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From "George Aroush" <geo...@aroush.net>
Subject RE: Remote searching with Lucene - forward progress
Date Wed, 03 Jan 2007 03:25:21 GMT
Hi Robert,

Sorry, but I am not understanding what's going on here.  What modification
you are referring to that "Elena" and you made?  Was there some private
email exchange?

In any case, one other option there is to provide remote searching with
Lucene.Net is to port the existing solution in 1.4 to 2.0 (or maybe even
1.9.1)  If you or some has the cycles and want to take on this task, let us
know and go for it.

Sorting works with MultiSearcher.  Make sure you are using the latest
release of 1.9.1 or 2.0 ("final" in both cases.)

I can't tell you much about Lucene.Net and WAN since I have not used it (I
don't have a need for it, yet.)  Since you say you have written a solution,
and it sounds like a good one, can you contribute it to ASP / Lucene.Net?
If you can do so, make sure you have the appropriate ASF copyright message
on each file, a README.TXT file, a sample / demo and if possible an NUnit
test for the code.

Regards,

-- George Aroush


-----Original Message-----
From: Robert Boulanger [mailto:robert@boulanger.at] 
Sent: Tuesday, January 02, 2007 6:19 PM
To: lucene-net-dev@incubator.apache.org
Subject: Re: Remote searching with Lucene - forward progress

Hi Jeff,

thanks for the update.
Here the status from my side so far:

I worked until I dropped the last message sucessfully with the modifications
Elena and I described before. I did nothing else since I waited and hoped
for any other progress from other sides, but wondered why the suggested
fixes never went into the releases of 1.9.
Anyhow, an other issue I  found is that the sorting seems not to work
correctly when using remote searching features. (And maybe when using
MultiSearcher in general) So it looks like each index is sorted, but not the
hits collection of the multisearcher itself.
But the major issue I found was, that remote searches over a WAN, means
Inernet or a VPN for example takes about 100 time so long as the same query
within a LAN. ( means 7 seconds instead of 0.07 secs). So I think the Lucene
Remote Query relays on heavy bidirectional Network Traffic, means not
transporting a lot of data, but a lot of single calls which makes it slow in
a WAN Environment.

Therefore I wrote my own Client Server Wrapper for this which does things in
a single call to each remote index, and which is possible now also again
with Lucene 1.3 if necessary.
I'm also able to do this in a cascading way, means each queryserver can be
configured to forward the query to other servers and they again, and so on,
and so on. hereby is ensured that endless loops are not possible (Server a
calls b which calls again a) and the API allows the passing of a parameter
which defines how deep (in the hierarchy of configured
servers)  the search should be forwarded. The end result again has correct
sorting. I also don't use any multisearchers here, just normal indexreaders.

The whole architecture has nothing to do with Lucene itself, except the fact
that Lucene is used for searching, but if anybody has interest in this, let
me know, I can build a template or example how to do this and post it
anywhere.

Cheers

Robert


Jeff Rodenburg schrieb:
> Hi Robert, et. al -
>
> No, I've not missed updating the list.  I've been a bit busy with 
> other things but have been working to resolve some serialization 
> issues that are down in the core of .Net Remoting.  The Lucene 2.0 
> codebase has been problematic inside of the remoting architecture.  
> Rather than continue to update the list with notifications about a 
> lack of progress, I've opted to attempt to address those issues and 
> make an announcement when I'd reached success.
>
> So, no news for now.
>
> thanks,
> jeff
>
> On 12/3/06, Robert Boulanger <robert@boulanger.at> wrote:
>>
>> Hi Jeff,
>>
>> concerning the message thread below which I began in August this 
>> year, I wonder if there is any progress on your side so far.
>> Maybe I missed something in the mailinglist (what I expect), since I 
>> was busy with other stuff,  but the last note from you concerning 
>> remote search I find here was from september 13th.
>> So, since I'm on this topic again, I just want to know, whether you 
>> released anything in the past months what I'm just not seeing or if 
>> you are still on the issue you are describing in your last note.
>> thanks for replying
>>
>> best regards
>>
>> --Robert
>>
>>
>>
>> Jeff Rodenburg schrieb:
>> > An update on the Remote Searching project I'm bringing forward.  
>> > I've completed the base code for hand-off to the community.  I'm 
>> > presently working through a remoting/serialization issue that's 
>> > popped up
>> recently.
>> > This appears to be something new in the Lucene 2.0 release.  I'm
>> working
>> > through that issue now, but I haven no expectation of when that's 
>> > resolved.
>> >
>> > Rather than release a non-working system, I'm going to resolve this 
>> > problem first.  Once things are working appropriately, I'll send 
>> > out a release message.
>> >
>> > Thanks and if you have remoting experience and suggestions, feel
>> free to
>> > ping me.  :-)
>> >
>> > cheers,
>> > jeff r.
>> >
>> >
>> > On 9/7/06, Jeff Rodenburg <jeff.rodenburg@gmail.com> wrote:
>> >>
>> >> All -
>> >>
>> >> Another update on the remote searching application code that's 
>> >> been mentioned in this thread.  I'm near completion of the entire 
>> >> collection of files that are needed for this project -- libraries, 
>> >> applications,
>> unit
>> >> tests, and documentation.  There's quite a bit to this, and thanks
>> for
>> >> everybody's patience as I assemble the code into something that's 
>> >> less than confusing.  There are several working pieces, so I'm 
>> >> packaging it for consumption.
>> >>
>> >> I expect to have this available sometime in the next few days,
>> barring
>> >> things like my life and regular job from getting in the way.  
>> >> Again, I'll share an announcement to the list when I've made the 
>> >> files available.
>> >>
>> >> Thanks,
>> >> jeff r.
>> >>
>> >>
>> >>
>> >> On 8/26/06, Jeff Rodenburg <jeff.rodenburg@gmail.com> wrote:
>> >> >
>> >> > As promised, an update to the list.
>> >> >
>> >> > I have code ready for delivery, if I can get svn access to the
>> contrib
>> >> > section.  A request has been made for this but it's going 
>> >> > nowhere,
>> >> so I'm
>> >> > going to find another place to host the files.
>> >> >
>> >> > There's quite a bit of documentation behind this so I'm working 
>> >> > diligently to explain how this works.  If anyone has a place to
>> >> hold the
>> >> > code until the uber-powers at apache decide to grant me access, 
>> >> > we
>> >> would
>> >> > greatly appreciate the assistance.
>> >> >
>> >> > cheers,
>> >> > jeff r.
>> >> >
>> >> >
>> >> >
>> >> > On 8/23/06, Jeff Rodenburg < jeff.rodenburg@gmail.com> wrote:
>> >> > >
>> >> > > Just a follow-up to everyone on this topic.  I received a lot

>> >> > > of offlist mail about this, so this message has a rather wide
>> >> distribution.
>> >> > >
>> >> > > I'm in process of modifying the code for our distributed 
>> >> > > search components so that they're generic enough for general 
>> >> > > usage and
>> >> public
>> >> > > consumption.  This is taking a little of my time, but 
>> >> > > nonetheless
>> >> I expect
>> >> > > to complete it soon.
>> >> > >
>> >> > > As for distributing the code, it will be located in the 
>> >> > > contrib portion of the Lucene.Net repository at apache.org . 

>> >> > > There is
>> some
>> >> > > logistic work involved, but ideally this is moving forward.
>> >> > >
>> >> > > As soon as I have more information to relay, I'll pass it 
>> >> > > along
>> >> to the
>> >> > > list.
>> >> > >
>> >> > > cheers,
>> >> > > jeff r.
>> >> > >
>> >> > >
>> >> > >
>> >> > >
>> >> > > On 8/21/06, Jeff Rodenburg < jeff.rodenburg@gmail.com> wrote:
>> >> > > >
>> >> > > > Hello all -
>> >> > > >
>> >> > > > I've been watching this thread to follow the direction and
>> >> thought I
>> >> > > > might be able to offer some assistance.  I run a search 
>> >> > > > system
>> >> that involves
>> >> > > > 4 separate search servers -- 3 serving search objects via
>> >> RemoteSearchable,
>> >> > > > and a 4th that serves in an index updating role.
>> >> > > >
>> >> > > > The codebase for Lucene.Net provides all the library
>> routines one
>> >> > > > needs to provide distributed search capabilities, but does

>> >> > > > not
>> >> provide
>> >> > > > facilities for distributed search operation -- nor should
it.
>> >> The ideas
>> >> > > > presented here are certainly possible; I've implemented a
>> >> working operation
>> >> > > > without requiring the changes described here.  I'm confident

>> >> > > > in
>> >> our
>> >> > > > implementation; for the calendar year, our 
>> >> > > > uptime/availability
>> >> of search
>> >> > > > services is 99.99%.  Our only outage was related to network

>> >> > > > hardware, otherwise we're sitting solid at 100%.
>> >> > > >
>> >> > > > I've been authorized to provide our operational code for
>> >> distributed
>> >> > > > search under Lucene.Net to the community at large.  Some
of 
>> >> > > > the
>> >> code
>> >> > > > is customized to our operation, but for the most part it's
>> >> rather generic.
>> >> > > > We started the project under Lucene v1.4.3, but the 
>> >> > > > operational aspect still applies under v1.9.
>> >> > > >
>> >> > > > The system consists of a LuceneServer, which provides
>> >> searchability
>> >> > > > against indexes as defined in XML configuration files.  In
>> >> addition, an
>> >> > > > IndexUpdateServer provides master index updating, 
>> >> > > > master/slave
>> >> index
>> >> > > > replication and automated index maintenance.  Integration

>> >> > > > with
>> >> our web site
>> >> > > > ensures the index stays available, updated and current.
>> >> There's a great
>> >> > > > deal of applied knowledge and learned behavior of many of

>> >> > > > the
>> >> underlying
>> >> > > > sub-system components that distributed search under 
>> >> > > > Lucene.Net
>> >> makes
>> >> > > > use of -- .Net remoting, garbage collection, etc.
>> >> > > >
>> >> > > > If anyone has interest, please reply.  Contributing this

>> >> > > > code requires a little cleanup of our customization work,
so 
>> >> > > > my
>> >> response may not
>> >> > > > be immediate but I would make efforts to release the code
in
>> >> short order.
>> >> > > >
>> >> > > > thanks,
>> >> > > > jeff r.
>> >> > > >
>> >> > > >
>> >> > > >
>> >> > > >
>> >> > > > On 8/19/06, Robert Boulanger < robert@boulanger.at>
wrote:
>> >> > > > >
>> >> > > > > Hi Elena, hi Rest,
>> >> > > > >
>> >> > > > > > Dear All,
>> >> > > > > >
>> >> > > > > > The application I am working on is intended to
make use 
>> >> > > > > > of
>> the
>> >> > > > > > distributed search capabilities of the Lucene library.

>> While
>> >> > > > > trying to
>> >> > > > > > work with the Lucene's RemoteSearchable class,
I faced 
>> >> > > > > > some
>> >> > > > > problems
>> >> > > > > > cased by the current Lucene implementation. In
following
>> I'll
>> >> > > > > try to
>> >> > > > > > describe them, as well as the possible ways of
their
>> >> solution, I
>> >> > > > > > identified. The most important question for me
is, if 
>> >> > > > > > these
>> >> > > > > changes
>> >> > > > > > have a chance to be integrated in the coming Lucene
>> versions,
>> >> > > > > such
>> >> > > > > > that remote searches would really become feasible.
I 
>> >> > > > > > would
>> >> > > > > appreciate
>> >> > > > > > any feedback.
>> >> > > > >
>> >> > > > > Same problem for me and I found some more issues which
I
>> explain
>> >> > > > > below:
>> >> > > > >
>> >> > > > > >
>> >> > > > > > The first problem concerns the construction of
the
>> >> > > > > RemoteSearchable
>> >> > > > > > object. .Net framework allows for both, server
and 
>> >> > > > > > client
>> >> > > > > activation
>> >> > > > > > models of the remote objects. Currently, 
>> >> > > > > > RemoteSearchable
>> >> class
>> >> > > > > > possesses only one constructor that requires knowledge

>> >> > > > > > of a
>> >> > > > > local
>> >> > > > > > Searchable object:
>> >> > > > > >
>> >> > > > > > public RemoteSearchable(Lucene.Net.Search.Searchable

>> >> > > > > > local)
>> >> > > > > >
>> >> > > > > I just added a new constructor to RemoteSearchable public

>> >> > > > > RemoteSearchable(): base() { this.local = this.local;
}
>> >> > > > >
>> >> > > > > not the fine method but for me it works so far.
>> >> > > > >
>> >> > > > > > Since this "local" object is located on the server,
>> >> knowledge of
>> >> > > > > the
>> >> > > > > > server's index paths is needed for its creation.

>> >> > > > > > However,
>> >> there
>> >> > > > > are at
>> >> > > > > > least some scenarios where only the server, but
not the
>> >> client,
>> >> > > > > knows
>> >> > > > > > where the indexes are stored on the server side.
I think
>> this
>> >> > > > > problem
>> >> > > > > > could be solved by extending RemoteSearchable class
with 
>> >> > > > > > a
>> >> > > > > standard
>> >> > > > > > constructor that reads the names of the indexes
to be
>> >> published
>> >> > > > > out of
>> >> > > > > > a configuration file on the server side.
>> >> > > > > >
>> >> > > > > My "Server" now implements a Class which inherits directly
>> from
>> >> > > > > Remote
>> >> > > > > Searchable.
>> >> > > > > in the parameterless constructor there I read the server
>> sided
>> >> > > > > configfile which contains the index location , create
a 
>> >> > > > > new IndexReader and pass it as Argument to MyBase.New()

>> >> > > > > See sample below.
>> >> > > > >
>> >> > > > > > 2. Bug in Term construction
>> >> > > > > [snip]
>> >> > > > >
>> >> > > > > This whole chapter was very useful and I can commit
>> everything
>> >> > > > > works
>> >> > > > > fine from there on.
>> >> > > > >
>> >> > > > > But there is still a bug in FieldDocSortedHitQueue line
>> 130 and
>> >> > > > > below:
>> >> > > > > I figured out that the castings are not working when
the
>> >> system is
>> >> > > > > running in a non english globalization context.
>> >> > > > > The String in docAFields[i] which might be for example
>> >> 1.345678 is
>> >> > > > > casted to 1345678.0 since the decimal sign is
>> misinterpreted in
>> >> > > > > German
>> >> > > > > systems as it seems.
>> >> > > > > So the casting results in an overflow.
>> >> > > > >
>> >> > > > > So I changed it as follows:
>> >> > > > >
>> >> > > > > case SortField.SCORE:
>> >> > > > > float r1 = (float)Convert.ToSingle(docA.fields[i],
>> >> > > > > System.Globalization.NumberFormatInfo.InvariantInfo
); 
>> >> > > > > float r2 = (float)Convert.ToSingle(docA.fields[i],
>> >> > > > > System.Globalization.NumberFormatInfo.InvariantInfo);
>> >> > > > > if (r1 > r2)
>> >> > > > > c = - 1;
>> >> > > > > if (r1 < r2)
>> >> > > > > c = 1;
>> >> > > > > break;
>> >> > > > >
>> >> > > > > Same in line 172 and 174:
>> >> > > > >
>> >> > > > > float f1 = (float)Convert.ToSingle(docA.fields[i],
>> >> > > > > System.Globalization.NumberFormatInfo.InvariantInfo);
>> >> > > > > //UPGRADE_TODO: The equivalent in .NET for method 
>> >> > > > > 'java.lang.Float.floatValue' may return a different
value.
>> >> > > > >
>> >> > > > >
>> >>
>>
"ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContext
WindowIndex'&keyword='jlca1043'" 
>>
>> >>
>> >> > > > > float f2 = (float)Convert.ToSingle(docB.fields[i],
>> >> > > > > System.Globalization.NumberFormatInfo.InvariantInfo
);
>> >> > > > >
>> >> > > > >
>> >> > > > >
>> >> > > > > A tiny Client Server Solution now looks like this (Here
in
>> >> VB.NET)
>> >> > > > > SERVER:
>> >> > > > > Public Class RemoteQuery
>> >> > > > > Inherits RemoteSearchable
>> >> > > > > Public Sub New()
>> >> > > > > MyBase.New(New IndexSearcher("C:\lucene\index")) End
Sub 
>> >> > > > > Public Sub New(ByVal local As Searchable)
>> >> > > > > MyBase.New(local)
>> >> > > > > End Sub
>> >> > > > >
>> >> > > > > End Class
>> >> > > > >
>> >> > > > > Module Module1
>> >> > > > > Public Sub Main(ByVal args As System.String()) Dim chnl
As 
>> >> > > > > New HttpChannel(8888) ChannelServices.RegisterChannel

>> >> > > > > (chnl, False) Dim indexName As System.String = Nothing

>> >> > > > > RemotingConfiguration.RegisterWellKnownServiceType
>> >> > > > > (GetType(RemoteQuery),
>> >> > > > > "Searchable", WellKnownObjectMode.Singleton)
>> >> > > > > System.Console.ReadLine()
>> >> > > > > End Sub
>> >> > > > > End Module
>> >> > > > > CLIENT
>> >> > > > > Sub Main()
>> >> > > > > Dim searchables As Lucene.Net.Search.Searchable() =
New
>> >> > > > > Lucene.Net.Search.Searchable() {LookupRemote()} Dim

>> >> > > > > searcher As Searcher = New MultiSearcher(searchables)
Dim 
>> >> > > > > sort As New Lucene.Net.Search.Sort
>> >> > > > > sort.SetSort(Lucene.Net.Search.SortField.FIELD_SCORE)
>> >> > > > > Dim query As Query = QueryParser.Parse("Harry", "body",

>> >> > > > > New
>> >> > > > > StandardAnalyzer())
>> >> > > > > Dim result As Hits = searcher.Search (query, sort) End
Sub 
>> >> > > > > Private Function LookupRemote() As
>> Lucene.Net.Search.Searchable
>> >> > > > > Return CType(Activator.GetObject(GetType(
>> >> > > > > Lucene.Net.Search.Searchable), " 
>> >> > > > > http://192.168.8.7:8888/Searchable"),
>> >> > > > > Lucene.Net.Search.Searchable) End Function
>> >> > > > >
>> >> > > > > Hope this helps you and anybody else how has problems
with 
>> >> > > > > remotesearch so far.
>> >> > > > >
>> >> > > > > BTW: this all refer



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