lucenenet-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Robert Boulanger <rob...@boulanger.at>
Subject Re: Remote searching with Lucene - forward progress
Date Tue, 02 Jan 2007 23:18:37 GMT
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='!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 refer



Mime
View raw message