1 配置因素 fetcher.server.delay 0.0 The number of seconds the fetcher will delay between successive requests to the same server.2 机器人协议因素FetchItemQueue fiq = fetchQueues.getFetchItemQueue(fit.queueID); fiq.crawlDelay = rules.getCrawlDelay(); if (LOG.isDebugEnabled()) {...
Fetcher类工作流程：FileInputFormat.addInputPath(job, new Path(segment, CrawlDatum.GENERATE_DIR_NAME));job.setInputFormat(InputFormat.class);----------------第一部分------------------------job.setMapRunnerClass(Fetcher.class);Fetcher类实现了MapRunnable这个接口，主要完成了生产者的启动与消费者的启动。Fetcher extends Configured implements T
上次我们介绍了offset操作的原理，下面介绍消费者如何从服务端获取消息。Fetcher类的主要功能是发送Fetcher请求，获取指定消息集合，处理FetchResponse，更新消息位置。public class Fetcher<K, V> {
//client负责网络通信
private final ConsumerNetworkClient client;
fetcher.max.crawl.delay 默认是30秒，这里改为 5秒修改nutch-default.xml fetcher.max.crawl.delay 5 If the Crawl-Delay in robots.txt is set to greater than this val...
fetcher.threads.per.host<property><name>fetcher.threads.per.queue</name><value>1</value><description>This number is the maximum number of threads thatshould be allo
