Remote searching with Lucene - project update

[Jeff Rodenburg <je...@gmail.com>]

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 <je...@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 <je...@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='!DefaultContextWindowIndex'&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 refers Version 1.9rc1
> > > >
> > > > --Robert Boulanger
> > > >
> > >
> > >
> >
>