣,這樣會導緻server的isLive狀态不準确
// 不設定預設采用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){
// 預設每隔10秒進行心跳檢測
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;
}
/**
* 擷取 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);
}
/**
* 擷取 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;
}
核心實作類:com.netflix.loadbalancer.LoadBalancerBuilder 利用該類建立相應的負載均衡
4、測試
a、 新起2個服務提供者占用6666端口、和6667端口
b、 在消費端的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、 測試類
@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);
}
}
當服務提供者都正常提供服務時,觀察控制台
可以觀察以輪詢的方式調用服務提供者,當斷掉其中一台服務提供者時,再觀察控制台
會發現隻調用服務正常的那台
總結
獨立使用ribbon其實不會很難,主要對LoadBalancerBuilder這個API熟悉就可以定制自己想要的負載均衡器。springcloud從2020版本就将ribbon廢棄了,轉而要扶持其親兒子loadbalancer,就目前功能而言,loadbalancer還沒ribbon豐富,通過本文紀念一下被springcloud遺棄的ribbon
demo連結
https://github.com/lyb-geek/springboot-learning/tree/master/springboot-ribbon-loadbalance