Nutch的命令详解（国外英文资料）.doc

Nutch的命令详解（国外英文资料） Keyword: nutch command Nutch USES a command that can be a single command on a LAN or a step-by-step command of the entire Web. The main commands are as follows: 1. Crawl Crawl is a nickname for org.apache. Nutch. Crawl. It is a complete command for crawling and indexing processes. Method of use: Shell code The bin/nutch crawl is [-threads] [-threads] [-] [-] The bin/nutch crawl is [-threads] [-threads] [-] [-] Parameters: urlDir : a text file that contains a list of urls. It is an existing folder. [-dir d ] : Nutch keeps the working directory of the record, by default the value is:. / crawl - [date] which is the current period. [-threads n ] : the Fetcher thread count overrides the fetcher.thread.fetch value in the default configuration file (by default 10). [-depth I ] : the depth of the Nutch crawler iteration, the default value is 5. [-topn num ] : limit the previous N bar records in each iteration, and the default value is Integer. MAX_VALUE. The configuration file: Hadoop - default. XML XML hadoop - site. Nutch - default. XML XML nutch - site. XML crawl - tool. Other documents: Crawl - urlfilter. TXT 2. Readdb The Readdb command is a nickname for the org.apache. Nutch. CrawlDbReader, which returns or exports information from the crawl database (crawldb). Method of use: Shell code Bin/nutch rseaddb crawldb (-stats | - dump out_dir | - url url ) Bin/nutch rseaddb crawldb (-stats | - dump out_dir | - url url ) Parameters: crawldb : the crawldb directory. [-stats] : print all the statistics in the console [-dump out_dir ] : export the crawldb information to the file in the specified folder [-url url ] : print the statistics for the specified url Example: Shell code $bin/nutch readdb fullindex/crawldb-stats $bin/nutch readdb fullindex/crawldb-stats CrawlDb statistics start: fullindex/CrawlDb The Statistics for CrawlDb: fullindex/CrawlDb TOTAL urls: 468030 Retry 0:467361 Retry 1:622 Retry 2:32 Retry 3:15 Min score: 0.0 Avg score