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From "Alan D. Cabrera" <>
Subject Re: [VOTE] Incubate Lucene Connector Framework
Date Sat, 09 Jan 2010 14:29:09 GMT


On Jan 8, 2010, at 5:51 AM, Grant Ingersoll wrote:

> Hi,
> Given the lack of response on the proposal, I'll assume lazy  
> consensus and call a vote.
> On behalf of the Lucene PMC, I'd like to propose incubation for a  
> new Lucene
> subproject called the Lucene Connector Framework (LCF). I think we  
> have all the
> necessary bits in place for the proposal to go forward.
> Proposal:
> [] +1. Accept LCF into the Incubator.
> [] 0.  Don't care.
> [] -1. Do not accept (and why.)
> Here's my +1.
> Thanks, Grant Ingersoll
> ------ Wiki Text Copied Below -----
> Lucene Connector Framework
> Abstract
> Many, many search engines, as well as other applications, have a  
> need to connect
> with content repositories (SharePoint, CMS, Documentum, etc.) in a  
> standard
> manner. The Lucene Connector Framework (LCF) is a project aimed at  
> building out
> these connectors in open source under the Apache brand.
> Proposal
> The goal of LCF is to create a viable Lucene subproject aimed at  
> delivering a
> best of breed connector framework under the Apache Lucene name. As a  
> framework,
> the project will not only provide a way to connect to individual  
> repositories,
> but also a mechanism for plugging in new connectors or custom  
> connectors in a
> straightforward manner.
> A connector framework is vital for search engines and other tools  
> that need to
> access data located in corporate repositories. By abstracting the  
> problem into a
> framework, applications can code to a set of well-defined interfaces  
> instead of
> having to use a different interface for each connector.
> Connector Framework is an extendible incremental crawler, which uses  
> a database
> to manage configuration and crawl history, and provides reasonably  
> high
> performance in accessing content in multiple repositories for the  
> main purpose
> of search engine indexing. Connector Framework also establishes a
> repository-specific security model which can be used to limit search  
> user access
> to repository content based on a user's identity. Connector  
> Framework also
> includes existing connectors and authorities for:
> • File system • Windows shares • JDBC-supported databases • RSS  
> feeds • General websites • LiveLink [from OpenText]
> • Documentum [from EMC] • SharePoint [from Microsoft]
> • Meridio [from Meridio] • Memex [from Memex] • FileNet [from IBM]
> Key design points for Connector Framework are as follows:
> • Extendability - you can add new connectors for new repositories,  
> and new
> authorities for specific repository security models • Incrementality  
> - the ability to process only what changed between crawls, in
> a repository-specific manner • Restartability - using a database  
> with ACID properties to insure that crawls
> are safe against process interruption or machine shutdown • Security  
> - establishing a model of security tokens that allows a search
> engine to enforce a repository's security model • Limited footprint  
> - ability to operate reliably within a fixed amount of
> process memory, regardless of configuration • Performance -  
> management of connector-specific resources to maximize overall
> thoughput • Transparency - ability to generate reports on the  
> activity of all crawls and
> repository connections
> Background
> MetaCarta originally approached Grant Ingersoll from the Lucene PMC  
> about
> donating their existing connector framework to the Lucene PMC. After  
> some
> discussion about accepting it as a software grant, the PMC decided  
> it would be
> best to incubate the project first.
> Rationale
> The Connector Framework fills an often significant gap in the Lucene  
> experience,
> namely, how to get content locked away in a content repository into
> Lucene/Solr/Nutch/Mahout/Tika. Naturally, many other tools (search  
> engines and
> others) will also have this same problem. A Connector Framework  
> would also be
> useful for someone wishing to migrate between content repositories,  
> too.
> Current Status
> Connector Framework has been under development and in use in the  
> field for close
> to five years, deployed on a MetaCarta search appliance. Almost all  
> development
> of the project has been done by Karl Wright  
> ( ). Some
> individual connectors were developed initially by contractors hired by
> MetaCarta, Inc., but maintenance and further development is  
> currently handled by
> the MetaCarta team.
> Development of Connector Framework can therefore be viewed as core  
> framework
> development, plus development of individual connectors. Core framework
> development is currently not a terribly collaborative process, as  
> there are no
> maintainers of the core functionality other than Mr. Wright.  
> Development of new
> connectors has been done in the past in a much more collaborative  
> way by
> supplying a developer with a "development kit", and then integrating  
> the
> resulting connector (with whatever changes might have been  
> necessary) into the
> source tree.
> Reasonable efforts have been made to maintain the generality of the  
> code base
> during the time that MetaCarta has owned it. Nevertheless, certain
> MetaCarta-specific changes have been made which may require review and
> modification. The following areas probably need to be addressed in  
> the code
> before graduation can occur:
> • Branding. The UI brands it as a MetaCarta project.
> • Package names. Package names would have to be changed. • How  
> Connector Framework handles document delivery needs to be  
> generalized, at
> least for a single, configurable target output connector, and  
> perhaps for
> multiple, independently-configurable targets. Simple example output  
> connectors
> need to be written. Work in this direction is currently underway at  
> MetaCarta
> and may or may not be complete at the time of the code handover.
> • Connector Framework-specific dependent package modifications need  
> to be
> addressed somehow. For instance, the following projects that  
> Connector Framework
> depends upon have been modified, but the modifications have not been  
> accepted
> upstream: commons-httpclient NTLMv2 and NTLM2 support [RSS, Web,  
> SharePoint,
> Meridio, and Livelink connectors]; commons-httpclient custom HTTPS  
> protocol
> factory support [Web, SharePoint, Meridio, and Livelink connectors];  
> xerces
> ability to handle non-legal RSS feeds [RSS and Web connectors]
> • MetaCarta-specific features, like document templates, are  
> explicitly handled
> by the UI and the infrastructure. These features should be  
> generalized so that
> they are controlled by the choice of output connector.
> • Some specific hooks, namely support for configuration change  
> notification,
> and for database maintenance notification, may need to be made more  
> generic. • Share Connector has a "fingerprinting" feature, which  
> prefilters documents
> based on a document type it surmises using a document inspection  
> technique. This
> feature is only viable at the moment for very basic document types.  
> It should
> either be removed, or generalized significantly to be much more  
> flexible. • Documentation needs to be fleshed out, including javadoc  
> and overall usage
> documents. • Tests need to be written and/or ported from MetaCarta's  
> test suite.
> Longer term, the project will likely grow into a more distributed  
> crawler, where
> multiple machines might well be involved in coordinated crawling  
> activity.
> Meritocracy
> Building the community using a meritocratic approach is very  
> important to the
> success of LCF. We know many, many people in the search space (and  
> otherwise)
> have either written their own connectors or are in need of  
> connectors. Thus, we
> expect a meritocratic community will lead to widespread participation.
> Community
> Our hope is that our existing code, features and capabilities will  
> attract a
> large community of both developers and users. We also believe that  
> other
> organizations will find this project interesting and relevant, and  
> contribute
> resources.
> The user community of LCF would be similar to that of the other  
> Lucene projects,
> and in many cases they would overlap.
> Core Developers
> See the initial committer list below.
> Alignment
> We expect LCF will align quite well with the existing Lucene  
> community and will
> also provide significant value to other ASF and non-ASF projects as  
> well as many
> companies and individuals looking to access their content  
> repositories in a
> programmatic fashion.
> Known Risks
> Orphaned Products
> The Connector Framework is an important piece of any search engine,  
> including
> MetaCarta's, as it provides the primary mechanism for getting  
> content out of a
> repository and into the search engine's index. Thus, we don't expect  
> it will be
> orphaned anytime soon. Once the project is established and the code is
> available, we expect to attract not only other search companies, but  
> others with
> similar needs.
> Inexperience with Open Source
> Grant Ingersoll, Ryan McKinley and Simon Willnauer provide the  
> majority of the
> experience with Open Source at the ASF, but all of the initial  
> committers are
> familiar with Open Source and have contributed to other open source  
> projects.
> Homogeneous Developers
> The current list of committers are mostly members of either the  
> MetaCarta or
> Lucid Imagination developer team, but several are not. Additionally,  
> we are
> actively recruiting other developers.
> Reliance on Salaried Developers
> We have a variety of committers represented. Some are being paid to  
> work on the
> project and some are not.
> Cryptography
> Connector Framework itself has no real cryptography component,  
> although it does
> currently obfuscate passwords it saves to the database or to a  
> configuration
> file using a proprietary algorithm. The algorithm is present simply  
> to avoid
> using cleartext and is not secure in any sense other than by  
> obscurity.
> Various connectors, such as Share Connector, Web Connector, RSS  
> Connector,
> SharePoint Connector, LiveLink Connector, and Meridio Connector make  
> use of
> cryptographic principles via secondary libraries. Specifically,  
> these connectors
> support NTLM, NTLMv2, and NTLM2 Session authentication via commons- 
> httpclient
> and jCIFS. The changes to commons-httpclient necessary to support  
> these
> varieties of Windows protocols have not yet been accepted upstream  
> by the Apache
> httpclient project.
> It is unknown at this time exactly to what degree the Oracle JDBC  
> driver, the
> jtds JDBC driver, or the Postgresql JDBC driver uses cryptography.  
> Also, the
> FileNet API class, the Memex API classes, the OpenText LAPI api  
> classes, and the
> Documentum DFC classes all may or may not use cryptography.
> Legal Concerns
> Some of the connectors in the existing framework require paid  
> licenses to use.
> We will need to evaluate each connector to see what can be  
> appropriately
> included. For those connectors that require a paid license, we will  
> need to
> determine a plan for including the wrapper code without the  
> underlying bindings
> in a legal manner. We expect we can provide the wrapper code without  
> the binding
> and that the code will thus only be compilable by someone who has  
> access to the
> binding. (This is what Google has done for their individual  
> connectors). Longer
> term, we expect to demonstrate to the companies with proprietary  
> connectors why
> it is more valuable for them to open up their specific connector  
> pieces to give
> broader access to people looking to leverage their content in the  
> repository.
> Trademark
> The project is being rebranded from a MetaCarta internal name to the  
> Lucene
> Connector Framework, which will be an ASF mark.
> Relationships with Other Apache Products
> We expect almost all of the Apache Lucene ecosystem will benefit  
> from having a
> standard way of connecting to content repositories. Additionally,  
> users of UIMA
> should also benefit. We also see an especially tight connection with  
> Tika, as
> much of the content in these types of repositories are "rich"  
> document types
> which will then need their content extracted.
> An Excessive Fascination with the Apache Brand
> All of us are familiar with the value that Apache brings to a  
> project in
> building out a community. We also are all significant users of  
> Apache Lucene and
> related tools (Solr, Nutch, Mahout, Tika) and expect a close  
> relationship with
> those projects will help significantly grow the LCF community.
> Documentation
> MetaCarta has end-user documentation for Lucene Connector Framework,  
> which might
> function as the core the open-source end-user documentation. The  
> documentation
> is in LaTeX form, and thus usable sources can readily be extracted.  
> Research as
> to any ownership issues for the documentation as it stands still  
> needs to be
> examined.
> The existing java doc of the code, while fairly extensive, needs  
> review and
> perhaps augmentation to insure it meets the needs of an ASF project.  
> Significant
> attention to maintaining its accuracy was made during MetaCarta's  
> ownership of
> the code base.
> Initial Source
> All initial sources will be coming from MetaCarta, Inc., with the  
> goal of
> folding in changes from others shortly thereafter.
> Source and Intellectual Property Submission Plan
> Code IP grants need to be made from MetaCarta, Inc. But, in  
> addition, several
> connectors (notably Documentum, LiveLink, Memex, and FileNet) rely  
> directly on
> client API's in order to be compiled. Another connector (JDBC)  
> relies on the
> existence of the Oracle JDBC Driver in the classpath in order to  
> enable crawls
> against Oracle databases.
> It is unlikely that EMC, OpenText, Memex, or IBM would grant
> Apache-license-compatible use of these client libraries. Thus, the  
> expectation
> is that users of these connectors obtain the necessary client  
> libraries from the
> owners prior to building or using the corresponding connector. An  
> alternative
> would be to undertake a clean-room implementation of the client  
> API's, which may
> well yield suitable results in some cases (LiveLink, Memex,  
> FileNet), while
> being out of reach in others (Documentum). Conditional compilation,  
> for the
> short term, is thus likely to be a necessity.
> Other external dependencies, such as jCIFS for the Share Connector,  
> are licensed
> with LGPL, and thus may need to be treated in a manner similar to  
> the closed
> API's even though they are open source. These include the postgresql  
> driver, and JTDS.
> The Lucene Connector Framework core and individual connectors are  
> completely
> separable, and many of the connectors require no third party licenses.
> Therefore, there is significant utility for this project even in the  
> absence of
> any third-party software grants, or clean-room engineering.
> The software grant will be faxed to the Apache Software Foundation  
> if and when
> the proposal herein described is accepted. MetaCarta patents are not  
> infringed
> by this grant. Also, MetaCarta trademarks are not included in this  
> grant.
> External Dependencies
> The project dependencies, other than on other Apache projects, are  
> as follows:
> The ConnectorFramework core currently uses the Bitmechanic JDBC pool  
> driver,
> which is BSD licensed, and the Postgresql JDBC driver, which is also  
> licensed.
> The LiveLink Connector relies on LAPI, which is privately licensed  
> by OpenText.
> The Documentum Connector relies on DFC, which is privately licensed  
> by EMC. The
> Share Connector relies on jCIFS, which is LGPL. The Memex Connector  
> relies on
> privately licensed java libraries from Memex. The FileNet Connector  
> relies on
> privately licensed java libraries from IBM.
> Required Resources
> • Mailing lists • connectors-private (with moderated subscriptions)  
> • connectors-user@ • connectors-dev@ • connectors-commit@ •  
> Subversion directory •
> • Website • Confluence (CONNECTORS) • Issue Tracking • JIRA  
> Initial Committers
> Names of initial committers with affiliation and current ASF status:
> • Karl Wright (kwright at metacarta) • Josiah Strandberg  
> (jstrandberg at metacarta) • Ken Baker (bakerkj at metacarta) • Marc  
> Meadows (mam at metacarta) • Grant Ingersoll ( gsingers@a.o Lucid  
> Imagination, ASF Member)
> • Brian Pinkerton (brian.pinkerton at Lucid Imagination) • Simon  
> Willnauer (simonw at apache org, Committer on Lucene Java and Lucene
> Open Relevance Project) • Ryan McKinley (ryan at apache org,  
> Committer on Lucene and Solr)
> • Robert Muir (rmuir at apache org, Committer on Lucene and Open  
> Relevance) • Sami Siren ( siren@a.o , Committer on Nutch and Tika)
> • Otis Gospodnetic ( otis@a.o , Committer on Lucene, Solr, Nutch,  
> Mahout, and
> Open Relevance Project)
> • Shalin Shekhar Mangar ( shalin@a.o , AOL, Committer on Apache Solr)
> • Noble Paul ( noble@a.o , AOL, Committer on Apache Solr)
> • George Aroush (george at, Committer on Lucene.Net)
> Sponsors
> Champion
> • Grant Ingersoll
> Nominated Mentors
> • Grant Ingersoll • Jukka Zitting • Gianugo Rabellino
> Sponsoring Entity
> • Apache Lucene PMC: Message ID:
> in private@lucene.a.o

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