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From "Armel T. Nene" <>
Subject RE: Indexing and Re-crawling site
Date Tue, 05 Dec 2006 09:18:31 GMT


I was wondering about running Nutch as Windows Services. I was able to
implement it as follow:


1.    Creating a java program that will act as a Nutch and Launcher and

2.    Download JavaService from

3.    Follow the tutorial to turn your java program in a Window service


I then was able to test it on Windows Server 2003 and XP. It works fine. If
you want to me to post the code let me know, maybe others can use it too.






-----Original Message-----
From: Lukas Vlcek [] 
Sent: 04 December 2006 22:12
Subject: Re: Indexing and Re-crawling site




I will try to use my out-dated knowledge to answer (& confuse you on) your



1.      Why does nutch has to create a new index every time when indexing,

> while it can just merge it with the old existing index? I try to change

> the

> value in the IndexMerger class to 'false' while creating an index

> therefore

> Lucene doesn't recreate a new index each time it is indexing. The problem

> with this is, I keep on having some exception when it tries to merge the

> indexes. There is a lock time out exception that is thrown by the

> IndexMerger. And consequently the index that get created. Is it possible

> to

> let nutch index by merging it with an existing index? I have to crawl

> about

> 100Gb of data and if there are only a few documents that have been

> changed,

> I don't nutch to recreate a new index because of that but update the

> existing index by merging it with the new one. I need some light on this.



This is more for Nutch experts but to me it seems that new index is

reasonable. Besides others it means that original index is still searchable

while the new index is being created (creating a new index can take long

time based on your settings). Updating one document at a time in large index

is not very optimal approach I think.


2.      What is the best way to make nutch re-crawl? I have implemented a

> class that loops the crawl process; it has a crawl interval which is set

> in

> a property file and a running status. The running status is a Boolean

> variable which is set to true if the re-crawl process is ongoing or false

> if

> it should stop. But with this approach, it seems that the index is not

> being

> fully generated. The values in the index cannot be queried. The re-crawl

> is

> in java which calls an underlying ant script to run nutch. I know most

> re-crawl are written as batch script but can you tell me which one do you

> recommended? A batch script or a loop-based java program?



I used to use batch and was happy with it.


3.      What is the best way of implementing nutch has a window service or

> unix daemon?



Sorry - what do you mean byt this?




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