我使用的是不带Eureka的Ribbon。我使用的是ConfigurationBasedServerList来提供服务器实例的列表,如下所示。
customerinfo.ribbon.listOfServers=localhost:9003,localhost:9008
我已使用/ health端点配置PingURL。我还配置了AvailabilityFilteringRule,它需要过滤不可用的服务器实例。像这样..
public class RibbonConfig {
@Autowired
IClientConfig ribbonClientConfig;
@Bean
public IPing ribbonPing(IClientConfig config) {
return new PingUrl(true, "/health");
}
@Bean
public IRule ribbonRule(IClientConfig config) {
return new AvailabilityFilteringRule();
}
}
这通常效果很好。在一种情况下,它不能很好地工作。在端口9008上运行的服务器实例关闭时,情况就是这样。
让我解释一些调试消息。
DEBUG com.netflix.loadbalancer.DynamicServerListLoadBalancer - List of Servers for customerinfo obtained from Discovery client: [localhost:9003, localhost:9008]
DEBUG com.netflix.loadbalancer.DynamicServerListLoadBalancer - Filtered List of Servers for customerinfo obtained from Discovery client: [localhost:9003, localhost:9008]
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: clearing server list (SET op)
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: addServer [localhost:9003]
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: addServer [localhost:9008]
com.netflix.loadbalancer.DynamicServerListLoadBalancer - Setting server list for zones: {unknown=[localhost:9003, localhost:9008]}
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: clearing server list (SET op)
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: addServer [localhost:9003]
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: addServer [localhost:9008]
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: forceQuickPing invoked
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: PingTask executing [2] servers configured
DEBUG com.netflix.loadbalancer.BaseLoadBalancer - LoadBalancer: Server [localhost:9008] status changed to DEAD
查看DEBUG消息。遵循的过程如下所示:1)清除服务器列表,然后再次从配置中添加服务器。2)对他们的状态进行Ping。3)根据ping结果更新可用的服务器列表。
似乎每隔30秒就会发生上述过程,以维护DynamicServerList。
现在,问题是-从第一个log语句到倒数第二个log语句,ribbon认为两个服务器实例均可用。因此,如果在此时间内出现负载平衡请求,则可能会将其发送到服务器localhost:9008,该服务器处于DOWN状态。
据我了解,Ribbon库未保留PingStatistics。我认为该库依靠Eureka之类的服务发现工具来提供DynamicServerlist,该服务取决于某些运行状况检查是否正常。
现在,要解决此问题,我可以开始使用Eureka,并且此问题可能会消失。我不想使用Eureka,因为我的环境不会经常增长/缩小...它几乎是静态的。
我在这里缺少配置吗?我们如何解决这个问题?
我正在使用“ spring-cloud-starter-ribbon”版本1.2.6.RELEASE。
@Slf4j
public class LoadBalanceConfig {
@Bean
public IClientConfig ribbonClientConfig() {
DefaultClientConfigImpl config = new DefaultClientConfigImpl();
config.set(IClientConfigKey.Keys.IsSecure, false);
config.set(IClientConfigKey.Keys.ListOfServers, XXXXXXX);
config.set(IClientConfigKey.Keys.ServerListRefreshInterval, 3000);
return config;
}
@Bean
public ServerList<Server> ribbonServerList(IClientConfig clientConfig) {
AbstractServerList<Server> lst = new ConfigurationBasedServerList();
lst.initWithNiwsConfig(clientConfig);
return lst;
}
@Bean
public ServerListFilter<Server> ribbonServerListFilter() {
return new AbstractServerListFilter<Server>() {
@Override
public List<Server> getFilteredListOfServers(List<Server> servers) {
return servers;
}
};
}
// modified from com.netflix.loadbalancer.RoundRobinRule
public static class RoundRobinRule implements IRule {
private ILoadBalancer lb;
private AtomicInteger nextServerCyclicCounter = new AtomicInteger(0);
@Override
public void setLoadBalancer(ILoadBalancer lb) {
this.lb = lb;
}
@Override
public ILoadBalancer getLoadBalancer() {
return lb;
}
@Override
public Server choose(Object key) {
ILoadBalancer lb = getLoadBalancer();
if (lb == null) {
log.warn("no load balancer");
return null;
}
List<Server> reachableServers = lb.getReachableServers();
int upCount = reachableServers.size();
if (upCount == 0) {
log.warn("No up servers available from load balancer: " + lb);
return null;
}
int nextServerIndex = incrementAndGetModulo(upCount);
return reachableServers.get(nextServerIndex);
}
private int incrementAndGetModulo(int modulo) {
for (;;) {
int current = nextServerCyclicCounter.get();
int next = (current + 1) % modulo;
if (nextServerCyclicCounter.compareAndSet(current, next)) {
return next;
}
}
}
}
@Bean
public IRule ribbonRule() {
return new RoundRobinRule();
}
@Bean
public IPing ribbonPing() {
PingUrl ping = new PingUrl(false, "/XXXactive_detect");
ping.setExpectedContent("{\"status\":\"OK\"}");
return ping;
}
@Bean
public ILoadBalancer ribbonLoadBalancer(IClientConfig clientConfig, IRule rule, IPing ping,
ServerList<Server> serverList, ServerListFilter<Server> filter, ServerListUpdater serverListUpdater) {
DynamicServerListLoadBalancer<Server> loadBalancer = new DynamicServerListLoadBalancer<>(clientConfig, rule,
ping, serverList, filter, serverListUpdater);
return loadBalancer;
}
@Bean
public ServerListUpdater ribbonServerListUpdater(IClientConfig clientConfig) {
return new PollingServerListUpdater(clientConfig);
}
}