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From Phil Haack <>
Subject RE: Lucene.NET Community Status
Date Mon, 01 Nov 2010 21:05:29 GMT
Hi George, 

Thanks for your input on this and setting the context straight. Quick question before I dive

How much is the software that you would need? Maybe I can help look for
sponsorship. I looked at the website and it's a bit of a mess. I don't know exactly which
product you would need and what it would cost.

As for #2/#3 what is required to get started? Do you know if the documentation must be on
the Apache site? Could we create a mirror project that just houses releases and
docs, but the official site would remain on Apache? The reason I ask is that
provides support for documentation using the MetaWeblog API (and thus Windows Live Writer)
which is a fantastic tool for documentation. It lowers the bar to documentation and I've been
using it very productively for my projects.

If it must stay on Apache, a little nudge in the right direction and I'll see what I can do
to help.


-----Original Message-----
From: George Aroush [] 
Sent: Monday, November 01, 2010 1:56 PM
Subject: RE: Lucene.NET Community Status

Let me jump in here and offer some perspective about Lucene.Net (btw, it's not Lucene.NET
:-) ).  This is based on my past involvement with the project -- since 2003 when it was on and called dotLucene.

1) Up until early this year, I have been porting and supporting Lucene.Net since ver 1.4 (back
in 2004 on to the current release on trunk ver. 2.9.2.  This is in NO WAY
to say that others have not helped or contributed.  I'm just saying that I know the history
and have the experience (I wrote and worked on search engines from 1998 to 2002).

2) Doing an initial port of a new Java Lucene release to C# Lucene is very hard; it's the
most complex part of the port even using automated tools such as JLCA and my own customize
scripts which I use pre-and port JLCA (you can search the listing on how I do the port). 
What used to take me about 1 months with 90% of tests passing took me well over 4 months (for
2.9.x) with only 10% of tests passing.  This was no easy effort and won't be easier now since
Java Lucene is using new Java language features that JLCA is not aware of (MS is not maintaining
JLCA).  Put another way, porting is hard especially when you are dealing with > 5.6 GB
source code consistent of > 610 source files.  You will know this ONLY if you have tried
it out and maintained it -- this is why no one has stepped up to do an initial port otherwise
there would be a port by now not only of Java Lucene but other projects too.

3) To simplify ports of new release, maintaining as small as possible delta between release
is very important. This was a main pain point when I ported from 2.4 to 2.9.  The in-between
ports were never done due to lack of time on my end.  See point #2.

4) Diverging away from Java Lucene, both API base and algorithm is risky and will just make
point #2 more evidence.  Not only will you now need a deep knowledge of search engines to
catch bugs, but also a deep knowledge of Lucene's internals.  Also, you risk compatibility
as well as books and existing resources on the web that cover Lucene -- hack, one can take
any Java Lucene example and easily read it as a Lucene.Net code or use Luke to debug an index.
 Keep in mind, the current port model that we have for Lucene.Net keeps the API  
one-to-one in sync with Java Lucene; just upper case method names.   
Yes, it's not fully .NET'es, but if you are looking for a search engine that is compatible
with the open source search engine standard, and it is available in C#, Lucene.Net is it.

5) Beside making the port simpler, and per point #3 above, doing a line-per-line port, and
maintaining API naming as well as the algorithm and file format of Java Lucene in C# Lucene
means a Lucene index created by Java Lucene is usable, concurrently, by C# Lucene.  I have
worked on one such project where a Java and C# code accessing the same index.  I'm not too
interested in making Lucene.Net .NET'es and end up adding more risk to the project.

6) If anyone wants a different flavor of Lucene.Net, the code is on Apache, just fork it and
start a new project.  Make it more .NET'es, use the latest that .NET has to offer, and all.
 However, until when you have first hand experience with the port, and a good knowledge of
Lucene and search engines, and the cycles to work on it, I really don't want to exercise this
idea it will die as I know few folks have tried.

7) I can't speak for the other committers or those who contributed, but for me, I do this
totally during my own time.  Each hour I spent on Lucene.Net is an hour away from my family
or anything else.  I don't get paid, and I hardly get much off my Luene.Net work on the side.
 As you may know, I was active with Lucene.Net till about early this year, (I had a family
emergency).  I want to step up again, but we need more participation than just an offer to
help or request divergence from the goal of the project, per the points that I made above.

I can go on, but the above are to clarify some of the issues and background of Lucene.Net.
 Please keep those in mind when thinking about this project and how you can contribute --
especially comments about making Lucene.Net more .NET'es -- can't start that till when you
first achieve commit-per-commit port of Java Lucene to C# Lucene.

If you agree with the above, and it makes sense to you, my suggestion is as follows:

1) Lucene.Net goes back into incubation and start all over again.
2) Start with cleaning up the webpage and make it more like other Apache project site.
3) Put together an official Lucene.Net 2.9.2 and get it released.
4) Start working on the next port.

#2, #3 can happen right away, and all that it takes to do them is coming up to speed on how-to
using existing Apache documentation.  Who is up to this task?

#4 is a bit more complicated.  I don't want to go through the port pain that I had with 2.9.0
-- it was too much.  JLCA that comes with VS 2005 is out of date; I would love to try out
a newer version from, but it is $$.

I hope the above helps and I have not offended or discouraged anyone as it isn't my intention.
 I just want to clarify few things about Lucene.Net

PS: One final point.  Look at CLucene, NLucene and few other variation of Java Lucene ports
that were done at Lucene internal level with the goal of maintaining language look feature
and look-and-fell, such as  
C++, those projects are either way out of date in terms of release
version support or offer only partial support (index read only).  I don't want to use this
to bad mouth another project, but to make a point that porting is hard if you diverge from
the core.  As is, Lucene.Net is not dead, it's slow and needs contributors who will step-up.


-- George

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