hi luo: Nutch使用的确是Lucene索引，不过将索引放在HDFS上面是为了利用Hadoop平台的计算性能对索引进行合并等一些操作。在hadoop平台上进行这些操作比单机处理强很多。处理完成之后，可以将索引下载到本地进行访问，并不是提供搜索服务的时候也是在hdfs上面的。
使用mapfile sequencefile是为了利用Hadoop平台处理数据，最终生成索引。mapfile sequencefile并不是索引存储的方式，里面存储的有原始数据，比如网页源码……（这点我说的只是大概意思，可以参考Hadoop权威指南关于mapfile sequencefile的介绍，了解他们的特性） On Wed, Jun 30, 2010 at 10:06 AM, 罗磊 <[email protected]> wrote: > Hi all: > > I heard that Nutch put Lucene index file on HDFS, and wait for searcher. As > far as I know, HDFS is not designed for low-latency visiting. > > So why Nutch put index file on HDFS? why not stored on local filesystem, and > use normally RPC to call search function? > > I also heard that Nutch used MapFile a lot, do you think put those data on > HBase is a good alternative? > > Thank you in advance >
