lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jason Rutherglen" <>
Subject Re: Realtime Search for Social Networks Collaboration
Date Mon, 08 Sep 2008 21:05:18 GMT
Perhaps an interesting project would be to integrate Ocean with H2 to take advantage of both models.  I'm not sure how
exactly that would work, but it seems like it would not be too
difficult.  Perhaps this would solve being able to perform faster
hierarchical queries and perhaps other types of queries that Lucene is
not capable of.

Is this something Joaquin you are interested in collaborating on?  I
am definitely interested in it.

On Sun, Sep 7, 2008 at 4:04 AM, J. Delgado <> wrote:
> On Sat, Sep 6, 2008 at 1:36 AM, Otis Gospodnetic
> <> wrote:
>> Regarding real-time search and Solr, my feeling is the focus should be on
>> first adding real-time search to Lucene, and then we'll figure out how to
>> incorporate that into Solr later.
> Otis, what do you mean exactly by "adding real-time search to Lucene"?  Note
> that Lucene, being a indexing/search library (and not a full blown search
> engine), is by definition "real-time": once you add/write a document to the
> index it becomes immediately searchable and if a document is logically
> deleted and no longer returned in a search, though physical deletion happens
> during an index optimization.
> Now, the problem of adding/deleting documents in bulk, as part of a
> transaction and making these documents available for search immediately
> after the transaction is commited sounds more like a search engine problem
> (i.e. SOLR, Nutch, Ocean), specially if these transactions are known to be
> I/O expensive and thus are usually implemented bached proceeses with some
> kind of sync mechanism, which makes them non real-time.
> For example, in my previous life, I designed and help implement a
> quasi-realtime enterprise search engine using Lucene, having a set of
> multi-threaded indexers hitting a set of multiple indexes alocatted accross
> different search services which powered a broker based distributed search
> interface. The most recent documents provided to the indexers were always
> added to the smaller in-memory (RAM) indexes which usually could absorbe the
> load of a bulk "add" transaction and later would be merged into larger disk
> based indexes and then flushed to make them ready to absorbe new fresh docs.
> We even had further partitioning of the indexes that reflected time periods
> with caps on size for them to be merged into older more archive based
> indexes which were used less (yes the search engine default search was on
> data no more than 1 month old, though user could open the time window by
> including archives).
> As for SOLR and OCEAN,  I would argue that these semi-structured search
> engines are becomming more and more like relational databases with full-text
> search capablities (without the benefit of full reletional algebra -- for
> example joins are not possible using SOLR). Notice that "real-time" CRUD
> operations and transactionality are core DB concepts adn have been studied
> and developed by database communities for aquite long time. There has been
> recent efforts on how to effeciently integrate Lucene into releational
> databases (see Lucene JVM ORACLE integration, see
> I think we should seriously look at joining efforts with open-source
> Database engine projects, written in Java (see
> in order to blend IR
> and ORM for once and for all.
> -- Joaquin
>> I've read Jason's Wiki as well.  Actually, I had to read it a number of
>> times to understand bits and pieces of it.  I have to admit there is still
>> some fuzziness about the whole things in my head - is "Ocean" something that
>> already works, a separate project on  I think so.  If so,
>> and if you are working on getting it integrated into Lucene, would it make
>> it less confusing to just refer to it as "real-time search", so there is no
>> confusion?
>> If this is to be initially integrated into Lucene, why are things like
>> replication, crowding/field collapsing, locallucene, name service, tag
>> index, etc. all mentioned there on the Wiki and bundled with description of
>> how real-time search works and is to be implemented?  I suppose mentioning
>> replication kind-of makes sense because the replication approach is closely
>> tied to real-time search - all query nodes need to see index changes fast.
>>  But Lucene itself offers no replication mechanism, so maybe the replication
>> is something to figure out separately, say on the Solr level, later on "once
>> we get there".  I think even just the essential real-time search requires
>> substantial changes to Lucene (I remember seeing large patches in JIRA),
>> which makes it hard to digest, understand, comment on, and ultimately commit
>> (hence the luke warm response, I think).  Bringing other non-essential
>> elements into discussion at the same time makes it more difficult t o
>>  process all this new stuff, at least for me.  Am I the only one who finds
>> this hard?
>> That said, it sounds like we have some discussion going (Karl...), so I
>> look forward to understanding more! :)
>> Otis
>> --
>> Sematext -- -- Lucene - Solr - Nutch
>> ----- Original Message ----
>> > From: Yonik Seeley <>
>> > To:
>> > Sent: Thursday, September 4, 2008 10:13:32 AM
>> > Subject: Re: Realtime Search for Social Networks Collaboration
>> >
>> > On Wed, Sep 3, 2008 at 6:50 PM, Jason Rutherglen
>> > wrote:
>> > > I also think it's got a
>> > > lot of things now which makes integration difficult to do properly.
>> >
>> > I agree, and that's why the major bump in version number rather than
>> > minor - we recognize that some features will need some amount of
>> > rearchitecture.
>> >
>> > > I think the problem with integration with SOLR is it was designed with
>> > > a different problem set in mind than Ocean, originally the CNET
>> > > shopping application.
>> >
>> > That was the first use of Solr, but it actually existed before that
>> > w/o any defined use other than to be a "plan B" alternative to MySQL
>> > based search servers (that's actually where some of the parameter
>> > names come from... the default /select URL instead of /search, the
>> > "rows" parameter, etc).
>> >
>> > But you're right... some things like the replication strategy were
>> > designed (well, borrowed from Doug to be exact) with the idea that it
>> > would be OK to have slightly "stale" views of the data in the range of
>> > minutes.  It just made things easier/possible at the time.  But tons
>> > of Solr and Lucene users want almost instantaneous visibility of added
>> > documents, if they can get it.  It's hardly restricted to social
>> > network applications.
>> >
>> > Bottom line is that Solr aims to be a general enterprise search
>> > platform, and getting as real-time as we can get, and as scalable as
>> > we can get are some of the top priorities going forward.
>> >
>> > -Yonik
>> >
>> > ---------------------------------------------------------------------
>> > To unsubscribe, e-mail:
>> > For additional commands, e-mail:
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail:
>> For additional commands, e-mail:

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message