您好,登錄后才能下訂單哦!
這篇文章主要介紹Storm-kafka中如何封裝DynamicBrokerReader類,文中介紹的非常詳細(xì),具有一定的參考價值,感興趣的小伙伴們一定要看完!
在細(xì)節(jié)上把握 DynamicBrokerReder的封裝類 - ZkBrokerReader
package com.mixbox.storm.kafka.trident; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.mixbox.storm.kafka.DynamicBrokersReader; import com.mixbox.storm.kafka.ZkHosts; import java.util.Map; /** * 2014/07/22 * 在ZK中間拿到 GlobalPartitionInformation * * ZkBrokerReader 是對于DynamicBrokersReader的一個簡單的封裝 * @author Yin Shuai */ public class ZkBrokerReader implements IBrokerReader { public static final Logger LOG = LoggerFactory .getLogger(ZkBrokerReader.class); GlobalPartitionInformation cachedBrokers; DynamicBrokersReader reader; long lastRefreshTimeMs; long refreshMillis; /** * * @param conf * @param topic * 指定topic的zkBrokerReader * @param hosts */ public ZkBrokerReader(Map conf, String topic, ZkHosts hosts) { reader = new DynamicBrokersReader(conf, hosts.brokerZkStr, hosts.brokerZkPath, topic); cachedBrokers = reader.getBrokerInfo(); lastRefreshTimeMs = System.currentTimeMillis(); refreshMillis = hosts.refreshFreqSecs * 1000L; } @Override public GlobalPartitionInformation getCurrentBrokers() { long currTime = System.currentTimeMillis(); // 很簡單, 指定了你多長時間開始去刷新Brokerlibiao if (currTime > lastRefreshTimeMs + refreshMillis) { LOG.info("brokers need refreshing because " + refreshMillis + "ms have expired"); cachedBrokers = reader.getBrokerInfo(); lastRefreshTimeMs = currTime; } return cachedBrokers; } @Override public void close() { reader.close(); } }
總覽我們的Code :
ZkBrokerReader 是對于 DynamicBrokersReader的一個簡單封裝,ZkBrokerReader之中持有2個主要的Class
1 GlobalPartitionInformatio cachedBroker;
2 DynamicBrokersReader reader;
3 long lastRefreshTimeMs; 最新的刷新時間
lastRefreshTimeMs = System.currentTimeMillis(); 最新的刷新時間為系統(tǒng)的當(dāng)前時間
4 long refreshMillis
refreshMillis = host.refreshFreqSecs * 1000L 設(shè)定刷新的毫秒數(shù)為
5
public GlobalPartitionInformation getCurrentBrokers() { long currTime = System.currentTimeMillis(); // 很簡單, 指定了你多長時間開始去刷新Brokerlibiao if (currTime > lastRefreshTimeMs + refreshMillis) { LOG.info("brokers need refreshing because " + refreshMillis + "ms have expired"); cachedBrokers = reader.getBrokerInfo(); lastRefreshTimeMs = currTime; } return cachedBrokers; }
每一次調(diào)用getCurrentBrokers,首先會取System.currentTimeMillis 當(dāng)當(dāng)前的系統(tǒng)時間超過了 最早的刷新時間+刷新
的間隔,就會再次的去跟新:
cachedBrokers = reader.getBrokerInfo(); getBrokerInfo()方法每調(diào)用一次,也就重新在zk之中重新去取
一次。
ZkBrokerReader是對于DynamicBrokerReader的一個封裝,DynamicBrokerReader的Dynamic性質(zhì)并不程序動態(tài)的因數(shù),而只是簡單在讀取ZK數(shù)據(jù)的過程之中,Zk數(shù)據(jù)已經(jīng)動態(tài)的發(fā)生變化?
以上是“Storm-kafka中如何封裝DynamicBrokerReader類”這篇文章的所有內(nèi)容,感謝各位的閱讀!希望分享的內(nèi)容對大家有幫助,更多相關(guān)知識,歡迎關(guān)注億速云行業(yè)資訊頻道!
免責(zé)聲明:本站發(fā)布的內(nèi)容(圖片、視頻和文字)以原創(chuàng)、轉(zhuǎn)載和分享為主,文章觀點不代表本網(wǎng)站立場,如果涉及侵權(quán)請聯(lián)系站長郵箱:is@yisu.com進(jìn)行舉報,并提供相關(guān)證據(jù),一經(jīng)查實,將立刻刪除涉嫌侵權(quán)內(nèi)容。