這個重寫的輪詢跟原始碼的輪詢一樣嗎？
int nextServerIndex = incrementAndGetModulo(serverCount);
我感覺原始碼的這個陳述句應該是獲取服務對應的集群索引，然后再去得到索引對應的集群給提供的埠，但是他這里卻說的是回傳提供的次數
。。。
/*
*
* Copyright 2013 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.netflix.loadbalancer;
import com.netflix.client.config.IClientConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
/**
* The most well known and basic load balancing strategy, i.e. Round Robin Rule.
*
* @author stonse
* @author Nikos Michalakis <[email protected]>
*
*/
public class RoundRobinRule extends AbstractLoadBalancerRule {
private AtomicInteger nextServerCyclicCounter;
private static final boolean AVAILABLE_ONLY_SERVERS = true;
private static final boolean ALL_SERVERS = false;
private static Logger log = LoggerFactory.getLogger(RoundRobinRule.class);
public RoundRobinRule() {
nextServerCyclicCounter = new AtomicInteger(0);
}
public RoundRobinRule(ILoadBalancer lb) {
this();
setLoadBalancer(lb);
}
public Server choose(ILoadBalancer lb, Object key) {
if (lb == null) {
log.warn("no load balancer");
return null;
}
Server server = null;
int count = 0;
while (server == null && count++ < 10) {
List<Server> reachableServers = lb.getReachableServers();
List<Server> allServers = lb.getAllServers();
int upCount = reachableServers.size();
int serverCount = allServers.size();
if ((upCount == 0) || (serverCount == 0)) {
log.warn("No up servers available from load balancer: " + lb);
return null;
}
int nextServerIndex = incrementAndGetModulo(serverCount);
server = allServers.get(nextServerIndex);
if (server == null) {
/* Transient. */
Thread.yield();
continue;
}
if (server.isAlive() && (server.isReadyToServe())) {
return (server);
}
// Next.
server = null;
}
if (count >= 10) {
log.warn("No available alive servers after 10 tries from load balancer: "
+ lb);
}
return server;
}
/**
* Inspired by the implementation of {@link AtomicInteger#incrementAndGet()}.
*
* @param modulo The modulo to bound the value of the counter.
* @return The next value.
*/
private int incrementAndGetModulo(int modulo) {
for (;;) {
int current = nextServerCyclicCounter.get();
int next = (current + 1) % modulo;
if (nextServerCyclicCounter.compareAndSet(current, next))
return next;
}
}
@Override
public Server choose(Object key) {
return choose(getLoadBalancer(), key);
}
@Override
public void initWithNiwsConfig(IClientConfig clientConfig) {
}
}
uj5u.com熱心網友回復：
尷尬了，沒看到他重寫的方法里是先+上去然后再除，還以為是除了然后出來再除，沒事了。。。大家散了，下一個出現的人直接給分了
轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/165226.html
標籤：Java EE
上一篇：元素放入HashMap的原理?元素放入HashSet的實作原理? HashMap和Hashtable有什么區別?
下一篇：ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING在mybatis中報sql injection